Proceedings of SECON'19

Enormous global CO2 emissions associated with cement production necessitates the use of sustainable cementitious alternatives. Alkali-activated binder (AAB) which utilizes industrial wastes as precursors is a promising substitute for cement. To promote the practical use of AAB concrete, this paper presents an investigation on the mechanical and microstructural properties of ambient-cured AAB concrete. Fly ash/slag ratio is varied and the optimum mix is proposed based on compressive strength test results. Pull-out test is performed to evaluate the bond strength of ambient-cured reinforced AAB concrete. The specimen-level tests are supplemented with results from X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) along with energy-dispersive spectroscopic (EDS) analysis of the AAB paste samples. This is done to corroborate the microstructural characteristics with the mechanical properties at specimen-level. Fly ash: slag ratio of 70:30 is recommended as the optimum proportion considering both strength and economical aspects. Incorporation of slag results in the formation of the additional reaction products, refining the pore structure and enhancing strength. The AAB mix with fly ash: slag ratio of 50:50 exhibits the highest compressive strength and bond strength.

Construction industries in India are extensively using various materials such as concrete block, bricks, hollow blocks, etc. for infill walls. These blocks are bulk in weight and have transportation problems. This study aims at the feasibility of cellular lightweight concrete using fly ash, cement and synthetic based foaming agent with density 800 kg/m3. Mix design was prepared with cement to fly ash ratio as 375:375, 250:500, 500:250 kg/m3, followed by water curing. Experimental investigation was conducted on optimized mix with respect to density, compressive strength, water absorption, fire resistance, in addition to extreme environmental conditions. Micro structural studies including SEM/XRD are also performed. The results indicated that foamed concrete block and panels can be used for infill purpose with improved performance and other characteristics.

The use of supplementary cementitious materials by replacing cement makes the concrete more economical and the use of industrial wastes like fly ash for this makes the disposal method of these wastes easy and ecofriendly. Basalt fibre is an inorganic fibre manufactured from the extrusion of melted basalt rock. Basalt fibres are characterized by high corrosion and thermal resistance, lightweight and high strength. The fibres act as a proactive reinforcement that provides immediate tensile load carrying capacity when micro-cracks are developed in concrete. It has excellent mechanical and physical properties and an environmental friendly manufacturing process. The advantages are fire resistance, good resistance to chemically active environments, vibration and acoustic insulation capacity. The optimum of fly ash in concrete is found to be 20% by weight of cement. The optimum percentage of basalt fibre is 0.5% by volume of concrete. Basalt fibre addition may not be an effective method to increase concrete compressive strength. By adding basalt fibre in concrete, the split tensile strength and flexural strength can be increased up to 37.73% and 36.71% respectively. Tests on the concrete are conducted according to IS: 516-1959.

Industrial waste management constitutes one of the greatest global problems of our time, especially for large cities lacking landfill. Recycling non biodegradable wastes is a challenging task, and brick wastes are classified as this kind of waste with a long decomposition period. Since brick powder has high content of silica, it is pozzolanic in nature. So it can be used as an effective replacement for cement. The concrete structures are most likely to experience elevated temperatures during their service period due to fire. Therefore, the relative properties of concrete after exposure to fire are to be studied for the serviceability of buildings and the safety of inhabitants. In this study, experimental programs are to be performed regarding the use of brick powder for replacement of cement at elevated temperature. The different specimen samples are casted. The properties of the concrete specimens including compressive strength, SEM and XRD of the concrete after being exposed to the temperatures of 200, 400 and 600 °C and prior to experiencing heat are to be investigated. The obtained results are to be compared and the changes occurred are to be studied further.

Geopolymer is an aluminosilicate binding material synthesized by thermal activation of solid aluminosilicate base material such as GGBS and fly ash. Geopolymer concrete is produced due to alkalization of materials rich in aluminum and silicon with alkali solution, an aqueous solution of sodium hydroxide and sodium silicate. Alkali solution was varied in different molar concentration with sodium hydroxide to sodium silicate ratio of 2.5. The effect of age on geopolymer binder cured at ambient temperature and microstructure of binder were studied. The material used in this study consists of fly ash, ground granulated blast furnace slag, alkaline liquid, fine aggregate and coarse aggregate and sisal fibre. The mechanical properties of geopolymer concrete and binder with or without the sisal fibre were determined. The durability tests such as acid attack test and chloride attack for various mix samples were also conducted.

Indian ceramic production is 100 Million ton per year in the ceramic industry, about 15–30% waste is generated from the total production. Dumping of ceramic waste leads to serious environmental and dust pollution and occupy large area. To avoid these conditions, it is desirable to reduce the stockpiles of ceramic waste by recycling or other alternative methods. Stone columns are one of the versatile techniques for engineering the ground. It is the most effective solution for improving the strength of soil and thereby protecting against liquefaction with less installation time. Our aim is to investigate the feasibility of using ceramic waste as aggregates in stone columns there by reducing the waste disposal, to provide a replacement to aggregates in columns and to minimize the cost of soil stabilization. Method/analysis: Experimental study on the load settlement behavior (IS 1888–1982) in test model of Ceramic stone column, Ceramic stone columns with geotextile casing, Ceramic stone columns with horizontal arrangement of geotextile, Ceramic stone columns with both horizontal layering and casing of geotextile and to compare with the ordinary stone column. Result shows that improvement in the load carrying capacity is found less in ceramic as compared to stone column but by the introduction of geotextile casing and layering, found an increase in the load carrying capacity.

Use of glass in concrete is an interesting possibility for economy on wastage disposals. It is an amorphous material with high silica content, thus making it potentially pozzolanic when particle size is less than 75 μm [1, 2]. The amorphous silica (SiO2) in the glass powder reacts with the portlandite [Ca(OH)2] generated during cement hydration and convert to gels of calcium silicate hydrate (C–S–H) [3]. A major concern regarding the use of glass in concrete is the chemical reaction that takes place between the silica rich glass particle and the alkali in pore solution of concrete, which is called Alkali Silica Reaction. It can be very detrimental to the stability of concrete, unless appropriate precautions are taken to minimize its effects. The inclusion of fly ash in glass powder concrete has shown reduction in the alkali silica reaction and improvement in the workability and durability properties of concrete [4, 5]. This study summarizes information on the mechanical properties of concrete containing fly ash and glass powder. The main objective of this work is to study the suitability of these materials as partial replacement of cement. In this study, cement is partially replaced with fly ash and glass powder in different proportions by weight and the combined optimum percentage is determined. The properties of concrete containing optimum percentage of these materials are compared with that of control concrete. A better understanding of the performance of these materials could lead to its increased usage, consequently contributing to sustainability.

Many materials are used during construction which goes through different manufacturing and transporting process, which may adversely affect the environment. Choosing an environmentally friendly material will reduce the inimical environmental effect caused due to construction material. But for the proper selection of sustainable building material, it must be balanced against the economic performance also. So proper decision-making criteria have to be developed. This study analyses and compare five flooring materials (terrazzo, linoleum, ceramic, and marble and vinyl composition tiles) on their environmental and economic performance. The environmental impact analysis was done using the Building for Environmental and Economic Sustainability (BEES) software. The Life cycle cost of the materials was found with the help of data from various journals and from National Building estimator and Indian context. The result obtained was then analyzed using VIKOR (VIseKriterijumska Optimizacija I Kompromisno Resenje, that means: Multicriteria Optimization and Compromise Solution) to develop a combined performance score for the selection of a best suitable material. Then the Contingent Valuation Method (CVM) is utilized to estimate the environmental cost associated with the selected alternative flooring materials. The method will provide improved decision-making criteria for the selection of suitable flooring material.

Among the recent discoveries for alternatives of portland cement (PC) concrete, Alkali-activated binder (AAB) concrete is prolifically being considered as the most eco-friendly and sustainable alternative. The present study evaluates the shrinkage behaviour for three different AAB mixtures containing fly ash and/or slag at different proportions which are activated by sodium hydroxide and sodium silicate. Multiple linear regression models are developed to predict shrinkage strains of ambient-cured AAB concrete as a function of age and percentage of fly ash in the precursor. The aim of this work is to come up with a generalized equation that can predict the shrinkage of various binary blended AAB mixes cured at room temperature. The predicted models are ranked based on RMSE and then compared with the experimental data. The correlations were found to be quite satisfactory (R2 = 0.937) and can be used to estimate the shrinkage for similar AAB mixtures. It is observed that the proposed model agrees more closely with the experimental results from the present study.

Self-Compacting Concrete has gained wide use for placement in congested reinforced concrete structures with difficult casting conditions while in Self Curing Concrete, water is restricted by means of some chemical compounds to move out from the concrete body. The main problem due to acute shortage and high price of river sand led to the enormous usage of M sand in construction. Use of copper slag as a fine aggregate is a good alternative to M sand and a better remedy to the disposal of copper slag. This investigation is aimed at utilizing the benefits of both self-compacting and self-curing concrete incorporating Copper Slag. In this study, the fresh and hardened properties of M50 equivalent Self-Compacting Concrete is obtained by incorporating 15% of Fly Ash as constant. Self-curing agent Polyethylene Glycol is added in 0, 0.5,1 and 1.5% to Self-compacting Concrete and its optimum is evaluated based on strength parameters. The optimum dosage of Copper Slag by the replacement of fine aggregate in different percentages of 10, 20, 30, 40 and 50% in Self-Compacting Self-Curing Concrete is obtained and their strength parameters are compared with normal Self Compacting Self-Curing Concrete. The utilization Fly Ash and Copper Slag which indirectly facilitate waste reduction helps in maintaining the ecological balance thus reduces the consumption of cement and aggregates.

Bendable concrete also known as Engineered Cementitious Composites abbreviated as ECC is a class of ultra-ductile fibre reinforced cementitious composites, characterized by high ductility and tight crack width control. The bendable concrete has very good flexibility. Ductile property of normal concrete can be improved by using natural and artificial fibers like jute fibre and PVA fibre. In this project the strength characteristics of M30 bendable concrete is evaluated by incorporating different percentage of jute and PVA fibres and by partial replacement of cement by fly ash. The PVA and jute fibers will be added to the concrete by 0, 0.5, 1, 1.5 and 2% by weight of binders. Suppressing brittle fracture prevents the formation of wider cracks and it prevents water and other aggressive agents to penetrate easily into concrete structures thus leading to structural safety and stability.

In this paper, the effect of alkaline solution content on compressive strength and corrosion behavior of steel reinforcement in geopolymer concrete (GPC) has been evaluated. For the study, fly ash was used as the source material for preparation of geopolymer concrete. The mixture of NaOH solution (10 M and 14 M) and Na2SiO3 solution was used as the alkaline solution. Alkaline solution contents of 190 and 210 kg/m3 were used in the preparation of geopolymer concrete mixes. Sodium chloride was added at the time of preparation of GPC mixes and its concentrations were 0% and 3% by mass of geopolymer solids content. From GPC mixes, cube specimens and prismatic reinforced concrete specimens were prepared. Half-cell potential and corrosion current density by linear polarization resistance (LPR) measurement were carried out on prismatic reinforced specimens. From obtained results, it is observed that there was no systematic variation in 28 day compressive strength of GPC with alkaline solution content and the compressive strength decreased in the presence of chloride ions. Further, GPC made with higher alkaline solution content showed higher probability of occurrence of reinforcing steel corrosion and higher corrosion current density as compared to that made with lower alkaline solution content.

The cement industry contributes to 5% of global CO2 emissions and is thus one of the biggest contributors to global warming. Alkali-Activated binders offer a more sustainable solution to the problem, as they are produced from industrial wastes such as fly ash and slag. Their production has a lower environmental impact in terms of greenhouse gas emissions. Hence, AABs are sustainable and can be considered as green construction materials. Most research into the field of alkali-activated binders indicates the superiority of AABs in terms of mechanical properties and durability as compared to portland cement. This study aims to find the correlation between the flexural strength and compressive strength of alkali activated binder concrete. This is achieved by formulating a regression model which correlates the flexural and compressive strengths of AAB concrete by incorporating grade of concrete as a factor. The results of this study will promote the practical use of AABs as an alternative to portland cement.

Concrete is plastic for a very short time from being cast to final setting time. But even in this early age, the concrete shrinks and induces cracking. Aiming to mitigate the impact of shrinkage in concrete, shrinkage reducing admixtures can be used in concrete. But the effect of shrinkage reducing admixture on the plastic period of concrete is not well defined, so there is a need for study in this area. This paper quantifies the effectiveness of shrinkage reducing admixture on cracking of plastic concrete. This is achieved by measuring the slump, compressive strength and plastic shrinkage cracks of concrete mixes. ASTM C1579 based mould is used to promote the plastic shrinkage crack in concrete. To assess the performance of shrinkage reducing admixture and to determine its optimum amount 0, 0.5, 1, 2, 3 and 4% dosage were analysed. The optimum percentage of shrinkage reducing admixture was found to be 2%.

Geopolymer concrete (GPC) is an emerging sustainable construction material alternative to the conventional Ordinary Portland Cement Concrete (OPCC), which utilizes the cementitious properties of industrial or agricultural by-products such as fly ash, Ground Granulated Blast furnace Slag (GGBS), silica fume, red mud, rice husk ash (RHA) etc. activated by an alkaline solution and thereby reduce the demand for cement and the related environmental issues. In the present work, Ground Granulated Blast furnace Slag (GGBS) is blended with silica fume in various proportions at ambient temperature condition to produce the geopolymer concrete and the mechanical properties are investigated and compared with OPCC of M30 grade. Sodium hydroxide and sodium silicate solution are used as alkali activators throughout this work. The compressive strength test results show that the GGBS based geopolymer concrete (GGPC) gives high compressive strength concrete at ambient temperature conditions and the inclusion of silica fume at various percentages (10, 20, 30, 40, 50 and 60%) significantly reduced the compressive strength. However, a considerable increase in workability was observed with increasing percentage of silica fume in GGPC. The test results of GGPC blended with silica fume at 40% are comparable to OPCC of M30 grade.

Self compacting concrete (SCC) is an extremely fluid mix which does not require tamping or vibration and gains its fluid property from high proportion of fine aggregate, super plasticizers and viscosity enhancing admixtures. One of the major draw back of SCC is its cost due to the utilization of high amounts of cement and chemical admixtures. Also large scale cement production causes the discharge of high amount of CO2 into the atmosphere causing global warming and ozone layer depletion. So Ground Granulated Blast Furnace Slag (GGBS) can be used as a better substitute to cement which possessing cementitious property. Shortage of natural coarse aggregate in future can be solved by replacing it with recycled coarse aggregate from demolition waste itself. This study aim to determine the utilization of GGBS and recycled aggregate in SCC as an alternate material to cement and natural coarse aggregate by determining its workability and mechanical properties. Cement is replaced with GGBS at 20, 30, 40 and 50% by weight of cement in SCC and 40% of natural coarse aggregate is replaced with recycled aggregate (Vivek and Dhinakaran in Eng Sci Technol Int J 20:1173–1179, 2017 [2]). Optimum percentage of GGBS is evaluated by compressive, split tensile and flexural strength tests. From the experiment, the optimum percentage of GGBS obtained is 30%.

In construction industry large number of buildings are repaired and retrofitted due to the decrease in the load bearing capacity of RC beams within the life span of the building. Repair materials with reduced carbon footprint and environmental sustainability have been in great demand by the construction industry worldwide. Cement is the main constituent of the mortar used for the repair and retrofitting techniques. The production of cement is energy-intensive and releases large amount of carbon dioxide (CO2) to the atmosphere that significantly contributes to greenhouse gas emissions. It is estimated that one ton of CO2 is released into the atmosphere for every ton of ordinary Portland cement produced. Environmentally sustainable repair materials with reduced carbon footprint have been in great demand by the construction industry worldwide. Cement-free geopolymer mortars prepared from waste materials with high content of silicate aluminium and alkaline activator solution are emerging as prominent sustainable repair materials. Industrial waste Fly ash is used in this study as the replacement of cement. The current study focuses on strength comparison of cement mortar cubes and geopolymer mortar cubes in ambient curing conditions. 10M, 12M, 15M geopolymer mortar cubes are prepared for the study. Useage of geopolymer mortar leads to the reduction in cement quantity in construction industry and its use should be promoted for better performance and environmental sustainability.

In recent decades, Self compacting concrete (SCC) plays a vital role in building construction due to its unique ability to fill formwork of complex steel reinforcements by its own weight with no mechanical vibrations. Due to severe environmental impact caused by over usage of natural aggregates and water in concrete production, a novel approach in producing a sustainable SCC is by replacing natural aggregates by light weight aggregate. The lightweight aggregate used plays a vital role in enhancing the fresh and hardened properties of SCC due to its better internal curing property. This experimental investigation was conducted to study the fresh and hardened properties of SCC incorporated with sintered fly ash aggregates (Sintag). In this experimental study the coarse aggregate is replaced with various percentages replacement of Sintag such as 5, 10, 15, 20, 25 and 30% respectively. The fresh properties of SCC were studied in accordance with EFNARC guidelines. Hardened properties include compressive strength, split tensile strength, flexural strength and hardened density testing. The optimum percentage replacement was obtained as 15% replacement. The presence of internal moisture content helps to obtain hardened cement paste compared to conventional SCC. The results showed that compressive strength, split tensile strength and flexural strength of internally cured SCC has increased significantly.

An experimental investigation was conducted to study the strength characteristics of silica fume incorporated foam concrete. Light Weight Foamed concrete (LFC) has become most commercial material in construction industry for non-structural applications owing to its lesser density, stability and high thermal insulation properties. The aim of this study is to develop structural foamed concrete by using silica fume and fly ash. Constant cement: fly ash: sand ratio of 1:0.5:1.5 and W/C ratio of 0.65 was used for all mixes. The study presents the use of fly ash for partially replacing sand to produce foamed concrete. Fine silica fume is used to improve properties of foamed concrete. Four variations of foam (2, 3, 4 and 5%) were added and cement was partially replaced with silica fume of various percentages (0, 5, 10, 15 and 20%). The results indicate that foamed concrete with a density of 600–1450 kg/m3 and compressive strength of 6–13 N/mm2 can be made by using silica fume. The silica fume improved the compressive strength of foamed concrete.

Sustainable construction practice is essential for the safeguarding and manageability of our earth just as the wellbeing of ourselves and what is to come. Even if brick is one of the most common construction material, scarcity of natural materials have led to the incorporation of different types of waste into the bricks and have been investigated [1]. In the growing concern of sustainability, compressed earth bricks are more energy efficient, economic and environment friendly. The aim of this project is to study the suitability of clayey soil and crushed Oyster Shell (OS) powder using Rice Husk Ash (RHA) as binder for unfired rammed earth brick. OS is an industrial waste, disposed of in open dumps at coastal areas in huge quantities. In order to reduce the environmental problems created by the waste OS, the soil in the bricks were replaced by Oyster shell powder by varying the percentage from 5 to 20 at an interval of 5%. To evaluate the performance, tests such as compressive strength, efflorescence and total water absorption were conducted on samples of size 190 mm × 90 mm × 90 mm. Compared to conventional unfired bricks the samples showed a better compressive strength for 10% replacement.

Annual production of cement, the most important ingredient in concrete is increased by 3%. It is also a fact that the process of cement production is highly energy intensive and releases large volume of greenhouse gases like CO2 to the atmosphere. The environmental effects associated with production of Portland cement, created an urgent need to develop an alternative binder to make concrete [1]. In this respect, Davidovits introduced geopolymer technology which provides an alternative low emission binding agent to conventional cement concrete. Many research works are being carried out to replace cement either fully or partially from concrete. Geopolymer is an innovative construction material produced by polymeric reaction of alkaline liquid with alumino-silicate materials such as fly ash, blast furnace slag, rice husk ash etc., making it a promising material to replace ordinary Portland cement as a green binder for concrete production [2]. This paper presents the results based on experimental investigation on the mechanical strength of hybrid fibre (1% of polypropylene fibre from which 10% of polypropylene fibre is replaced by glass fibre) reinforced geopolymer concrete. The addition of hybrid fibre shows an increase in strength parameters with respect to geopolymer concrete without fibres.

Fly ash is most commonly used as a replacement material for cement in concrete. The fly ash based concrete mixes exhibits low initial strength development due to low pozzolanic reactivity of fly ash particles. It limits the usage of fly ash up to a certain percentage in case of cement manufacturing process and also reduces the application of high-volume fly ash structures in construction field. A number of studies had been conducted on the chemical activation of fly ash using various sulphate sources. Phosphogypsum (PG), a particular type of industrial waste material which is an another form of calcium sulphate, has not been used for this purpose. This paper presents an exploratory study on the effectiveness of phosphogypsum on activating fly ash cement system. The initial strength development of chemically activated fly ash mixes is mainly due to the formation of ettringite (AFt) and tobermorite crystals during the early age of hydration. The fly ash cement concrete mixes were prepared by replacing cement with fly ash by 15, 25, 35, 45% and these mixes were treated with 0, 6, 8, 10, 12% of phosphogypsum. The activation effect happens mainly during the first 3–7 days. The strength parameters and durability nature of chemically activated fly ash mixes were compared with that of the normal fly ash mixes. Strength tests such as compressive, split tensile and flexural strengths were conducted at age of 3, 7 and 28 days on various fly ash mixes. Durability nature of activated and non-activated fly ash mixes were studied by acid and base durability tests at age of 90 days. The obtained results indicate that the initial strength development is optimum at replacement of 35% fly ash and 8% PG. Based on the test results the chemically activated fly ash mix shows improved strength and durability nature compared to normal fly ash mixes.

Coir fibres and jute fibres are natural materials that are abundantly available in tropical regions of our country. Waste generated by the industrial and agricultural processes has created disposal and management problems, which causes serious challenges for environmental conservation. A considerable amount of coir fibres and jute fibres remain in the environment as waste, so the utilization of these materials for construction is an important step to improve sustainability and eco-friendly construction. The current study deals with the addition of coir and jute fibres to concrete such as attain sustainable construction material without sacrificing the strength of concrete. To check its suitability, test for compressive strength, split tensile strength, flexure strength and water absorption test were performed. To ensure the suitability of coir fibres and jute fibres as ingredients of concrete the results obtained from above were compared with conventional concrete. Also, a comparative study of fibre reinforced concrete and self-compacting fibre reinforced concrete was carried out. The work was carried out by conducting tests on the raw materials to determine their properties and suitability as engineering material. Concrete mix designs were prepared using the IS method for an M30 grade concrete. The specimens were cast with percentage addition of 0.7 jute fibre and 0.3 coir fibre, 0.3 Jute fibre and 0.7 coir fibre and 0.5 Jute fibre and 0.5 coir fibre.

Synthetic polymers generally used for repair of concrete are harmful to the environment. Hence, the use of alternative repair techniques for concrete is being investigated. Calcium carbonate-precipitating bacteria can be used to plug the pores and impart a self-healing capacity to the concrete. However, these bacteria require specific conditions to survive. The environment inside concrete has a pH of 10.2–13.3 and an internal temperature that can go up to as high as 45 °C due to the exothermic nature of the hydration reactions. This study investigates the microbial growth as colony formation inside the hydrated cement paste to check the survival characteristics in these severe conditions. A direct technique of streaking to grow microorganism in a cement paste plate is used to check that, the cement paste has enough nutrients to support this growth. In this study, different species from same genus Bacillus, Bacillus cereus, Bacillus licheniformis bacteria are taken for comparative study along with Bacillus subtilis. From the current study, it was found that bacterial growth is clearly visible with 1% yeast extract. Also, from the SEM-EDS analysis calcium carbonate precipitation is evident. Further study can be performed to investigate the cell viability in cement paste as an extension of this work.

This paper describes an investigation on a new sustainable building block in cooperating waste materials namely, rice husk ash (RHA), fly ash, crushed glass, aggregates bound with bitumen as the binder. The bitublocks were prepared using four different mixes and its properties such as compressive strength, volume stability, the initial rate of suction (IRS), density, etc. were determined. It shows that all these properties are dependent on the type of aggregates and bitumen used as well as on compaction and the temperature at the time of mixing. In the UK similar experiments were done but the mixes used were different. Our results show that the properties of bitublock units are approximately similar to masonry building blocks available in India and it can be used in non-structural walls such as partition walls etc.

Masonry is the oldest method of construction and is composed of masonry units and mortar. The traditional masonry units like burnt bricks and conventional cement blocks are not considered as sustainable. Burnt brick consumes fossil fuel and top fertile soil. Hence there is a need to develop and use alternatives to traditional masonry units. Geopolymer technology is one among many alternatives in which complete elimination of cement is achieved without compromising the strength and durability. This technique makes use of supplementary cementitious materials like fly ash, Ground granulated blast furnace slag, etc. as binders [1]. The objective of this project is to study the effect of fly ash and alccofine on the physical and mechanical properties of geopolymer masonry bricks at different replacement levels of fly ash with 0, 10, 20, 30, 40% of alccofine and comparing the optimum results with fly ash brick [2, 3]. The polymerization is done with the help of alkaline activators. Sodium silicate and sodium hydroxide are the alkaline activators used. It is proposed to study the properties such as compressive strength, water absorption, density etc. and these properties are compared with that of that of fly ash bricks [4, 5].

Considering the increasing demand for sustainable and environment friendly construction materials, the feasibility of fly ash based alkali activated geopolymer bricks, has been aimed in this project as an alternative to ordinary bricks. Geopolymers are amorphous to semi crystalline alumina silicate polymer originated by inorganic polycondensation reaction of solid alumina silicate with highly concentrated alkali hydroxide or silicate solution. Production of building materials, particularly bricks using fly ash is considered to be one of the solutions to the ever increasing fly ash disposal problems in the country. Fly ash based geopolymer with alkali liquid to binder ratio as 0.4 and sodium silicate to sodium hydroxide ratio as 2.5 was studied in this project. Geopolymer bricks of size 230 mm × 110 mm × 70 mm were optimized by varying the molarity of NaOH, percentage of extra water added, curing conditions. The compressive strengths, water absorption and durability of optimized fly ash based geopolymer bricks were compared with cement bricks and country burnt bricks. Considering the economical aspect, the mix proportions were changed with fly ash to fine aggregate ratio as 1:6 and molarity of NaOH as 5M. Fine aggregate as river sand, M sand and quarry dust were also studied to find the most affordable brick.

The prominent issue in the construction business is the ecological and environmental contamination. In the construction industry, for the most part the generation of Portland cement causes the discharge of pollutants resulting in environmental contamination. We can lessen such consequences for nature by expanding the utilization of modern alternatives in our infrastructure development process. Geo-polymer concrete is one such substitute and is in effect progressively utilized on-site. To create the geo-polymer, concrete the Portland cement is completely replaced with the F-type fly-ash and alkaline fluids are utilized for the binding of materials. The alkaline liquids utilized in this examination for the polymerization are the solution of Sodium Hydroxide (NaOH) and Sodium Silicate (Na2SiO3). The cube samples taken are of size 100 mm × 100 mm × 100 mm for compression test, sorptivity test, carbonation depth test and 100 mm diameter × 200 mm height of cylinder are casted for splitting tensile strength and kept under acidic and saline conditions. The results are henceforth compared with conventional concrete of the same grade.

The amount of construction waste has been dramatically increased in the last decade, and social and environmental concerns on the recycling of the waste have consequently been increased. Waste concrete is one of the crucial among the construction wastes. Recent technology has also improved the recycling process. In this modern industrialized world, recycling construction material plays an important role to preserve the natural resources. Recycled aggregates can be used for cost reduction of the constructional project. In this research work concrete waste from demolished structure has been collected and recycled coarse aggregate (RCA) of different percentage is used for preparing fresh concrete. This study aims to evaluate physical properties of concrete having different proportion of RCA. Mechanical properties such as compressive strength and split tensile strength was determined for various replacement percentages of recycled aggregates. The results obtained are compared with conventional concrete of the same grade.

Masonry is one of the commonly used construction technology both in urban and rural areas. In this paper the in-plane behaviour of masonry walls is analytically studied considering existing closed form equations. Previous studies have proven that the lateral load behaviour mainly depends on the aspect ratios (h/L) as well as the axial loads. From this analysis the governing failure is determined and the lateral load versus lateral deflection curve is plotted for various percentages of axial loads. This graph gives the ductility of the wall. This concept is further applied to a simple masonry structure and the push over curve is plotted.

Concrete-Filled Steel Tubes (CFSTs) are composite members consisting of steel tube filled with concrete. One of the main advantages of CFST is that the interaction between steel tube and concrete will increase load carrying capacity of the specimen. The local buckling of steel tube is delayed by restraint of concrete and strength of concrete is increased by confining effect provided by steel tube. Steel tubes in CFSTs are exposed to environmental deterioration. In the present study, this disadvantage is overcome by modifying CFST as steel tube embedded in concrete. The modified specimen showed better compressive strength but the bond strength was reduced. Further modification was made by providing holes in steel tube and embedding it in concrete. This improved the bond strength of specimen due to better bonding between inner and outer concrete and the compressive strength reduced due to reduction of steel section. To improve strength the specimen was modified as windowed steel tube embedded in concrete. The resulting specimen had better compressive strength and bond strength. In this paper standard size specimens are modelled and analyzed for compressive strength and bond strength by varying steel tube thickness and an optimum configuration of windowed steel section is obtained.

Recent earthquakes have shown that steel moment frame (SMF) with weld connections are so brittle. According to the studies conducted, great damages are due to the cracking of the weld between the beam flange and the column face and inducing concentrated stresses in this area. A natural way to solve the problem is to reduce the ductility demand on the welded areas by reducing the stress concentration level. A useful approach to reduce the stress concentration at the panel zone could be the use of reduced beam section (RBS). A portions of the beam flanges are trimmed away in the region adjacent to the beam-to-column connection (Han et al. in J Constr Steel Res 70:256–263, 2012) [1]. The RBS can be viewed as a ductile fuse that forces the formation of the plastic hinge away from the joint so that much of ductility demand on beams may result from the RBS instead of the welded beam-to-column interface. RBS connection is widely investigated and used in US, Japan and Europe. In this study moment connections with different shape of reducing beam flange have been modeled using ANSYS and compared with each other during cyclic behavior. The sloped moment connection with best configuration is analyzed to find the cyclic response of the connection (Shen et al. in Eng Struct 22:968–983, 2000) [2].

The Finite Element Method (FEM) is the most widely used numerical technique to predict the approximate response of a structure under various loading conditions. Predicting the response of a structure to seismic loading using FEM can be computationally intensive and time-consuming. Parallel FEM is one solution to such situations where the computation is distributed efficiently among multiple cores available in modern supercomputers. In order to utilise the advantage of parallel computing in FEM, Pacific Earthquake Engineering Research Centre (PEER), has developed the open source software, OpenSees, with advanced capabilities for performing parallel FEM specifically for carrying out earthquake engineering simulations. In this paper, a new methodology is proposed to improve the efficiency of parallel computation using greedy algorithm in OpenSees for the time history analysis of framed structures for multiple earthquakes. Greedy algorithm finds an optimal solution in a number of steps by effective scheduling and proper load balancing. This method is verified by studying the time required for analysis of arbitrary framed structures using a high performance computing machine with a 32-core CPU, 62-GB RAM and 256-GB memory. A percentage increase of 16.35 is observed in the speedup factor for a two dimensional model studied.

Polyurethane Cement Composite (PUC) is an emerging material, versatile of all polymers. The stress-strain curve of PUC shows that it is equally strong in tension and compression and is an elastic material. It can be used for retrofitting purposes due to their excellent strength properties, light weight and ease of application. PUC also exhibit great ductility and durability properties due to the formation of dense microstructure. It has the combined properties of polyurethane and Portland cement. There is no need for adhesives as it excellent bonding characteristics. The only practical application was in the strengthening of T-Beam Bridge in Harbin, China (2016). The possibility of PUC as a retrofitting technique has not been explored yet. In this paper the static and dynamic response of the structure retrofitted using PUC, due to seismic loading is analyzed using finite element method. The finite element model is created in ANSYS software. The response of RC frame and RC frame strengthened using PUC composite and CFRP are also compared.

Steel-concrete-steel (SCS) shear wall consist of two steel face plates and a sandwiched concrete core which are bonded together by mechanical shear connectors to form an integral unit to resist external loads. The steel face plates were connected together using tie rods and to the infill concrete using headed studs respectively. The advantages of the SCS Sandwich structure over the traditional reinforced concrete are that the external steel skin plates act as the permanent formwork and flexural reinforcement and offer water proofing protections. This paper presents a robust finite element model developed in ANSYS Workbench for Nonlinear cyclic analysis of the SCS walls. Rectangular SCS shear walls with an aspect ratio of 1.0 were modeled and analysed under displacement-controlled, in-plane cyclic loading. A parametric study was carried out to investigate the effects of different shear connector configurations and push over analysis was performed to determine the best connector configuration. A new structural topology has been introduced for better performance.

Steel frames with column and beam connections welded together show brittle nature during earthquakes. According to previous researches, the major damages were the cracks developed in the welded portion between the beam flange and the face of the column. Such cracking results in accumulation of unwanted stresses in the welded region. Reduced Beam Section (RBS) method is an effective way to limit the accumulation of stress in the vicinity of beam column joint. Out of different advanced beam to column design approaches developed after the earthquakes in Northridge in 1994 and Kobe in 1995, the reduced beam section connection has proven satisfactory ductility levels in numerous tests. The use of RBS in beams to column connections results in the formation of plastic deformations at a certain distance from the beam column joint. In the present study new types of reduced beam sections have been modeled using ANSYS 16 software by trimming the beam flange in different pattern and is compared each other under cyclic behavior. The results obtained from this study have shown that the reduced beam section with same holes dissipates more energy than other type of connections.

One of the main causes of reinforced concrete degradation is chloride-induced corrosion. Chloride-induced corrosion depends on many factors like properties of the material, loading on the structure and environmental condition. There is much research on the deterioration of concrete structures over the years; but there is relatively little research on changing climate affecting the deterioration, which is the topic of this paper. The present study is purely analytical wherein conceptual T-Beam bridge girder has been taken for the prediction of time to corrosion initiation and corrosion propagation, incorporating effect of climatic condition. For comparison, eight study locations are selected. Corrosion initiation time is predicted for each location considering the climatic data of the corresponding location. With the variation in the temperature and relative humidity data at different study location, large variation in corrosion initiation time is found.

Cracking of reinforced concrete flexural members is a highly random phenomenon. The evaluation of cracking resistance of a reinforced concrete structural element is important from a view point of its performance in limit state of serviceability i.e., in cracking. Deterministic analysis of cracking moment for all the beams is carried out. Probabilistic analysis of cracking from different cross sections of RC T-beam bridge girders is performed. For this purpose, different cross sections of RC T-beam bridge girders designed according to MORTH for seven spans namely 10, 12, 14, 16, 18, 21 and 24 m are considered. Probability of cracking of each cross sections of beam is determined using relative frequency approach within the framework of Monte Carlo Simulation. With respect to the distribution of basic variables considered in this study, cracking moment of RC T-beam is found to follow lognormal distribution. The probability of failure against cracking is found to be very high. Cracking moment is found to be independent of load combinations adopted in the study. The present article can be used as a reference for examining the beams for limit state of cracking.

Recent roof construction includes introduction of openings which is the intentional acceptance of ambient air into a space and it can also be used for purposes of thermal comfort or dehumidification. Choice of roof depends upon the architectural criteria as well as purpose of structure. Nowadays structure having large spans requires openings for various purposes. Providing openings can create both internal and external pressures which will require detailed analysis. Wind-induced internal and external pressures can be investigated by using a full-scale wind testing facility generically known as Wall of Wind (WOW), Wind tunnel experiments, rain flow count method and tornado vortex simulator. This paper reviews the test to be conducted, parameters to be considered for wind analysis of roofs with openings.

Steel-concrete composite girders are widely used in the construction of bridges and buildings. However when they are provided in continuous spans, a loss of strength and composite action will be occurring at the hogging moment region due to the development of tension in concrete and compression in steel. Limited works have been done to study this shortcoming in these widely used girders. Carbon fiber reinforced polymer (CFRP), is found to have lot of untapped potential for improving the strength of girders. This paper presents an analytical investigation into the behavior of composite girders strengthened in hogging moment region using CFRP. Effect of different arrangements and thickness of CFRP laminates are also being compared for different geometries. CFRP was found effectively improve the strength of composite girders in the negative moment regions especially when used in the form of strips.

A new class of materials, laminated composites is increasingly being used for a wide range of civil infrastructure applications and aerospace structures due to their high strength, stiffness, lightweight and durability. It is generally assumed in bending theory that plane sections remain plane after loading, this assumption does not hold for box beams with wide flanges. Shear lag effect can bring non uniform normal stress distribution on flanges; it would affect the strength design of thin-walled beams. The strength of thin walled members is governed by the buckling criterion. In this paper effect of shear lag on buckling behavior of laminated composites is examined. The present study investigates about analysis of hat shaped box beam model for buckling behavior and approach for finding out the shear lag effects on symmetrically laminated graphite epoxy thin walled composite box beams under flexural loading. A parametric study has been carried out using the homogeneous and orthotropic finite element models created by ANSYS16. Influences of orthotropic parameter and cross sectional parameter are studied.

Failure of RC structure triggered by fracture is a much critical situation across various engineering disciplines. Progressive collapse, one of the most devastating type of building damage occurs when major structural load carrying member suddenly collapse due to accidental loads such as gas explosion, terrorist attack, fire, vehicle impact etc. Such accidents may occur at any floor and at any location. If neighboring members are not capable to resist and redistribute the additional load received, that part of the structure fails. This misbehavior of structure leads to costly damage, multiple injuries and possible loss of life. RC structure can resist progressive collapse through various mechanism such as Catenary action and Vierendeel action. The span length and beam depth required to satisfy the failure criteria for progressive collapse was obtained by using the virtual work method, as there is an equilibrium of the external work done by gravity load due to loss of column and the internal work done by plastic rotation of beam. The main focus of this paper is to assess the effect of location and span of RC building with an aspect ratio 1. In order to explain the behavior of structure elements, non-linear dynamic analysis was done using finite element software as per GSA and UFC-DoD guidelines. It was found that damage to corner column cause more torsional vibration compared to other cases.

A parametric study was carried out to investigate the structural behavior of reinforced concrete T beams under different external prestressing conditions. This paper adopted two external prestressing methods; to study and to compare the behaviour of externally prestressed tendons that is, 12 mm diameter steel bars and 12.7 mm steel strands by strengthening T-shaped reinforced concrete (RC) beams which is subjected to static loads. The influences of concrete strength, reinforcement ratio of the non-prestressed tensile steel bars and prestressing force on the these tendons in terms of ultimate load and load deformation were examined. The test results revealed that, compared with unstrengthened RC beams, the specimens externally strengthened with prestressed steel bars or steel strands showed a better performance in load carrying capacity. After that the better prestressing method was modelled and validated by finite element software ANSYS. It can provide a reference for the further promotion of the structure.

Objective of the present paper is to present the results obtained utilizing visco-elastic analysis with commercially available software such as FEASTSMT and MARC. FEASTSMT is a structural analysis software being developed at VSSC and marketed. Viscoelastic analysis capability is being regularly used in rocket industry for structural integrity analysis of solid propellant rocket motors. The finite elements required for such analysis are plane-strain, axi-symmetric and three dimensional solid elements. In this paper plane strain configuration is considered for the study with pressure, gravity and thermal loading. Results obtained with the two software are compared in terms of displacement and number of time steps required for the convergence of the exact solution where ever possible. From the study it is found that there are some mismatches in different softwares, in final answers and also the way in which it converges to the solution. The variation of results are presented in the paper.

Reinforced Concrete (RC) special shear wall is widely used in the lateral load resisting system of multistoried buildings due to its large in-plane lateral strength and lateral stiffness. In the present study, the influence of enlarged boundary elements on the possible seismic behaviour of such shear wall is studied. Detailed finite element modelling of a slender RC shear wall is carried out with enlarged boundary elements. 8-noded solid elements and 2-noded truss elements are used for modelling the concrete and the reinforcement parts, respectively. Material nonlinearity is considered by assigning damaged plasticity model properties to concrete and bilinear strain-hardening constitutive model to reinforcement, respectively. For obtaining the effectiveness of the enlarged boundary elements, another shear wall with rectangular cross-section is modelled considering the total plan area to be the same for both the wall sections. Nonlinear static analysis is carried out for both the models under varying axial compression. Based on the lateral load-deformation response, strain distribution profiles and damage characteristics, the wall section with enlarged boundary elements is observed to have better peak flexural capacity and the lateral drift level at the instant of peak flexural capacity as compared to the rectangular wall.

Reinforced Concrete (RC) special shear walls are provided in the lateral load resisting system of multistoried buildings to improve the overall seismic performance of those buildings. For any RC wall section, the actual flexural capacity (M) is significantly influenced by the level of axial force (P), and the same is represented by the P-M interaction diagram. In the present study, finite element modelling is carried out for an isolated slender wall with enlarged boundary elements at its ends. 8-noded solid elements and 2-noded truss elements are used for modelling the concrete and the reinforcement parts, respectively. Material nonlinearity is considered by assigning damaged plasticity model properties to concrete and bilinear strain-hardening constitutive model to reinforcement, respectively. The effect of confinement in concrete is considered. The model is subjected to pushover analysis under varying levels of axial compression. The strain distribution profiles are noted to identify the four possible failure modes namely, (a) cracking of cover concrete, (b) spalling of cover concrete, (c) crushing of core concrete and (d) yielding of vertical reinforcement in boundary elements. The flexural capacities, observed for different failure levels, are compared with those obtained from the actual P-M interaction diagrams.

Offshore structures and vessels have the helideck platforms for facilitating helicopter landing as well as take-off phases. The weight reduction for a specific well-known design without altering its main dimensions offers best possible alternative for the sake of economy. Reducing the structural weight of helideck is the best way possible alternative for the sake of economy. Optimising the structural weight is of paramount importance in marine applications. Hence, it becomes necessary to focus on the response of the structure using finite element analysis. From the FEA results the structure can be optimized so as to reduce the weight of the structure. The structure is analysed for normal and emergency landing of helicopter at and for two materials, Steel AH36 and Aluminium alloy of grade 5083-H116. Also, the structure is analysed for different scantling of secondary stiffener. The results are documented and compared so as to obtain an optimised design for the structure.

Importance of fiber reinforced polymer (FRP) strengthened technique is significant in the case of reinforced concrete slabs. Even though a wide variety of FRP strengthening technique is available, but premature debonding is the main failure model in ordinary bond technique, and the strengthening effect is limited. The present study concentrated on hybrid bonded FRP strengthen technique and it is a combination of externally adhered and mechanically fastened fiber reinforced polymer system. This study focused on finite element analysis by using ANSYS and compare the structural behavior of externally bonded (EB) and hybrid bonded (HB) FRP strengthening systems.

Earthquake forces and hydrodynamic pressure are important parameters to be considered in the design of water tanks. In this study, response of ground supported cylindrical water tanks were studied under static and harmonic loading at different water heights and different aspect ratios using finite element software ANSYS. The main objective is to determine the influence of soil structure interaction on dynamic response of water tanks. Soil is modelled as three layers consist of clayey gravel, silty sand and hard rock. It is concluded that, soil structure interaction amplify response of water tanks under static and harmonic loading.

A Self Centering Moment Resisting Frame (SCMRF), an alternative to a conventional Moment Resisting frame, is characterized by gap opening and closing at the beam-column interface under earthquake loading. The beams are post tensioned to columns by high strength post tensioning (PT) strands oriented horizontally to provide self-centering forces when gap opening occurs. A Self Centering Moment Resisting Frame for earthquake resistant structures has the attributes of ductility, requires no field welding and returns the structure to its pre earthquake position which prevents permanent deformations when subjected to seismic loading. Energy dissipation is provided by supplemental elements that deform under the gap opening behavior. Unlike special steel moment resisting frame with welded connections a SCMRF can be designed to survive earthquake without much structural damage which provide immediate occupancy performance. Nonlinear static analysis is performed in ANSYS to investigate the effect of posttension load and bracing configuration on seismic performance of frame. The results indicated that an increase in PT force increases the residual drift and maximum load carrying capacity. Bracing in SCMRF is effective in increasing the load bearing capacity and energy dissipation. Bracing shifts the maximum stress position from beam column connection to gusset plate so that it act as sacrificial element which can easily be replaced without damaging the beams or columns.

Today steel is the most useful building material in the construction field. Steel structures tend to be more economical than concrete structures for tall and large span buildings and bridges due to its large strength to weight ratio. The steel structures in the areas of high seismic activity should be stiff enough to prevent structural damage and have sufficient ductility to prevent collapse. Incidentally, steel bracing provides an effective and economical solution for resisting lateral forces in a framed structure. Among the bracings, Knee braced steel frame has got excellent ductility and lateral stiffness. Since the knee element properly fuses, yielding occurs only on knee element leaving the structural elements safe. In this paper, a study on the seismic effect of knee braced steel frames of different configurations were performed and compared with Y shaped Eccentric bracings, having a vertical shear link. Performance of the frames were studied using non-linear static analysis and non-linear time history analysis for various influencing factors.

Hybrid coupled walls (HCWs) are comprised of two or more reinforced concrete wall piers connected with steel coupling beams distributed over the height of the structure. Extensive research over the past several decades suggests that such systems are well suited in regions of high seismic risk. Steel coupling beams in a hybrid coupled shear wall provide a viable alternative for concrete coupling beams coupling individual reinforced concrete wall piers [1]. In such a system, coupling beams are designed to undergo inelastic deformation and dissipate seismic energy by means of capacity design principles. The coupling beam is installed with a steel plate with slits which acts as the sacrificing element. The study takes into account different slit configurations. Based on non-linear static and cyclic analysis the behaviour of coupling beams under different configuration is assessed and the best slit configuration is optimised. Time history analysis is carried out on the HCW model with the best slit configuration in ANSYS and compared with the conventional one. Thus the study proposes a new configuration of coupling beams with slits, which endows the coupling beam with damage controllability, a large capacity to consume energy, and a design flexibility regarding stiffness and strength.

Hill towns of India are vulnerable to different types of natural hazards, which may cause enormous destruction during their occurrence. It leads to substantial loss of precious human life and resources. In this study, two different configurations of buildings have been modeled and analyzed using ETABS 2016 software. The building can be made strong to resist lateral loads by adding bracings or shear wall to the structure. A parametric study has been carried out, in which the buildings are geometrically varied with different bracing and shear wall configuration. All analytical models have been subjected to seismic forces along and across hill slope direction and analyzed by using Time History Analysis. Various building configurations including combination of shear wall and bracings were considered and their behavior in terms of maximum storey displacements, storey drifts and base shear in buildings were discussed. After studying the behavior of buildings on slopes, notable increase in seismic performance is obtained on combined configurations using both bracings and shear walls.

Electricity is one of the most important necessity of any growing economy. The transmission tower line system consisting of transmission towers and conductors are the main element of an electrical system. Failure of this system leads to greater economic loss. However most of the researches are concentrated on static load, impulsive load and wind loads but not on seismic effects of the system. This study mainly focuses on the seismic behaviour of the combined system of transmission towers and conductors. The model is created based on Indian standard codes. A three tower model connected by cables are used for analysis as they give more realistic results than a single tower model. Four basic towers 66, 132, 220 and 400 kV are created in SAP2000 and time history analysis is conducted on these models to study their seismic behaviour. Analysis is also conducted to find out their behaviour under critical conditions of seismic loading.

A large number of vertically irregular buildings exist in modern urban infrastructures, and so the area of vertically irregular type of building is now having a lot of interest. When such buildings are located in a high seismic zone, the structural engineer’s role becomes more challenging and consideration of lateral load is very much important. Recently the diagrid structural system is widely used as lateral load resisting system due to its structural efficiency and aesthetic potential provided by the unique geometric configuration of the system. This paper presents a brief study about diagrids on a geometrically irregular structure. For this particular study a building with base dimension 36 m × 36 m and 129.6 m height is taken and vertical geometric irregularity is given to the base structure. Each storey height is 3.6 m. Diagrid with uniform angle throughout the height is provided as lateral load resisting system. Time history analysis is done using ETABS 2016. Seismic performance of geometrically irregular building provided with diagrids is studied by varying diagrid angles. The results in terms of maximum storey displacement, maximum storey drift, time period, structural weights and base shear are compared.

Seismic isolation is a well-known seismic strengthening method and mid-storey isolation, which is providing isolation at middle stories, is one among those techniques. Mid-storey isolation is a less explored strengthening measure compared to the popular base isolation method. It has many advantages over the base isolation in terms of construction efficiency, cost, space use, maintenance, etc. Since buildings with discontinuities are more prone to serious damage or failure during earthquakes due to their weak points, study on the effect of these isolation techniques on irregular buildings is relevant. This paper presents the time-history analysis of a regular and a stiffness irregular G+20 storey building and their seismic responses when incorporated with isolators at intermediate stories rather than at the base. The structural analysis software SAP2000 has been used for the analysis process. Storey shear, storey drift and acceleration of these high rise structures are plotted in comparison with that of fixed base.

The building structures are vulnerable to severe damage and collapse due to strong ground motion. Among the various structural damages, pounding damage is the most serious one. This is the most serious seismic hazard usually occur in highly populated areas during earthquake. Pounding is mainly observed when there is insufficient gap between the adjacent buildings. This scenario mainly is in urban areas where multi-storey buildings are closely occupied due to non-availability of sufficient land or may due to high land value. The adjacent buildings with insufficient gap may collide each other under strong ground motion which results in the damage of the structure. Hence, it is necessary to study of the effect of pounding on buildings. Here, the dynamic analysis of the effect of pounding on building is studied using the software SAP 2000. Two adjacent RC frame structures are considered for the analysis. The building structure is modelled and analyzed for pounding and without pounding case. Non-linear time history method of dynamic analysis has been used in this study. Later the effect of shear wall and cross braces on seismic pounding is studied. The parameters considered for the study are storey displacement and drift. This study mainly focuses on the effect of mitigation techniques on pounding to determine the efficient method for minimizing the damages under seismic effect.

In India, the structures are not usually designed for extreme loading conditions and when they subjected to such load conditions, it can be led to catastrophic failure. Recently, terrorist attacks target our important building such as school buildings, shopping complex, government offices etc. led to their structural failure. Structure all over the world is exposed to terrorist attacks. According to the National Bomb data center, India had the highest bomb blast in the world in the past two years. Blast resistant design of the structure is uneconomical and it involves tedious calculations. But the seismic design of the building is a part of the conventional design. If the dynamic response of the building meets the requirements then we can avoid the complex calculations associated with the blast-resistant design and we can obtain an economical section. In this study, the column was analysed using the high fidelity physics based finite element code, LS DYNA.

Today new technique of construction as well as aspect of design is coming to forefront as method of conventional design has failed to give the proper result. Base isolation is one of the most widely accepted seismic protection system used in earthquake prone areas. The base isolation system separates the structure from its foundation and primary moves it relate to that of the super structure. Diagrid structure is new trending concept in the field of structural engineering taking into account the factors of structural stability, aesthetic appearance and economic consideration. The scope of the paper is related to the seismic analysis of steel diagrid structure in combination with base isolation. Here Triple Friction Pendulum Isolator is used for base isolation. Dynamic linear response spectrum analysis and dynamic linear time history analysis is performed in the isolated diagrid building. Further a comparative study of performance of base isolated diagrid building has been carried out by response spectrum and time history analysis by changing the bracings and bracing arrangement pattern. i.e., X, V, inverted V, eccen forward and eccen backward bracings in whole, alternate, horizontal and vertical pattern arrangements. For this a 22 storey and 11 storey steel diagrid building is designed and the above mentioned analysis is carried out. Base shear and top storey displacement are used as parameters for this study. From the results it concluded that for both 22 storey and 11 storey diagrid building, building having V bracing with alternate arrangement pattern showing better results.

Earthquake, its occurrence and effects, its impact and structural response have been studied for many years in earthquake history and is well documented. The structural engineers have tried to examine the various method, with an aim to determine the complex dynamic effect of seismically induced forces in structures, for designing of earthquake resistant structures in a advanced and easy manner. From the study conducted it was found that more precise results are found from nonlinear static analysis method. An overview of the past researches conducted on the modelling of masonry infilled frame issues, it was found that macro model which consider the effect of masonry weak links is used for modelling the infill panels. Different factors governing the period of vibration was checked, and the result shows the effect of stiffness of the building is the most important factor influencing the period of vibration. Parametric study was conducted to determine the most influential factor that affects the period of vibration of a structure. From the observations it was clear that the effect of stiffness is the most important factor influencing the period of vibration. Therefore a curve with dimensionless height and lateral displacement were plotted using nonlinear static analysis obtained from SAP2000. From the above mentioned curve, the effective stiffness of the building under consideration is calculated, which route to find the period of vibration of the structure that is considered for the seismic analysis [1].

Construction industry has accomplished extensive growth worldwide particularly in past few years. For a project to be successful, safety of the structure as well as that of the workers is of great importance. Safety issues are to be considered from the planning stage to the completion of the structure. Construction industry employs both skilled and unskilled labour subjected to accidents and risks. The number of fatal accidents taking place at the construction sites is quite increasing. According to a recent study by the International Labour Organization (ILO) 165 out of every 1000 workers have faced injuries from the job. From the results of Occupational Safety and Health Administration examination, the causes of construction fatalities, it was shown that 39% of fatalities in construction were caused by falls, 8.4% were struck by objects, 1.4% were caught in between incidents, and 8.5% were caused by electrocution. Very little research has been done on the occupational health, hazards and psycho-social problems of workers especially in different countries like India. Safety in construction is important as any fatal accident will cause irreparable loss of human life, money and progress of work leading to reduction in morale and demotivation of work force. A psychosocial hazard is an occupational hazard that affect the psychological as well as the social well-being of workers, including their ability to participate in a work environment among other people. Exposure to psychosocial hazards in the workplace produces both psychological and physiological damage to the employees. It also produces repercussions within the society, thereby reducing the productivity in local/state economies, corroding familial/interpersonal relationships, and producing negative behavioural outcomes. In this study, we would like to conduct a questionnaire survey across Kerala construction industry and analyse the result using AMOS 22.0 to evaluate the reasons behind accidents in Kerala construction industry.

5S is an essential tool in lean assembling frameworks. It is a tool for cleaning, arranging, sorting out and giving the vital basis to work place quality enhancement. This methodology can manage the space, human effort, time, quality and capital to make the end product with minimum faults and make the site as well ordered, disciplined and clean place to work. 5S application improves personal standards and motivation of workers in their workplace and has a high impact on work area, safety, quality, and efficiency. Efficient material management is essential in managing a productive site. The purpose of this paper is to study the principle of 5S methodology for identification of waste in construction organization to improve the labor productivity, safety and quality of works on residential building sites. This project intends to create a framework for 5S audits for construction sites to assess the current condition and also the conformity towards 5S.

In a construction project, materials account for more than 40% of the total project cost. A small saving in material cost through efficient control of materials can result to a large saving in the total project cost. Most organizations face challenges of overstocking of materials, duplication, and resource wastage. The difficulty is to acquire approaches that would enable minimization of such wastages and losses to improve on materials control performance. The objective of this study is to find the benefits of the material control techniques by improving quality and minimization of cost on effective material variety. The material data’s are collected from various sites which is then quantified, measured and analyze through material control techniques thereby constraints of material productivity can be found out. For this purpose material requirement planning techniques such as DOQ, EOQ and PPB methods are used. Then it is compared with conventional method. The study helps in reducing total material cost and there by reduction of total project cost.

Construction Industry plays an important role in socio-economy development of any developing country. Construction time serves as a benchmark for assessing the performance of any project. Unexpected problems encountered during construction phase causes unwanted delays in project completion. Construction delays can be defined as the late completion of work compared to the planned schedule or contract schedule. It can be minimized only when their causes are identified and suitable preventive measures are adopted. The objective of this paper is to identify the factors affecting delays in a construction project and presents the initial stages of development of a software to predict the possible delays.

Ready mix concrete is an advancement over the old site mix concrete and is preferred due to its flexibility, time, quality, cost effectiveness etc. Ready mix concrete is transported from plant to site using transit mixers and volumetric mixers. Among which transit mixers are widely used now-a-days. Productivity of mixers therefore contributes towards the success of ready-mix concrete plant and construction site. Productivity of transit mixers depends on the cycle time involved during the process of concrete delivery. So it is necessary to identify and quantify those factors to minimize the cycle time and to increase productivity. This paper deals with the identification of factors affecting cycle time of transit mixers and analyzing the impact of these factors on productivity. Hauling time and time for transit mixer weighment were found to be the major factors that affect the productivity.

“When will the project performance indices in my project become stable?” is an ever interesting fundamental question in earned value management (EVM) but mostly unresolved as well, especially for the highly dynamic construction projects which call for frequent updating and rescheduling. The stability of the performance indices assures the credibility of EVM as an effective tool to analyse the project performances as well as to forecast the requirements. This paper presents an assessment of time and cost performance stability in EVM based on an analytical stability simulation model which evaluates the probability of the stable project performance indices during the project execution for topologically diverse construction project networks. The model is used to identify the effects of percentage completion, network topology as well as its compounding effects on the stability of EVM forecasting and topology–stability relations were developed for schedule performances. Finally, the performance indices are compared for the stability behaviour.

Agile Project Management is an iterative approach to planning and guiding project processes. It is suited for large complex projects where it is difficult to specify the product in advance. This thesis has focused on what opportunities there might be in implementing the Agile project management approach on the basis of Scrumban method in the residential building construction. The major advantages found with implementing the Scrumban approach is an improve productivity and resource allocation. The Scrumban approach almost forces the client to increase their participation in the project compared to the situation today. By the use of time management and specific meetings it will also be beneficial for keeping track of the project’s progression and status. This project intends to create a methodology for improvement of residential building construction by Agile management software.

Aggregate quality influences concrete mix design and properties. It is necessary to measure the quality of aggregate. The most popular field test to measure the quality of aggregate is the sieve test. It is not possible to measure shape characteristic and other parameters by sieve analysis. Therefore, it is essential to develop rapid assessment techniques for quality control of aggregate. Selection of methodology for aggregate shape characteristic measurement depends on parameters such as aggregate size, accuracy, reliability of the method, time required to analyze the sample, human efforts required, measurement of other characteristics of the particle apart from the size, the robustness of testing equipment, the initial cost of the equipment, its maintenance and operational costs. Digital image analysis is a process to gather information regarding a characteristic of particle through computer programming. Digital image analysis method has a potential to estimate the characteristics namely, the size and shape of aggregates rapidly and accurately. Two-dimensional image analysis of aggregate gives a relative idea of aggregate properties in a more accurate manner as compared to the procedure suggested in Indian standards. This paper summarizes the developments and research in the area of image analysis.

In most of developed and developing countries, masonry is still widely used for building construction. Unreinforced masonry walls (URM) are widely used all around India. Seismic forces have a large impact on buildings. Masonry walls are more vulnerable during earthquakes. Hence there is a necessity to find solutions to strengthen URM walls. Application of steel wire mesh and mortar is one of the commonly used techniques for seismic retrofitting of such buildings. URM walls include those made of clay bricks, concrete blocks, hollow bricks etc. The effect of strengthening on in-plane shear behaviour of URM walls, including failure modes, shear strength and ductility are investigated. The panels are subjected to in-plane diagonal tensile test. Test is done according to ASTM E519-02. The present study investigates the effect of welded wire mesh and mortar on shear strength parameters of masonry wall panels. Four set samples of masonry wall panels made of locally available concrete blocks in kerala are selected and strengthened using varying spacing of wire mesh and hexagonal wire mesh. Shear strength parameters are clearly studied using bilinear idealization and adaptability of different wire meshes in strengthening of existing masonry walls is clearly investigated.

Deep beams are structural elements that can carry a significant amount of load to the supports by compression force as a combination of load and reactions. They are loaded as simple beams. Deep beams have large depth to thickness. Because of the geometry of deep beams, their behaviour is different with slender beam or intermediate beam. Shear failure is the most common mode of failure in deep beams. The shear failure mode occurs in the absence of flexural cracks. The shear behaviour of deep beams are very complex and there is still no agreement on the role of size effect in shear due to lack of information. Sudden failure due to low shear strength is not desirable mode of failure. The reinforced concrete beams are primarily designed for flexural strength and shear strength. Among various methods of shear enhancement, replacement of stirrups using steel plates is a new technique. Providing holes in these steel plates brings better bonding of concrete between the steel plates and it is expected that the shear strengthening of deep beams can be achieved and hence the load carrying capacity can be increased. This paper aims at finding the best suited thickness for steel plate having suitable configuration of holes so that maximum load carrying capacity can be attained.

Expanded polystyrene (EPS) is a lightweight material commonly used in engineering applications since 1950s. Lightweight concrete can be produced by replacing the normal aggregate with lightweight aggregate, either partially or fully, depending upon the requirements of density and strength. Expanded polystyrene waste replaces coarse aggregate to produce light weight non-structural concrete with unit weight varying from 950 to 2000 kg/m3. Metakaolin is a valuable supplementary cementitious material for concrete and cement applications. Usually 8–20% (by weight) of Ordinary Portland Cement is replaced by Metakaolin. In this study, various mixtures were produced by partially replacing varying percentages of coarse aggregates volume with EPS beads and substituting cement with varying percentage of Metakaolin and their properties were estimated through laboratory experimental study. Such a concrete exhibits appreciable engineering properties. The engineering properties like compressive strength, split tensile strength, density and water absorption of the expanded polystyrene-based lightweight concrete is compared with M30 grade conventional concrete. The obtained results were compared with standard ranges of lightweight concrete as specified in ACI Committee 213.

Construction and demolition waste represents both the largest waste stream as well as an increasingly utilized supply of material to the construction industry. On the other hand, it is now widely recognized and steadily accepted that there is a significant potential for reclaiming and recycling demolished debris for use in value-added applications to maximize environmental and possible economic benefits. Indeed, it is widely acknowledged that recycling of CDW for reuse as fine aggregate in new concrete production is technically viable and under certain circumstances environmentally sustainable and economically feasible route to convert this material in a valuable resource. To synthesis best performance Self Compacting Concrete (SCC), factors such as Super Plasticizer (SP), fly ash and fine recycled concrete aggregate (FRCA) are studied experimentally based on Taguchi analysis, keeping SCC efficiency as the response in MiniTab software. The fresh and hardened properties of SCC incorporating FRCA are investigated by the experimental study to evaluate the efficiency of SCC. Factors for optimum level were fixed by SN analysis using larger the better quality criteria. The analysis was evaluated for a confidence level of 95%. The most influencing factor and optimal level of factors for maximum efficiency are determined. Confirmation experiments were done for the optimal levels of factors and the predicted values were compared with the experimental values.

In fibre reinforced cementitious composites (FRCC) bonding between the fibres and matrix governs many important properties, which includes strengths, fracture energy, ductility, and energy absorption capacities. The study explores the application of a microbially induced calcite precipitation (MICP) to pre-treating surface of polypropylene (PP) fibres for enhancing the interfacial boning strength. The technique utilizes MICP process to produce calcium carbonate that binds onto the fibre surface, leading to increased interfacial bond area and strength. Laboratory tests indicate that MICP modification could increase the mechanical and durability properties of concrete. Tests on hardened concrete to analyse the mechanical properties was done as per IS 516-1959. A durability study was also done as per ASTM standards to analyse the behavior of the developed concrete under adverse weather conditions. Results acknowledged an important role of MICP pre-treatment in enhancing both the mechanical and durability performance of concrete.

Concrete plays an important role in construction industry. Over the last twenty five years, amazing progress were gained in the research and use of Ultra high performance concrete, as it can provide a durable and cost effective structures. High compressive and tensile strengths, high ductility, and toughness, high flow ability and durability are the outstanding mechanical properties of UHPC. Also, it resists all kinds of corrosion, resulting in maintenance-free constructions. UHPC shows very high brittleness due to its exceptionally high compressive strength and is considered as a weakness. However, UHPC has its drawbacks in terms of tensile strength and brittleness. Hence, these encourage the development of high strength and better performance concrete and create the need to research on the use of Carbon Nanotube (CNT) in UHPC. This is because CNT was believed to be able to further improve concrete’s mechanical properties due to its impressive characteristics. In this study, carbon nanotubes is added in different percentages (0.03, 0.06, 0.09, 0.12 and 0.15%) and finding optimum percentage which contributes maximum strength to the UHPC.

Concrete is the most widely used construction material. Micro cracks which occur on the concrete structures can reduce the strength of the structure. Prolonged exposure of these cracks to the stresses and external environment can increase the damage and can even be lethal. Bacterial concrete is a solution for the micro cracks. Bacterial concrete has a self healing property by which it can repair cracks upto 0.5 mm width. An investigation is conducted to study changes in the compressive strength, split tensile strength and flexural strength of concrete by the addition of bacteria. Concrete specimens with bacterial concentrations of 0, 15, 30 and 45 ml mixed with equal amount of calcium chloride are used. When crack occurs, and water passes through the cracks, the bacteria present in the concrete matrix starts to feed on the calcium chloride by consuming oxygen and converts the calcium chloride into the insoluble calcium carbonate (limestone). And this limestone heals the cracks. Durability of the bacterial concrete is also studied and compared with normal concrete by analyzing the water absorption and reaction to sulphate and chloride ions.

Self-Compacting Concrete (SCC) is a concrete mix having high flowability and resistance to segregation. It fills the framework and consolidates under its own weight without external vibration. SCC has a brittle nature, therefore to improve its tensile properties as well as the behavior under the impact, impregnation of different kinds of fibres can be adopted [1]. Reinforced SCC with polypropylene fibre has shown promisable result in both fresh and hardened state, addition of Hooked end steel fibres along with polypropylene fibre could enhance flexural residual strength, producing a hybrid fibre-reinforced SCC, which is well suited for structural use. Three volume ratios of steel fibres (0.5, 1.0, 1.5%) were mixed with three amounts (0.3, 0.6, 0.9%) of polypropylene fibres. Studies are carried out on the fresh and hardened properties of SCC for all the mixes. The fresh property tests such as Slump flow test, V-Funnel test, U-Box test and L-box test was conducted on the developed SCC to check the compatibility, filling ability, passing ability and segregation resistance. The hardened properties such as compressive strength, split tensile strength, flexural strength was determined by conducting suitable tests as per the European guidelines of SCC (EFNARC) and compared with that of standard specimen. From the experimental test results compressive strength of concretes did not change considerably, but the addition of fibres had noteworthy effects on splitting tensile and flexural strengths. As expected, the increase in fibre content led to an increase in these strengths. Fresh properties of SCC were found to decrease with an increase in fibre content.

Super plasticizers are chemical admixtures used where well-dispersed particle suspension is required. Its application in concrete facilitates the reduction of the water with respect to the cement ratio without adversely influencing the workability of the concrete sample. Nowadays, due to rapid constructions there is a huge demand for the use of chemical admixtures. Among these admixtures, super plasticizer poly carboxylic ether (PCE) and naphthalene formaldehyde sulphonate (SNF) has great market relevance. The optimum dosage of the admixture is to be determined and the percentage reduction of water content is also noted. Various tests are conducted on the sample at different mix proportion and at different age as per code specifications. Perlite, which is a type of amorphous volcanic glass, is replace with fine aggregate at optimum dosage of the super plasticizer and strength is determined [1]. Perlite addition will results in green concrete of superior strength, fire resistance, acoustic properties, thermal insulation, HVAC conditions along with the replacement of conventional materials used in concrete. This research investigates on the determination of optimum dosage of super plasticizer and possible replacement of fine aggregate with perlite for sustainable concrete.

Development of a nation is directly dependent on the available infrastructure. Due to the tremendous growth of infrastructure, demand for building materials such as river sand and cement is also increasing day by day. As the demand for river sand increases; large volume of sand is extracted from the rivers resulting in many adverse environmental effects as well as increase in cost. The cement production is also to be increased to meet these demands and this production has a very bad impact on environment due to CO2 emission. In order to reduce both these problems, an eco-friendly solution using sea sand and crushed sand as alternative fine aggregate in geopolymer concrete (GPC) is proposed. In this study, an M40 grade GPC with fly ash and Ground Granulated Blast Furnace Slag as binder and a combination of hydroxide and silicates of sodium is used as reaction liquid. Various tests like compression, flexure, split tension, water absorption, sorptivity and Rapid Chloride Permeability were carried out. It is found that, performance of GPC with sea sand and crushed sand are comparable or marginally higher than that of GPC made of river sand in terms of mechanical and durable properties.

Development in construction field is a matter of great importance in the present day scenario. To achieve all the infrastructural needs of present ever growing population, a large number of residential, commercial, industrial and transportation structures are to be constructed. The structural load acting on a building has to be safely transferred to the ground. But due to space constrain and lack of hard stratum, structures have to be constructed on the weak soil. This is a great challenge to civil engineers as there is a chance of settlement of foundation or failure of structured. Hence different ground improvement techniques have to be implemented to improve the property of soil. A variety of ground improvement techniques are available now a days, among them most widely used technique of reinforcing soil is with geosynthetic materials. Screw pine-cell is the most advanced form of Geocell. It is a three dimensional, natural, honeycomb like structure of cells interconnected at joints. The soil particles can be trapped inside these cells providing an overall confinement to the soil layer and improves its properties regarding support to civil engineering structures. In our study we focus on how to increase the load carrying capacity and reduce the settlement of weak soil using Screw pine-cells.

Cement is one of the most versatile construction material used worldwide. But cement industry is responsible for several environmental issues like global warming. To address these issues there is a need for alternative binders to substitute cement. Geopolymer concrete (cement less concrete) is found to be a better alternative to conventional concrete. Geopolymer concrete (GPC) utilizes the cementitious properties of industrial byproducts like flyash, silicafume, GGBS etc. Flyash based geopolymer concrete is the common type of GPC. Flyash based GPC requires heat curing and is suitable only for precast members. Development of GPC which does not require heat curing will widen its application. This work aims to study the effect of metakaolin on the properties of ambient cured flyash based GPC. Experimental investigation is carried out by replacing flyash by metakaolin in varying percentages of 20, 30, 40, 50 and 60%. It was observed that ambient cured flyash-metakaolin GPC possess characteristics suitable for structural applications. The mechanical properties of GPC increased with increase in metakaolin content while workability properties showed a slight reduction.

Bond durability of ribbed basalt fiber reinforced polymer bars and steel bars exposed to sulphuric acid environment for different durations was investigated. Seventy-two pull out specimens were tested under direct tensile load to study the bond performance in terms of their bond strength and bond failure modes. The test parameters included the bar material such as basalt and steel, the duration of exposure such as 28 and 56 days, grade of concrete such as M25, M30 and M35, and bar diameter such as 10, 12, 20 mm. Experimental results showed that the bond strength of BFRP bars to concrete decreased by 19% of that of steel bars. All the specimens failed by concrete splitting mode of failure. 28 days of acid conditioning increased the bond strength of BFRP specimens by 5.45–53.9% and for steel specimens by 1.93–28.73% of their initial strength. 56 days of acid conditioning decreased the bond strength of BFRP specimens by 1.33–24.86% and for steel specimens by 8.78–18.44% of their initial strength.

The number of civil infrastructures which have deteriorated and no longer fulfill the requirements of safety standards is continuously increasing day by day. Over the past few decades, there has been increasing interest in applying adhesively bonded composites to repair existing and/or strengthen new civil engineering structures. Extensive research has been conducted on Fiber Reinforced Polymer (FRP) strengthening of concrete structures, whereas relatively less work has been done on FRP strengthening of steel structures. Among the FRP materials available, Carbon Fiber Reinforced Polymers (CFRP) were found to be the most suitable for strengthening steel structures because of their well known high mechanical properties and high strength to weight ratio. This paper presents an experimental investigation on the effect of CFRP strengthening in the load carrying capacity, stiffness and deformation characteristics of undamaged and damaged steel beams. The effect of end anchorage on flexural strengthening of steel beam is also investigated.

Many technologies had origin through the continuous and careful observation of unnoticed features of the species present in our nature. The self cleaning property of lotus leaves is a remarkable one among them, known in the name “lotus effect”. It has found a huge place in the civil industry. The exterior house paints are always subjected to wide fluctuation in atmospheric temperature conditions such as exposure to winters, hot summers, raining, etc. which reduces its durability and causes algal growth. Thus by effective incorporation of nanotechnology with this lotus effect, it has become able to provide self-cleaning ability along with air purification and antibacterial performance to construction materials like paint, tiles, etc. Nanomaterials like silicon, Titanium Dioxide etc. help to improve functionalities like water or stain resistance, UV protection, scratch resistance etc. When nano TiO2 was added to paint it degraded the polluting compounds at material surface by photocatalysis. Addition of it with cementitious materials displayed multiple photocatalytic functions and self cleaning properties. This review paper throws light into the repellent property of nano TiO2 when used in paint thereby enhancing aesthetic appearance of surfaces and effectively reducing the cost of routine maintenance. Rhodamine B removal ability of nano TiO2 is reviewed.

Reinforced concrete structures often have to face modifications in performance during their service life mainly because of ageing and exposure to aggressive environment. Near Surface Mounting (NSM) and Embedded Through-Section (ETS) are two effective techniques for the shear strengthening of reinforced concrete (RC) beams. NSM technique involves cutting of a series of shallow grooves in the concrete cover of the structures and inserting steel/FRP bars into them and ETS technique consists of drilling holes across the full depth of the beam cross-section and inserting steel/FRP bars into them, thereby bonding the bars with the surrounding concrete using appropriate bonding material. This paper presents the results of experimental investigations on RC beams strengthened in shear using CFRP bars in Embedded through section (ETS) and Near Surface Mounting (NSM) methods. Three point bending tests are conducted to find the effect of ETS/NSM bar spacing and ETS/NSM bar orientation on the load carrying capacity of RC beams. The experimental results confirms the effectiveness of ETS and NSM methods and a comparison is made in terms of shear strengthening ratio, load carrying capacity of RC beams.

Concrete is one of the most widely used construction material in industry. It has high compressive strength but low tensile strength. The low tensile strength may result in crack formation which seriously affects the life of concrete. A solution to this is the introduction of self-healing properties in concrete. Also the properties of hardened concrete will mainly depend on its extent of hydration. Proper curing methods can be used to achieve proper hydration. Bacterially induced self-healing by calcium carbonate precipitation has been proposed as an eco-friendly method in recent years. The bacterium selected for the study is Bacillus Subtilis JC3. The present study concentrates on the effect of bacteria as self -healing agent in self-curing concrete and its optimum percentage in strength aspects of hardened concrete.

The RGHLS is a type of diagrid structure that has been developed in recent years. It consist of two columns. The major columns are designed as inclined members in major direction from bottom to top of RGHLS. They sustain the major percentage of vertical loads. The secondary columns have to be segmented in a helical direction in order to form the hyperboloid latticed shells. Secondary columns sustain much less vertical load than major columns. They are more commonly used in purpose-driven structures, such as water towers (to support a large mass), cooling towers, and aesthetic features. The objective of this study is to compare the result of the Model analysis by changing the shape of major and secondary column and also the performance of the structure when the position of the central axis of the structure is varied with respect to its height. The software used for this study is ANSYS. Height on the either side of the horizontal axis is varied and optimum height that exhibit best result is determined.