Proceedings of SECON 2020

Self-compacting concrete (SCC) is concrete which is proportioned in such a way that it is compacted by its weight assuring complete filling of formwork even when access is hindered by narrow gaps between reinforcing bars. The rheology properties were determined by the test as filling ability, passing ability, and segregation resistance. Strength properties were determined by compressive, split tensile, flexural strength. The successful utilization of fly ash and metakaolin in SCC mixes not only lower the cost of SCC but also provide a solution to the disposal and environmental problems connected with these materials.

The concrete is a composite material made by proper proportions of fine aggregates, course aggregates along with proper water to cement ratio. This composite in hard state very strong in compression and having ability to take more gravity loads. Concrete members are weak in tension hence commonly steel is adopted as reinforcement in all over the world. Several researchers tried to enhance the tensile reinforcement by various alternative materials and also successfully showed the importance of various fibres and alloy materials in concrete. The materials used for enhancing tensile strength must possess good bond strength, thermal resistance, corrosion resistance and recyclable. In this present paper, an experimental work has been conducted to know the behaviour of polypropylene (PP) Geo-fabric as partial replacement for reinforcement in concrete for non-importance small scale structural members. Different tests like compression, split tensile, flexure tests have been conducted with the presence of PP Geo-fabric and results shown better performance compared with normal conventional test specimens.

Dual-Pipe Damper (DPD) is a metallic yielding device for the passive earthquake energy dissipation. It consists of two welded pipes, which is positioned to take shear. DPD works in flexural form, on the basis of plastic-deformation of steel materials. According to previous researchers, multistory frames equipped with DPD exhibit a stable hysteresis loop with excellent energy absorption capacity under dynamic non-linear time—history analysis. Present study investigates the lateral resisting capacity of DPD by pushover analysis and to find out the best dimensions of DPD for buildings conforming to IS 800:2007. From this study, the optimum frame equipped with DPD is identified which can be utilized for a better seismic retrofitting.

The behaviors of masonry infill under the action of sudden disasters are highly unpredictable. Infill is very strong and behaves better under the action of gravity loads because of its strong nature under compression but it shows versatile behavior under shear. In any kinds of high rise buildings infill actions are ignored in design but contribution of infill under lateral loads are highly significant. The infill contributes to strength and stiffness of frames under lateral forces and also the interfaces between frame and infill are fails because of its weak bond. Several researchers studied the significance of strengthening of masonry infill and stated that significance of strengthening under flexure and shear. In this present paper an experimental work has been presented on two different types of Geo-synthetics strengthened to brick masonry infill and results are compared with unreinforced conventional masonry infill elements. The results shown the better performance in load carrying capacity and also in flexure and shear compared with conventional specimens.

Landslides are hazards which frequently occur and affect the life of human, animals and damage properties. Kattippara Panchayath is a highly landslide prone area in which landslides had occurred in different locations and public have been asked to stay away from this area. Currently there are no effective strategies to reduce the risks of landslides. A Geographic Information System has proved to be a useful tool for analysing and managing landslide related data. Landslide susceptibility map of the study area is prepared using Arc GIS software by combining some of the critical factors like land use pattern, geology, geomorphology etc. It can be used for assessing the risks of landslides, for developing early warning systems and mitigation plans. This paper seeks to identify the existing governance gaps in the study area, to ascertain the status of existing risk reduction measures available, the constraints associated with such measures, and thereby to suggest suitable measures to fill the identified gaps. This paper concludes with a synthesis of governance gaps and opportunities to reduce the risk of such disasters.

Structural safety has always been an important factor for the design of civil engineering projects. One of the mechanisms of structural failure that has gathered increased attention over the past few decades is referred to as progressive collapse. Progressive collapse is the spread of an initial local damage from element to element, resulting eventually in the collapse of an entire structure. The potential cause that can trigger progressive collapse are categorized as: aircraft impact, design/construction error, fire, gas explosions, accidental overload, hazardous materials, vehicular collision, bomb explosions, etc. The aim of this study is to investigate the performance of 15 storeyed geometrically regular and irregular buildings with steel frame system to progressive collapse. Alternate path method based on dynamic analysis is performed based on Indian standard codes. According to alternate path method, the structure is designed such that if one component fails, alternate paths are available for the load and a general collapse does not occur. The response of the building to progressive collapse was studied in detail using structural software for building analysis and design, ETABS.

This paper presents the numerical investigations carried out on pultruded prototype glass fibre reinforced polymer (GFRP) composite bridge deck panels under static loading. To carry out the analysis decks with four different core shapes having almost same cross sectional area and weight were taken. The loading was applied with a patch of size 580 mm × 230 mm by displacement controlled method until failure. To understand the behavior of the deck, loading was applied at the center of the deck. Based on these observations trapezoidal section is to be found more beneficial in terms of load carrying capacity and secant stiffness. Strengthening of the GFRP deck with trapezoidal core shape were done by filling alternate cores with light weight ultra-high strength concrete with steel reinforcement on the top portion at a spacing of 100 mm and 150 mm respectively. Based on the load carrying capacity and the deflection limit the optimum configuration is taken and their load carrying capacity is compared with the same model without strengthening.

Self-compacting concrete abbreviated as SCC is a recently developed concept in which the ingredients of the concrete mix are proportioned in such a way that the concrete is compacted by its own weight without or little vibration, assuring complete filling of formwork even when access is hindered by narrow gaps between reinforcing bars. Cement is the most important constituent material, since it binds the aggregates and resists the atmospheric action. Manufacturing of cement emits about 0.8 ton of CO2 in atmosphere for every ton of cement manufacture. The utilization of supplementary cementing materials as natural pozzolans like dolomite powder, fly ash, GGBS etc. in concrete production is one of the solutions to reduce the cement content. This paper deals with the fresh and hardened properties of self compacting concretes made with combination of GGBS and dolomite, GGBS and fly ash as cement replacement in different amounts. The trial mixes are formed based on IS 10262: 2019. The workability properties of the mixes are evaluated by workability testes such as slump flow test, V-funnel test, L-box test. The hardened properties of the concrete are evaluated by compressive strength, flexural strength and tensile strength. The successful utilisation of fly ash, GGBS and dolomite powder in SCC mixes would not only lower the cost of SCC, but could also provide a solution to the disposal and environmental problems connected with these materials.

The disposal of Construction and Demolition (C&D) waste generated in the cities has become a serious environmental problem nowadays. The use of Recycled Concrete Aggregates (RCA) obtained from this C&D waste can reduce the amount of virgin aggregates for pavement construction. In this study, the recycled concrete aggregates are used in the manufacture of Stone Matrix Asphalt (SMA) mix. The fine and coarse aggregates in SMA mixes are partially replaced by RCA. The Marshall and volumetric properties of the SMA mixes containing RCA are evaluated and compared with the conventional SMA mix. The use of these SMA mixes prepared with RCA reduces the volume of natural resources consumed and solves the disposal problem of the C&D waste. This study thus actually paves a sustainable way for the asphalt pavement industry.

Self-compacting concrete is a fresh concrete that flows under its own weight and does not require external vibration to undergo compaction. It is used in the construction where, it is hard to use vibrators for consolidation of concrete. The acute shortage and high price of river sand led to the enormous usage of M sand in construction. Use of quarry dust as a fine aggregate is a good alternative to M sand and a better remedy to the disposal of quarry dust. Quarry dust is a by-product from the crushing process during quarrying activities. Large scale of cement production causes the discharge of high amount of carbon dioxide resulting in global warming. This can be reduced by the use of metakaolin, as a partial replacement for cement contributing to higher workability, long term strength and to make concrete more economically available. In this study an attempt is made to study on the M40 equivalent fly ash based self-compacting concrete is partially replacing cement with metakaolin by 10, 15 and 20% of weight of cement and the fine aggregate is partially replacing with quarry dust by 20, 25, 30 and 35% of weight of fine aggregate and in order to evaluate the strength parameters, they are compared with M40 equivalent fly ash based self-compacting concrete.

Self-compacting concrete (SCC) is a fluidic concrete 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. High amount of cement and chemical admixtures used in SCC reduces its wide scale usage. Alccofine can be used as a better substitute to cement due to its cementitious properties. The work aims at the possibility of recycling waste plastic granules (polyethylene terephthalate (PET) used in the plastic bag production) as a fine aggregate instead of sand in the manufacturing of the self-compacting concrete. Cement is partially replaced with alccofine at 8, 10 and 12% by weight of cement and the optimum percentage of alccofine was obtained. To the mix with optimum percentage of alccofine, the fine aggregate is substituted with the plastic granules at dosages 5, 10, 15 and 20% proportions by the volume of the fine aggregate. The fresh and hardened properties of M40 equivalent fly ash based self-compacting concrete were compared and evaluated.

Sustainability is a wide accepted concept in modern construction scenario. Even though the construction industry is revolutionizing in a significant manner in terms of both equipment and materials used, the cost of construction has skyrocketed along with the deteriorative impact on environment. This resulted in the adoption of a more balanced approach with the environment which lead to the adoption of natural coconut fibre for the strength enhancement in concrete. Coconut fibre is available in abundance, which makes it quite viable as a reinforcement material in concrete. Significant changes in constituents and properties of concrete were initiated and Engineers started using coconut fibre as supplementary materials in concrete, often with adequate considerations. Through research and tests the change in properties of concrete when normal water is replaced by magnetic water is observed. The magnetized water helps in increasing the compressive strength in concrete and the problem of shrinkage crack formation due to the higher heat of hydration is eliminated by the addition of coconut fibre [1]. Addition of Coconut fibre helps in increasing the flexural strength of concrete. The magnetized water contributes to higher strength characteristics of the concrete and fibre being natural in origin is ecologically sustainable and can bring down the global carbon footprint quite effectively.

Nowadays various construction techniques are adopted in order to increase the seismic performance of the building. The latest technology of “weak beam and strong column” is given more importance and hence the columns in a seismic resistant structure play a vital role in assessing the overall strength of the building against the effect of seismic forces. Oblique Column is the column, which neither parallel nor at right angles to a specified line, means they are slanted or rotated at an angle. In this paper, seismic performance of Y shaped oblique column in symmetrical and asymmetrical high rise building was studied using Etabs 2016 software and was compared with conventional column building. Space utilisation achieved by adopting Y shaped column was also studied. Optimum angle of inclination of Y was investigated. Parameters like maximum displacement, storey drift, time period of high rise building with Y shaped were studied by performing time history analysis and compared with conventional column building.

Copper manufacturing industry produces bulk quantity of copper slag as an industrial by-product. Its management and disposal is a major challenge for the environment, thus an urgent need for its potential alternative is recommended. The intent of the current work was to design self-compacting concrete mixes incorporating copper slag as fine aggregate replacement. Self-compacting concrete is a highly flowable type of concrete that spreads into the form and compact without the need for external vibration. Self-compacting concrete was developed as per IS 10262:2019 using copper slag as fine aggregates with partial and full replacement of sand. Five different SCC mixes with 0% as control mix, 10%, 20%, 30%, 40% and 50% of copper slag substituting sand were cast and tested for both fresh and mechanical properties. The results obtained indicates that the flowability and passing ability of SCC mixes enhanced as the content of copper slag increased. Compressive strength and split tensile strength were also increased as the content of copper slag enhanced. A substitution of up to 40% copper slag as a sand replacement yielded compressive strength of about 41.23 MPa.

Concrete is the one of the most widely used construction material. Portland cement is the main ingredient for making concrete. The cement industry is responsible for about 5% of total CO2 emission worldwide, which is the main cause of global warming. In order to reduce CO2 emission, an ecofriendly construction material called geopolymer concrete was developed as a substitute for cement. Geopolymer concrete is a type of concrete which is produced by the chemical reaction of inorganic molecules. The aim of the study is to develop a geopolymer concrete using metakaolin and fly ash as binder material. Different proportion of metakaolin and fly ash were prepared by varying the proportion of activator to binder ratio from 0.6 to 1.0. The performance of different mixes were compared using mechanical properties like compressive strength, flexural strength and split tensile strength. Sodium hydroxide solution with 12 M concentration and sodium silicate solution were used as activator in a proportion of 2:5. The coarse aggregate consisted of graded gravel with a maximum size of 12.5 mm and fine aggregates was M sand. From the present study geopolymer concrete of compressive strength 32.21 N/mm2 was developed. The optimized mix was obtained with the activator to binder ratio 0.9 as well as 60:40 proportion of metakaolin and fly ash.

The developments in construction techniques, materials, structural systems and analytical methods for analysis opened the door for the growth of high rise buildings. The lateral resistance of such a structure is offered by interior structural systems or exterior structural systems. Recently, grid systems are adopted in tall buildings due to its structural efficiency, superiority in aesthetic appeal and flexibility in architectural planning. Diagrids and hexagrids contain diamond shaped modules and hexagons respectively, throughout exterior of structure and they don’t have any external vertical columns. The behaviour of high rise buildings using combination of grid systems has not been explored. This study focuses on the structural performance of high rise steel buildings for various combinations of grid systems. In this study ETABS V16 software was used for modelling and analysis of a 36 storey building with regular floor plan. Models were created using combinations of diagrid and hexagrid systems with optimum diagonal angle and module density. Time history analysis of these models were carried out to examine their seismic performance. The combinations with better performance were determined Combined grid system is a viable option when governed by overall weight and cost.

Cement concrete blocks are one of the popular masonry units used in construction. The conventional binder, cement cause heavy impact on environment due to its high utilization of natural resources and emission of CO2 during production. To overcome this issue an attempt has been made to develop geopolymer binder from terracotta tile waste as alternative to cement and its application in concrete blocks. In this paper sustainability evaluation of terracotta tile waste based geopolymer concrete block (GCB) over cement concrete block (CCB) has been evaluated through a modified frame work by considering four aspects of sustainability. Socio-cultural factor with three sub criteria (acceptance, awareness and decentralized production), economic factor with four sub criteria (infrastructure, unskilled labour, accessibility to material and material efficiency), technological factor with two sub criteria (strength and durability), environmental factor with three sub criteria (energy efficiency, waste management, and feasibility for reuse or renewability) of GCB and CCB were evaluated. Quantitative evaluation of four sub criteria under technological and environmental sustainability were discussed in detail using results of experimental research conducted as per the standards and calculated amount of embodied energy and CO2 emission of both the blocks, which reveals that GCB is more sustainable than CCB. However GCB being in the infancy stage, remaining eight sub criteria under socio-cultural, economic and environmental factors were qualitatively analyzed using available information. The overall result indicates that GCB is more sustainable than CCB.

There are some impediments to the effective use of conventional flat web steel girders such as poor web stability and low buckling strength. To overcome these kinds of problems, the idea of using steel corrugated webs to bridge girders has been introduced to get enhanced web stability and buckling strength. The existing studies on bridge girders with steel corrugated webs are focused on single corrugated web girders. According to previous researches, large forces generated on the girders result in buckling of single corrugated web. This paper focuses on Double corrugated web girders. The Double corrugated web girders can be strengthen either by providing stiffeners along with the corrugated web or by making the web as a composite one. This paper consists of buckling investigations on Double Corrugated Stiffened Steel Web Non-prismatic girders (DCSSWG) consist of two stiffened corrugated steel webs with steel flat flanges and also on Double Corrugated Composite Web Non-prismatic girders (DCCWG) having Ultra-Lightweight Cement Composite fill (ULCC) in the space between two corrugated steel webs. Buckling performance of Non-prismatic girders with Double Corrugated Stiffened Steel Webs and Double Corrugated Composite Webs having different tapered ratios are investigated using ANSYS 16.1 software. The results obtained from the study have shown that Non prismatic girders with Double Corrugated Composite Webs show more buckling strength as compared to Double Corrugated Stiffened Steel Webs for the same tapered ratio.

Single concrete filled steel tube (CFST) members are widely used in building structures and bridges due to their high strength, ductility, toughness, fire resistance[1], energy absorption capacity, fast track construction and low cost, which is due to the composite action between steel tube and core concrete. This study examines structural performance of composite columns comprising of concrete filled steel tubes connected with double corrugated plate. T-shape, C-shape and Z-shaped sections are selected for this study. Non-linear finite element (FE) model was developed using ANSYS 16.1 to study structural performance of these special shaped CFST columns (SCFST). SCFST columns were analysed under axial compression, eccentric and lateral loads. Failure pattern, buckling capacity, strength and stiffness of specimens were investigated.

Particle damper (PD), an innovative type of passive vibration control system, is a developing concept in the current period. This type of damper consists of small particles that are placed in the cavity of the primary structure which is likely subjected to vibration. The energy dissipation mechanism occurs due to the inelastic collision of particles present in the damping cavity and friction between particles. Compared to other passive vibration control methods, particle damper can be effectively introduced into structure without significant modification of primary structure. This study is mainly intended to the experimental investigations on the behaviour of particle damper under varying parameters. Parametric study investigates the efficiency of particle dampers in mitigating dynamic responses of MDOF structures. This study focuses on the performance of particle damper by using different types of particles and their combinations. Types of particles used in this study are metallic (steel balls) and viscoelastic polymer (silicone rubber balls).

Modern aircraft structures uses more lightweight materials such as composites for their design. This makes the aeroelastic study an extremely important aspect of aircraft design. By having more light weight control surfaces, the control effectiveness study becomes vital in today’s scenario. Control effectiveness is the ability of a control surface such as an aileron or a rudder to produce aerodynamic forces and moments to change the airplane orientation and manoeuvre it along the intended flight path. This paper presents the static aeroelastic analysis of a typical reusable launch vehicle focusing on control effectiveness of elevon. A Reusable Launch Vehicle (RLV) is the space analogy of an aircraft. Ideally it takes off vertically on the back of a dispensable rocket and then glides back down like an aircraft. MSC PATRAN and MSC NASTRAN were the software’s used for Finite Element Modeling and Analysis. The main aim of the analysis is to compute the control effectiveness of launch vehicle along its trajectory to determine whether it is efficient to control the vehicle. The objectives of this work are, to study the control surface effectiveness of elevon by carrying out static aeroelastic analysis using NASTRAN inbuilt aerodynamics, for a typical Reusable Launch Vehicle (RLV).

Recent earthquakes highlighted that, conventional steel moment frame (SMF) shows brittle failure due to the seismic actions. Greater damages are due to the stress concentration at the interface of beam and column. A number of improved beam to column connection design strategies have been proposed. Reduced beam section (RBS) connection was introduced as a safety approach to reduce stress concentration at the panel zone. RBS promote the formation of plastic hinges within the reduced beam section of the beam at a specific distance from column face. The finite element analysis of steel beam-column connection arrangement was carried out for studying the strength behavior of beam column joint. In this paper cyclic analysis of bolted steel beam-column connections with RBS were using finite element analysis software ANSYS 16.1. The cyclic behavior of bolted beam column joints with and without RBS techniques are investigated. Cyclic behavior of variable configuration of reduced beam sections was also examined. From the analysis, it is observed that the specimen with RBS dissipates more energy than the conventional moment connection. Connection region remained in the elastic area due to plastic hinge formation in the RBS zone. The applied RBS geometry protects the connection and its components (endplate, column flange, bolts, welds) from failure. To investigate the effectiveness of RBS in inclined beams, 3D finite analysis is performed on the frame with a slope of 10°, 20°, 30° from the orthogonal.

A construction material that removes pollutants from the air as it keeps its surface clean. This new astonishing concrete that not only keeps itself clean but also removes pollutants from the air is called Self-Cleaning Concrete. Self-cleaning concrete is a technique to reduce the air contaminants such as NOx, SO2, CO2 and VOC’S from vehicular traffic on streets, any industrial activity and the urban environment. In this paper a study has been carried out on the compressive strength of self-cleaning concrete by introducing the photocatalytic materials such as titania (TiO2), zinc oxide (ZnO), aluminium oxide (Al2O3). Self-cleaning property of the photocatalytic concrete is studied by using RhB (Rhodamine dye) discolouration under UV light, a standard test for self-cleaning cementitious materials. The properties of self-cleaning concrete is then compared with the that of M25 grade normal concrete and the results are studied.

Slim-floor beams are a novel typology of steel beams where the steel profile is fully embedded within the concrete floor depth. Slim-floor beams are a well-known and cost-effective solution that permits a significant reduction of floor thickness, and are increasingly used in industrial and commercial buildings. While the use of this system is increasing in the construction practice, the available investigations on its thermal performance are still scarce. Therefore, this paper focuses on analyzing the fire behaviour of slim-floor beams with hollow-core slabs as a flooring system and improving its fire-resistance. A finite element model was developed through ANSYS 16.1 and the thermal performance of different type of composite beam configuration and steel plate thickness was studied by conducting transient thermal analysis. Also, structural analysis of the following models using these material sections for SFB were conducted and its structural behaviour was studied. The conclusions suggest that the thermal performance of SFB configuration can be improved by using innovative solutions, advanced materials or external protection.

Current cement production across the globe is 4.0 billion tonnes per annum and growing at 4% annually and it have a huge effect on the global warming. This calls for the development and use of alternative binder materials which will have less carbon footprint on environment. The sustainable alternatives to conventional cement can be developed by utilizing the cementitious properties of industrial byproducts like flyash, bottomash and GGBS. Flyash and GGBS are used as binder material 50% each. Bottomash is used for the replacement of fine aggregate. NaOH, Na2SiO3 were used as alkaline activators. Casting and curing of geopolymer concrete (GPC) is done under ambient temperature. This paper was aimed at examining the fly ash-ggbs based GPC along with replacing the fine aggregate using bottomash. Study deals with investigating the influence of varying molarity of NaOH viz., (8 M, 10 M, 12 M, 14 M, 16 M) and to examine the influence of varying bottom ash content (25–100%) on the mechanical properties of geopolymer concrete. Also to establish relative performance of GPCs with respect to OPCs.

Self-compacting concrete (SCC) is a flowing concrete that does not require vibration and should not be vibrated. Palm oil fuel ash (POFA) is a by-product obtained during the burning of waste materials such as palm kernel shell, palm oil fiber, and palm oil husk. It can be utilized to partially replace cement in a concrete mix considering its good pozzolanic properties and high performance in the development of strength of concrete. This work highlights the scope of finding the properties of M40 equivalent (considering structural applications) fly ash based self compacting fiber reinforced concrete in cooperating waste carpet polypropylene fibers and palm oil fuel ash. Cement is replaced with palm oil Fuel Ash at 10, 20, and 30% by weight of cement and optimum percentage of palm oil fuel Ash is found. In the self compacting Concrete mix having optimum percentage of palm oil fuel Ash, Polypropylene carpet fiber fractions at 0.25, 0.5, 0.75, 1% by volume of concrete are incorporated and the optimum percentage of addition of waste carpet fibers is found by testing the mechanical properties. The fresh and hardened properties of the M40 equivalent fly ash based self compacting fiber reinforced mix with optimum palm oil fuel ash and optimum waste carpet fibers were compared and evaluated.

Pull planning is an approach where the schedule is worked in reverse order. In pull planning, the final decisions are taken by the Project Manager. This decision making involves a chain of correspondence from Construction Manager to Project Engineer to Site Engineer and finally to the Foreman. Transfer of workers from one site to another is also one among the decisions that are taken by a Project Manager. To select a worker, a manager shall desire certain attributes depending on the requirement for the transfer. However, the cascading chain of correspondence results in a biased decision. Thus, selection of a suitable worker to transfer is an issue. In this paper, a set of construction labour selection attributes are identified based on expert interviews. The attributes identified are Skill, Regular attendance, Responsibility, Health, Safety at work, Discipline, Technical Soundness, Daily wage rate, Language and Previous accident history. These identified attributes are then quantitatively analysed using questionnaire survey and literature reviews. They are then given weightage based on the study. Selection attributes can be collectively called a Worker Profile. This worker profile can be introduced to reduce the gap between the Manager and a foreman. However, the benefits of this worker profile in the pull planning process need to be evaluated in real-life cases.

Brick is a widely accepted building material used from ancient civilization to this era. The fields of brick manufacture have been undergone tremendous changes through several decades. Use of cement and lime in the soil for production of brick may stabilize the soil and thereby improve the strength and durability properties of bricks. On the other hand the use of such materials results in high energy consumption and production of CO2. Therefore making the brick environmental friendly and cost effective, the addition of metakaolin and clam shell powder, instead of cement can be done. This research shows the development of an optimum mix for laterite soil brick by adding metakaolin-clamshell powder (MK-CSP), an artificial pozzolana and waste material respectively. The hydration process of metakaolin, which containing high silica and alumina content react with the calcite present in clam shell powder that containing calcium carbonate result in the formation of calcium aluminate and calcium silicate hydrate at the time of hydration [1]. These cementicious compounds densify the loose clam shell powder paste. The effect of addition of various quanties (2.5% and 2.5%, 5% and 5%, 5% and 10%, 10% and 5%, 5% and 15%.10% and 10%, 15% and 5%) of metakaolin and clam shell powder respectively by weight of laterite soil on mechanical, physical and durability properties of brick were established.

Shell foundations have been used as an economic alternative to the conventional flat shallow foundations, in situations where heavy loads are to be transferred to weaker soil. Among the shells which have come into wider use in foundation, is the conical shell. The frustum of cone is probably the simplest form in which a shell can be used as foundations. This paper aims to study about a different foundation shape that reduces the foundation cost by reducing the required amount of concrete and reinforcing steel bars. Also, to achieve lower soil stresses by changing the foundation shape which will result in reduced settlements and foundation stresses. Analytical studies are performed on circular flat foundation and conical shell foundation using finite element software ANSYS 19.0 and their performances such as ultimate load carrying capacity and soil settlement characteristics have been compared.

Packing of the particles has great impact on the performance of concrete. When only the ordinary Portland cement was used in concrete, the voids content tends to be large. To overcome this problem, supplementary cementitious materials finer than OPC is added to fill into the voids so as to improve the packing density. In this study wet packing method is used to evaluate the packing density of concrete containing supplementary cementitious material as Metakaolin. This paper deals with the packing density and the strength characteristics of concrete developed by varying the metakaolin content from 0 to 20% by volume. There is an optimum percentage for the replacement of cement with Metakaolin. The results show better positive results while comparing with the normal concrete.

Plastic shrinkage cracking has become one of the serious problems in concrete elements especially in structures with large surface area/volume ratios and affect the durability of the structure. This paper quantifies the effectiveness of fly ash and alkali resistant (AR) glass fibre on cracking of plastic self compacting concrete. The aim of this experimental work was to study the plastic shrinkage evolution in fly ash based self compacting concrete (SCC) and to examine the effectiveness of alkali glass fibre in SCC to reduce shrinkage cracks. The test was carried out in the mould based on ASTM C1579. At early ages compressive strength of the SCC mixes was similar to that of the reference mix and the maximum strength was observed for 25% replacement by fly ash and is considered as the reference mix. Alkali resistant glass fibres of 12 mm length were added to reference mix of SCC at different dosages of volume fractions of 0.1, 0.2 and 0.3% and the shrinkage test were conducted. The plastic shrinkage test results of Ordinary concrete, reference SCC and SCC mix with various dosages of glass fibre were compared. The SCC mix with AR glass fibre of Volume fraction of 0.2% was found out to be most effective.

Modern world is facing a serious situation of waste management, especially plastic waste. There has been a considerable imbalance between the availability of conventional building materials and their demand in the recent past. On the other hand various type of sands such as foundry sand are abundantly available and the disposal of waste plastics (Poly Ethylene Terephthalate, Poly Propylene etc.) is a biggest challenge, as repeated recycling of PET bottles pose a potential danger of being transformed to a carcinogenic material and only a small proportion of PET bottles are being recycled. In the present study, the effectiveness of PET bottles on manufacturing of bricks is analyzed and properties of plastic-soil bricks are assessed. PET bottles are melted and into this molten plastic mix, sand is added in various proportions. Plastic-soil bricks using M sand and as well as foundry sand are manufactured. Various standard tests on bricks are conducted as per IS 3495 (Parts 1–4) such as compressive strength test, water absorption test, efflorescence test, hardness test, soundness test, impact test, thermal resistance test, prism Test. Through the results obtained from the standard tests, the optimum percentage of plastic is estimated. It is studied that plastic-soil bricks show excellent behavior when compared to conventional burnt clay bricks.

Numerous ground improvement techniques have been used to stabilize marginal soils to make it more feasible for construction purposes. Soil reinforcement using natural fibres is increasingly preferred as they are sustainable, readily available and inexpensive. This study aims at improving the engineering properties of lateritic soil using the natural coir fibres as reinforcement material. Laboratory tests such as UCS test and direct shear test have been carried out to evaluate the effect of various fibre parameters such as fibre content and fibre length on the engineering properties of soil. Results showed significant improvement in the strength characteristics of lateritic soil after the addition of coir fibres. Optimum fibre parameters that contributed to the enhanced performance of soil were also identified.

In recent years, Pervious Concrete (PC) has been increasingly promoted as an effective sustainable drainage system to mitigate surface flooding in urban areas. However, the pore structure of PC can become clogged by sediment particles and its ability to drain storm-water runoff gradually decreases. Therefore an alternative to PC, which is resistant to clogging, should be developed. This Clogging Resistant Pervious pavement block (CRP) was prepared by introducing straight pore channels of varying numbers into mortar for obtaining different porosity. Flexible pipes were introduced to 1:2 mortar mixes for developing straight pore channels in the mortar cubes. Mortar cubes of porosity starting from 1 to 6% were casted. Optimum porosity was determined by permeability test using falling head permeability apparatus and compression test. Optimum porosity was obtained at 4% porosity for CRP. This innovative system will help alleviate urban flooding and contribute towards a more sustainable urbanization.

Timber Concrete Composite (TCC) beam is a structural technique widely used for strength and stiffness upgrading of new and existing timber floors, bridges, buildings etc. The main reason for this development is the advantages it offers in terms of higher stiffness, lighter weight, and cost effective compared to RC beams. A TCC beam comprises a concrete slab connected to a timber beam by means of shear connectors. The shear connectors resist the shear and plays a critical role in TCC beam by connecting and introducing a composite action between the upper concrete slab and lower timber beam. Hence to ensure and improve this composite action, a better connection of timber and concrete along with shear connectors is necessary. In this study, a new connection system is introduced in the form of interlockings between timber and concrete. The behavior of TCC beam with interlockings of types rectangular and dovetail joints is analysed using ANSYS 16.1 and the best connection system is selected based upon the load deflection behavior, the relative slip between concrete and timber as well as direct stress on shear connectors of TCC beam. Further TCC beam under longitudinal non-prismatic condition is also studied with the best connection system. From the results obtained it was concluded that TCC beam with dovetail joint of tenon angle 60° is the best joint. Also TCC beam under non prismatic condition with central rise 50 mm showed better performance in terms of load carrying capacity and deflection.

An alternative structure for RC beam is a challenging factor in the field of structural engineering. Various studies had been conducted to introduce a cost-effective light weight structure which can replace RC structure. Studies on Glass Fiber Reinforced Gypsum (GFRG) panel sandwitched with Cold Formed Steel (CFS) is one such recent alternative technique to RC structure. In this paper, a GFRG laminated beam developed and strengthened by encasing Cold Formed Steel (CFS) internally and externally is analyzing using ANSYS 16.1 Software for evaluating flexural behaviour of developed beam. It is expected that this combined arrangement of GFRG panel and CFS will provide a cost-effective, light weight and load bearing structure with substantial strength to replace RC.

Unreinforced masonry wall (URM) is a traditional method and are widely used all around India. URM can be commonly found in reinforced concrete structures in many earthquake prone countries. Masonry walls are more vulnerable during earthquakes. URM structures are not naturally stable and can generally increase the lateral strength and stiffness of the structural system and thus improve the structural performance up to a certain range of seismic load. Hence, it is essential to find solutions to strengthen URM walls. The present study aims at investigating the in-plane shear behavior of solid concrete block masonry wall and masonry strengthened with GFRP mesh and polypropylene fiber (PP) externally bounded as a reinforcing material. The tests are conducted to determine the optimum percentage of polypropylene fiber. An experimental study is carried out involving a series of masonry walls made of concrete blocks are prepared and are reinforced with GFRP and PP fiber. The wallettes are subjected to diagonal axial compression test according to ASTM E 519-02. The main focus of the study is to investigate the strength characteristics of masonry wall and to know the practical applications of this technique. The strengthening effect caused by the concrete block masonry on in-plane shear behavior including failure modes, shear strength, modulus of rigidity and ductility are investigated. The walls are subjected to in-plane diagonal tensile (shear) test. The shear strength parameters are studied and the application of fibers for strengthening of masonry walls is observed.

The extensive use of thin-walled steel structural systems in the building and construction industry is mostly indebted for their high strength to weight ratio attributes and remarkable fabrication versatility. Corrugated plates which falls in this category, also have a wide range of application in various engineering fields. They are lightweight, economical, and have much higher load carrying capacities than flat plates. The corrugation shape provides continuous stiffening which permits the use of thinner plates. Fabrication costs for elements with corrugated panels are normally lower. A corrugated column is a hollow column constructed by welding together four corrugated panels. Multi Cellular Corrugated Steel Column (MCCSC) is a kind of hollow column where Multi Cellular stiffeners are provided inside hollow column. Three different types of Single Skin Corrugated (SSC) columns with different stiffener configurations (diamond, plus and cross shapes) were chosen. Stiffeners increases the load carrying capacity as well as the buckling capacity of the column. Double Skin Corrugated (DSC) columns with square and circular core at the center to which stiffeners are welded is also developed. In this paper the behavior of MCCSC subjected to axial and eccentric loading is studied using ANSYS Workbench 16.1 software and it was found that column with diamond shaped stiffener showed best performance in both SSC and DSC columns.

In concrete industry there has been increasing trend towards use of recycled aggregate to save lot of natural resources and to provide lightweight concrete (LWC). Compared with conventional concrete, LWC can considerably cut back the dead load of structural elements. The low biodegradability of plastic and the presence in massive quantities of waste plastic negatively impact the environment. This study focuses on the development of light weight concrete using waste materials as a part of waste management. This study presents the mechanical properties of concrete by using waste plastic as a partial replacement of coarse aggregate in various proportions of 5, 10, 15, 20% and by replacing cement with 10, 20, 30% of fly ash. The low densified composite material was much lighter than that of the conventional light weight concrete. To offset the reduction of strength due to the less densified structure, the addition of mineral admixture was proposed. The investigation using fly ash has showed an improvement in the compressive strength.

It is expected that in the near future, the civil engineering community will have to produce structures in harmony with the concept of sustainable development through the use of high-performance materials with low environmental impact that are produced at a reasonable cost. Magnetic water concrete provides one route towards this objective. When water passes through a magnetic flux it is known as magnetized water. The magnetic effects changes the physical & chemical parameters of natural water, resulting in improvement of filtration properties and increase dissolving properties of water Su et al.(Cem Concr Res 30, 2000 [1]). One of the basic characteristics of magnetically treated water, which has major importance in concrete making, is its pertaining to colloidal particles allowing a more complete hydration process to occur and enhancing the mechanical strength of concrete. The magnet used to make the water magnetic is permag-N406 Bharath et al. (JCPS 9(4) 2016, [2]). The changes in properties of magnetized water such as pH value, hardness and evaporation rate were studied. The optimal value of magnetization is also carried to find out the maximum exposure time of water with the magnetic field. Study on compressive strength, split tensile strength, workability and plastic shrinkage of concrete were carried. Cement is also partial replaced with Nano silica by 5, 10, 15 and 20% for obtaining good characteristic strength.

The rapid developments of materials, construction technologies and structural systems have given rise to a significant increase of skyscrapers over the past decades. The reduction of the top drifts and base core overturning moments under lateral loads, such as earthquakes and wind loads, has drawn increasing attention in the structural design of super-tall buildings. Outrigger system is considered one of the most effective structural systems to improve the structural lateral stiffness and overall stability, which has been widely used in high-rise buildings. Optimum locations for Installations of outrigger systems can be found. Overall displacements and lateral drift can be reduced. Outrigger systems enhance the stiffness of high rise buildings by the introduction of stiff outriggers at different locations. The effect of outrigger in a setback building is studied. The loads considered are as per IS codes. An Etabs model of 45 storey building is considered for this study. Linear time history analysis has been adopted and data of El-Centro earthquake is used as an input. The different parameters considered are the storey displacement and storey drifts. Effect of adding outriggers to an asymmetrical building is considered.

Over half of India’s territory zone is prone to seismic tremors, and the Indian subcontinent has encountered many earthquakes in the past. This study focuses on the vulnerability assessment of buildings by Rapid Visual Screening (RVS) in selected regions of Tier II city of south India—Coimbatore. The building typologies present in various city regions (normally designated as Corporation wards) and potential seismic vulnerability of buildings in each city region (ward) is determined by RVS methodology. The RVS vulnerability scores obtained for all the wards included in this study are low, indicating that these city regions are potentially vulnerable with substantial to very heavy damages in the event of an earthquake. The outcome of the study is useful in preparing efficient earthquake policies at the local level. Further assessment and strengthening are recommended for the buildings in these selected wards with high seismic hazard.

Concrete is one of the most widely used construction material. Its usage is twice that of steel, wood, plastics and aluminium combined. It provides superior fire resistance compared with wooden construction and gains strength over time. Structures made of concrete can have a long service life. The major drawback in concrete works is that the structures will be heavier. In case of RC beams the strength of concrete lying in and near the neutral axis is not fully utilized. So this unutilized concrete is replaced by light weight plastic balls. This is an alternative to reduce the use of concrete. Plastics offer great resistance against chemicals and solvents. The concrete just above the neutral axis is less stressed where as the concrete below neutral axis serves as a shear transmitting media. Plastic material offers a good bond between concrete layers. The stresses in beams are maximum at top and bottom where as, it is zero at the neutral axis. The cement content can also be decreased by saving the concrete which reduces the greenhouse gaseous emissions. So it is considered as eco-friendly. Specimens of solid RC beam, hollow RC beam and RC beam with plastic balls are casted, tested and made a comparison.

Progressive collapse is one of the most devastating types of building failures, most often leading to costly damages and possible loss of life. To study the effect of failure of columns on the entire structure, 15 storey RC building is considered. The progressive collapse analysis and modelling of the building is done using SAP2000. Linear static and Non-linear static analysis is performed to understand progressive collapse. Comparing the results of linear static and non-linear static it is found that non-linear static procedure for progressive collapse analysis is the more effective method than linear static in which a primary load-bearing structural element is removed and the structural material is allowed to undergo non-linear behaviour.

The water used in concrete plays a vital role in cement hydration, managing workability and durability of structure. The limited availability of drinking water raise the importance of optimizing use of drinking water in concrete construction. Magnetized water is prepared by passing normal water through a magnetic field of 0.6 T, 0.8 T, 1.0 T and 1.2 T. The magnetized water can be considered as an innovative technology to optimize the over usage of drinking water in construction. Magnetized water has a unique ability to break down the water clusters and thereby it enhance properties of concrete mix. The aim of this work is to investigate the effect of magnetized water (0.6 T, 0.8 T, 1.0 T and 1.2 T) on fly ash by weight of cement (fresh and hardened properties).

Production of cement causes environmental problems like global warming due to the release of carbon dioxide. Usage of cement can be reduced by partially replacing cement in concrete with a suitable material. This paper studies the effect of water immersed glass powder and glass fibre mechanical properties of concrete. Cement is partially replaced with 10, 15 and 20% of glass powder by weight of cement immersed in water at 1.5, 3, 4.5 and 6 h. Glass powder is added to the water required for the mix before adding it to the cement and aggregates. Then 0.25, 0.5, 0.75 and 1% glass fibre by weight of cement is incorporated in to the concrete containing optimum percentage of glass powder with optimum immersion time. Glass fibre having length of 6 mm and diameter 14 µm is used. Calcium and sodium ions are dissolved in presence of water from glass powder (Abo-Hasseira et al. in Constr Build Mater 206:674–682, 2019 [1]; Elaqra et al. in Constr Build Mater 203:75–82, 2019 [5]). Concentration of sodium ions decreases with immersion time as it bonds with silicon dioxide on the surface of glass powder particles (Abo-Hasseira et al. in Constr Build Mater 206:674–682, 2019 [1]). This paper discusses compressive strength, flexural strength and split tensile strength of concrete. Higher strength is obtained due to the packing filling effect of glass powder and pozzolanic reaction due to the free ions in water before mixing with the concrete.

The concrete’s workability is divided into three phases namely coarse aggregate phase, mortar phase and cement paste phase. The coarse aggregate phase comprises of coarse aggregate and mortar phase. The mortar phase of concrete primarily comprises of binder, fine aggregate and water. The function of mortar phase is to impart workability to the concrete. Holistically, factors like water content, shape of aggregates and gradation of aggregates plays an important role in regulating the workability of mortar. However, there is no such methodology established from which one can predict the workability of concrete based on the texture and shape parameters of aggregates. To study the relation of above-mentioned factors on the workability, tests were carried out using uniformly graded and well graded Natural sand and Manufactured sand for assessment of shape parameters and workability. The shape parameters of fine aggregates were obtained through Digital Image Processing (DIP) method which was conducted on at least 600 individual particles from each grade of both samples. The workability of cement mortar for both the samples are tested at water-cement ratios (0.3, 0.35, 0.40, 0.45, 0.5) and cement-sand ratios (1:1, 1:2, 1:3, 1:4). Mini flow table test was used to check workability in terms of its average flow. From the experimental results a relationship is developed, which states that the average flow of zone sand is proportional to the weighted average of the product of the average flow of the mortar for a particular sieve class, at its corresponding W/C and C/S ratio, and proportion in the given sand sample. The proposed equation to predict the workability of cement mortar is validated using test results.

In our country, the marble and granite stone processing is one of the most flourishing industries, in which around 25% of the original stone mass is left out in the form of dust during the cutting and polishing process. Both of these dusts are settled down by sedimentation and then directly disposed as waste materials which will create a serious threat to an environment. This paper highlights the effective utilization of these waste materials in the concrete production, since their composition is most favourable for the replacement of cementitious materials. In this paper, the both waste materials are utilized individually as a replacement for cement in the varying proportions ranging from 0 to 30% to study the sulphate resistance property. For this study, the mortar cube specimens of 70 mm × 70 mm × 70 mm are prepared and immersed in MgSO4 and Na2SO4 solution for a period of 28 days. With the detrimental factor of the compressive strength, the optimum replacement of these waste materials on the cement content is arrived individually and the results are compared among each other.

Many researches has been carried out regarding the possible reuse of the waste materials like marble and granite powder in a economical and eco-friendly manner. The use of marble and granite products waste is identified as a substitute to cement in mortar mix to an option that come up with concrete products in a cheaper cost in the construction industry. In the sustainable point of view, an experimental study is conducted on the cement mortar with the replacement ratio of 0%, 5%, 10%, 15%, 20%, 25% and 30% of marble powder and granite powder in the cement content to examine the durability properties. For this durability study, the mortar disc specimens of dimensions 80 mm × 50 mm are prepared, cured for a period of 28 days and tested for rapid chloride permeability test. The experimental results are showing that the granite powder replaced mortar is moderately better than marble powder replaced mortar. The optimum replacement is found as 5% for marble dust and 10% for granite powder, since the penetration is low based on the experimental results.

Light weight concrete (LWC) has been successfully used since the ancient roman times and it has gained its popularity due to its lower density and superior insulation properties. Compared to the conventional concrete, LWC can significantly reduce the dead load of structural elements, which makes it especially attractive in the construction of multi-storey buildings. The materials used for preparing the light weight concrete is pumice stones, burnt waste material ash and GGBS. The coarse aggregates are partially replaced with pumice stones in the varying fractions of 10%, 20% and 30%. The cement are partially replaced with waste burnt ash in the proportions of 5%, 10% and 15%. Additionally 5% GGBS is introduced into that mix proportions. It is observed that by the optimum presence of light weight aggregates such as 15% of burnt ash and 30% of pumice stone, density of the concrete is reduced upto 2140 kg/m3. In the same time the compressive strength is achieved around 75% to 81% of the strength of the conventional concrete. Analytical equations models are arrived from LabVIEW software and it has been well correlated the experimental test results with the deviation of $$\pm$$ ± 20%.

Functionally graded materials are an advanced class of composite materials characterized by spatially varying properties and are designed to optimize the performance through the distribution of the desired property. A functionally graded material eliminates the sharp interface between dissimilar materials and possesses a gradual variation from one material to other. The research in this area is still in nascent stage. It has many promising applications in different fields like biomedical, defence, structural engineering etc. As compared to the conventional homogeneous, isotropic materials these are complex in the analysis and design procedures. This paper presents a critical review on the mechanics and behaviour of the functionally graded materials towards their applications in structural engineering, specifically in the design of protective structures. Besides this, a brief description is also provided with suitable formulations regarding the gradation of the properties in a particular direction to achieve the desired functionality.

Utilization of recycled concrete aggregates as an alternative material for natural aggregates in concrete have been of greater importance due to its disposal problems followed by the problem on scarcity in construction materials namely aggregates. This paper presents a study on the mechanical properties of concrete manufactured with recycled aggregates collected from a 10 year old demolished building at the institute. Recycled aggregates were immersed in water for 24 h before its utilization in concrete to achieve surface saturated dry density. A total of 8 batches of Recycled Aggregate Concrete and 2 batches of Normal Aggregate Concrete under different replacement levels of 0%, 10%, 20%, 30% and 40% and at two w/c ratios of 0.45 and 0.5 were manufactured. Various parametric tests such as compressive strength, split tensile strength, flexural strength and elastic modulus were performed to study its mechanical properties at the age of 7 days and 28 days. Results indicate that the mechanical properties of RAC was greatly influenced by the w/c ratio as the pre-saturation of recycled aggregates for 24 h prior to manufacturing yielded better strength even at 0.45w/c ratio and at 30% replacement.

Rigid pavements need overlays for their rehabilitation, which are constituted of fine materials and fibres. The present study is focused on yielding overlays made of engineered cementitious composite containing polypropylene (PP) fibres and high volume fly ash. Scrap rubber has been used as a replacement of fine aggregates @ 10, 20, 30 per cent for improving the straining tendency and bending ability of concrete. The strength of 40 MPa has been targeted. Since the composite is made up of fine materials, therefore the durability has been evaluated in terms of rapid chloride ion penetration and not permeability. This test measures the diffusion capacity of rainwater containing chlorides into the concrete which indicates the corrosion potential of continuous reinforcement. It was found that a composite having fly ash/cement ratio 1.2/1, along with 1.5% polypropylene fibre reinforcement (vol./vol. of concrete) shows a minimal reduction in compressive strength i.e. up to 25 per cent on 30 per cent w/w replacement of fine aggregates with powder scrap rubber but the main aspect is that the diffusion rate shows appreciable decrement with an increase in fine rubber content when compared with the 4 m MPa normal mix which ensures lesser chance of corrosion in reinforcement at joints.

The fatigue failure of structural elements subjected to repeated cyclic loading may reduce the life of infrastructures. Heterogeneous nature of concrete and random factors in fatigue testing lead to great variability in fatigue life of concrete. As deterministic approach depends on certain parameters and initial conditions, it is not reliable for the prediction of fatigue life of concrete. In this study, a probabilistic approach using artificial neural network is utilised to predict the fatigue life of plain concrete. An artificial neural network predictive model was developed utilising the data from fatigue tests conducted on plain concrete beams of three different sizes mainly small, medium and large. The model is trained using the available experimental data of small and medium specimen and is validated using available experimental data reported on large specimens. The developed model is able to predict the number of cycles of failure of concrete by considering material and fracture mechanics properties responsible for the softening behavior of concrete as input. This approach is advantageous over other methods as it includes the randomness in the fatigue of concrete and will be able to predict the fatigue life of concrete with reasonable accuracy.

Convergence of mesh size is vital in Finite Element Analysis (FEA). It helps the user procure better results and hence enables the user to rely on the FEA model results. FEA models are beneficial in reducing the cost of studies that are otherwise not feasible with experimental models. It allows a faster design of the models in the required studies. However, only after the mesh convergence study, results of the FEA models are considered as fit, accompanied by adequate material models, boundary conditions, loading provided to the model. For validation, experimental literature chosen as such that a steel impactor hits a Reinforced-Concrete (RC) beam-column joint with an absolute velocity at the beam free end. This present model, validated on various parameters like the displacement of the beam and residual velocity of the structure after the impactor has hit the structure. This paper has attempted to converge the mesh size of RC beam-column joint experimental models from the literature, and hence set a mesh size fit to simulate other such models.

To meet the current expeditious work pace, innovative modus like 3D concrete printing will be useful in bridging sustainability in material usage with cost and time efficiency along with overcoming labor constraints. This preliminary study was aimed at partial replacement of 53 grade Ordinary Portland Cement (OPC) with Flyash (FA), Silica Fume (SF) and Ground Granulated Blast Furnace Slag (GGBS) in the preparation of mixes. The replacement percentages were decided based on literature review and preliminary trials. The fine aggregate of particle size in the range 1.18–2.36 mm was used as fillers. The required workability for printing (based on trials) was achieved by using minimal dosages of a PCE based superplasticizer. The extrudability of mixes was tested with a simple mortar grouting applicator. The addition of 0.1% percentage of Polyvinyl Alcohol (PVA) fibre resulted in a better finish of the printed layer. The study is focused on the fresh and hardened state properties of printable cementitious mixes. The test results indicate that the mix containing GGBS, FA and fibre had better printability, good interlayer bonding, reduced gap time, and increased flexural and compressive strengths.

Due to architectural compulsions, buildings invite various types of irregularities due to which seismic performance of them is highly affected. With increase in such type of buildings, it is important to know the extent to which an irregularity could be introduced without causing any major damage to the structure. Different kinds of Irregularity indices are used by many previous studies for quantifying the vertical irregularities in buildings. This study discusses about the previous irregularity indicators and an attempt is made to evaluate their effectiveness to predict the seismic risk of irregular buildings. Steel buildings having various kinds of vertical irregularities such as mass, stiffness and/or strength are considered in this study and their seismic risks is evaluated. Pearson r correlation methodology is considered for correlating the irregularity indicators and the associated seismic risks and conclusions are drawn from them.

The rheology deals with flow of matter. It changes with respect to the material composition and test condition. This work investigate the influence of dosage and family of superplasticizer and dosage of mineral admixture and effect of temperature on the rheological properties of cement paste. For this purpose cement pastes were prepared at a water cement ratio of 0.37 using OPC cement, different percentage of fly ash(15, 25, 35) and different dosages of superplasticizer (one from each family). Rheological tests were carried out using co axial cylinder viscometer at three different temperature (15, 27, 35 °C). Rheological parameters like yield stress and plastic viscosities were calculated using Bingham and Herschel bulkley model. Rheological performance were modeled using Multilayer Perceptrons in Tensorflow. Out of 252 data generated, 204 data is used for training the model. The input parameters consists of variables like dosage of cement, fly ash, water, four families of super plasticizers and three different temperatures. The output consists of the measured value of yield stress and plastic viscosity of cement paste. Accuracy of the model is tested using 48 data set. From the predicted data it is clear that the python can be used effectively to predict the rheological properties (yield stress and plastic viscosity) of cement paste.

Steel bridge girders are very common in marine or offshore structures. In such salty conditions chance of formation of pitting corrosion is high and the failure due to pitting is observed to be catastrophic. Steel girders with corrugated web can be widely used as bridge girders due to its out of plane buckling strength and also the number of stiffeners can be minimised compared to plane web. Since the failure due to pitting corrosion mainly occurs at supports, assessment of shear buckling strength is very much important. In this study shear strength of corrugated web with artificial corrosion pits numerically computed by varying corrosion volume and position. Failure patterns and the behaviour was investigated. The critical buckling load was found to be decreased while increasing the volume ratio. In the case of specimens with same volume ratio corrosion position has a significant role in assessment of shear strength of the specimen.

The Octagonal concrete filled steel tubular (CFST) sections offer greater efficiency than square and rectangular tubular sections because of their better local-buckling resistance and flat surfaces that allow easier connection construction compared with circular tubular sections. This paper presents analytical studies on the seismic behavior of steel I-beam to octagonal CFST column assemblies with external diaphragms. Different stiffeners, slenderness ratios and moment capacities were introduced in the external and corner octagonal column-beam model and studied analytically using the software ANSYS 16.1. In the analytical study finite element models are developed to predict the hysteretic behavior and the stress distribution. Steel to concrete interfaces are modelled by hard contact with friction. The loading condition is displacement controlled and the axial load is applied on the top of the column and lateral load is applied on the column by cyclic vertical load on the beam ends. The stress distribution of model components, including steel beams, steel tubes, stiffeners and concrete cores are illustrated. The results indicate that failure modes have significant effects on the characteristic of stress distribution.

Fiber reinforce concrete (FRC) has been in use for more than 50 years now. The conventional concrete is generally weak in tension, has low tensile strain capacity, and is brittle in nature, whereas, fiber reinforced concrete containing fibrous materials enrich the tensile and bending performance of concrete. Here concrete is prepared by adding PET bottle strips as fiber which may help to reuse the plastics and to reduce environmental pollution. Incorporating plastic fiber in concrete increases both the tensile strength as well as durability. The strength requirement of plastic fiber reinforced concrete (at 0.5%, 1%, 1.5% by weight of binder content) can be improved by adding supplementary cementitious materials at 10%, 20%, 30% and 40% by weight of cement. A comparative study of fiber reinforced concrete with different mineral admixtures such as Rice Husk Ash (RHA), Ground Granulated Blast-furnace slag (GGBS)and Metakaolin (MK) in optimum percentage was considered. In this work the physical and mechanical behaviour of PET fiber reinforced concrete with various mineral admixture were studied.

The behavior of segmental structures depends mainly on the behavior of the joints between the segments. Even though joints forms a discontinuity; they should have the capacity to transmit compressive and shear stresses. Shear behavior of the joints is greatly influenced by the confining pressure and the surface properties. According to shear friction approach, shear capacity of joints can be improved by varying the surface properties of joints. It is observed that limited studies were done on the factors affecting the friction at joints and only few Finite Element studies on joints were done. In this study, a three-dimensional Finite Element study using ABAQUS has being carried out on joints with various surface properties. The Finite Element Analysis model consisted of two parts in surface to surface contact. The C3D8R element and B31 element with a refined mesh size of 10 mm is used for modelling concrete and reinforcement respectively. The material properties considered were modulus of elasticity of 27.38 GPa and Poisson’s ratio of 0.2 for concrete and for reinforcement steel were Young’s Modulus 210 GPa and poisson’s ratio 0.3. Material nonlinearity is introduced by Concrete Damage Plasticity model. Parameters studied are prestressing force and coefficient of friction at joints. The shear resistance of joints under different surface properties were evaluated using FE study and compared with experimental results available from a reported literature (Jiang et al in Mech Comput 19(1):1–16 2015, [1]).

The use of cold-formed steel structures has increased in recent years, and some built-up section members are also widely used for their excellent structural behaviors. The stainless steel is not a single material but it is a family of corrosion resistant steel. The Lean Duplex Stainless Steel (LDSS), which is a category of stainless steel is becoming popular as a structural member because of its increased corrosion resistance and durability compared with that of steel. When compared to other construction materials, the LDSS has many unique properties that are advantageous not only from a corrosion view point, but from a strength and safety viewpoint as well. These LDSS may be used as primary structures for compression members of trusses or built-up columns due to varieties of advantages such as high strength to weight ratio, ease of fabrication, no need of protective coatings and they can be fully recycled after a useful life. This study presents an investigation on the LDSS built-up columns of rectangular, I, T and Z shaped sections under the axial loading and eccentric loading for various eccentricities. The finite element models of LDSS built-up columns are developed using ANSYS 16.1 WORKBENCH in order to investigate the behavior of various built-up columns at axial loading and eccentric loading. This study considers the eccentric loadings at 25, 50 and 75% eccentricities of the rectangular, I, T and Z shaped LDSS built-up columns.

In the cement industry, the use of pozzolanic materials is attaining paramount interest due to their beneficial effect on various properties of cement. Many type of cement have been developed in the last two decades to meet specific requirements. Ternary cement is one such type of modern cement, which consists of two pozzolanic materials with ordinary clinker. Blending reduces overall clinker content in cement. Ternary cement saves cost, resources and energy. Further, they reduce emissions & wastage of raw materials. Partially replacing clinker by calcined clay combined with limestone can be adopted to achieve blended cement with good performance. Higher levels of clinker substitution up to 50% are possible with 30% calcined clay, 15% lime stone and 5% gypsum, which contribute to reduction of CO2 emission associated with cement production. Previous studies on such replacements and how they were beneficial for sustainable development are summarized in this review paper.

Masonry infill walls are commonly used as external walls and partition walls in RC frame buildings. RC frames in earthquake regions are usually designed with higher ductility and hence undergo large displacements under horizontal loading which lead to a rapid activation of the significantly stiffer infills. This activation generates an undesired interaction between the frame and the infill resulting in the participation of the masonry infills for load transfer. The seismic performance of masonry infill walls under earthquake loading have been studied experimentally and analytically. Damages under in-plane loading are found to escalate the out-of plane response. Over the years the studies have been extended from steel frames to RC frames and the infill materials have been varied from masonry infill to concrete panels. However, the studies are particularly focused on masonry infill units. With the rising concern for environmental pollution control, alternative green materials are also being recommended as infills. This paper presents a review on the techniques that have been developed to improve the seismic performance of infilled frames. It can be achieved by providing a rigid connection between the infill and the frame or by completely isolating the infill walls from the surrounding frame and by using seismic isolation elements.

Nowadays high-rise buildings and multi-storey buildings are more common and popular, they require highly strong and efficient structural system. Concrete Filled Steel Tube [CFST] are capable of providing the same. Many innovative ideas are being put forward in the improvement of the CFST section, which resulted in better improvisation of their column behaviors. Diagonal rib stiffened square concrete filled steel tube can increase the confinement, load-carrying capacity and ductility compared with the CFST specimens without stiffeners. By introducing the diagonal rib fitting, the composite effect of the square concrete filled steel can be improved, which is proved from the previously conducted experiments by several researchers on CFST sections. By analyzing the test results from experiments, a cost effective, robust and safe designed cross section is developed. The development of an analytical model for the CFST with diagonal ribs for predicting their axial load carrying capacities was done by finite element analysis method. It helps in predicting the results of combinations made by using various parameters.

During earthquakes, adjacent structures may collide with each other due to different dynamic characteristics. When buildings vibrate out-of-phase and the separation gap provided between buildings is not sufficient to accommodate their relative motions, collisions can cause severe damage or even complete collapse of structures, and is known as seismic pounding. In metropolitan cities, due to increased population and land values, buildings have been constructed with inadequate separation distance between them. The seismic oscillations induced in a structure in a block of buildings will be partly restrained in lateral displacements and hence torsional movements are introduced (asymmetric pounding). Two different types of impacts may occur during pounding including floor-to-floor and floor-to-column (inter-storey) collisions. In this paper, the effects of asymmetric (contact asymmetry) pounding on the seismic response of adjacent buildings with symmetric plan and unequal building heights are studied. Time history analysis of adjacent buildings with different pounding cases involving 1, 2 and 3 column pounding is carried out using the software ETABS and the corresponding torsional response is evaluated. The influence of separation gap and floor heights between the adjacent structures on the torsion effect is investigated and the results are compared with no pounding case.

Self-cured recycled aggregate concrete with shrinkage reducing admixtures is one of the pioneering researches in the construction industry. There is a possibility of depletion of natural resources due to prolonged consumption over a period of time in our modern civilization. In this research, characteristics of recycled aggregate concrete with supplementary cementitious materials (SCM) like powdered limestone and fly ash with self-curing agent PEG6000 were investigated along with the conventional concrete. Hydration plays a predominant role in the properties of hardened concrete. Particularly in high strength concretes, micro cracking occurs due to the absence of pore water and lack of relative humidity thus causes self-desiccation. The experimental studies exhibit the performance of concrete mixes with 35% limestone powder in LP60 and 35% fly ash in SC60 and RA60. The mechanical and durability properties of M60 concretes with SCM’s and PEG6000 were investigated. The results indicated that concretes with 1% self-curing compound shows improved results than the mixes with 0%. All the concretes mixes achieve the properties at the range of self-compacting concrete in the green state.

The people of Kerala state experienced extreme hardship and unmitigated misery in the year 2018 and 2019 during the month of August. The fury nature of rainfall caused floods and various negative impacts on structures, thereby truncating durability of structures. Some of them were completely destroyed and some required proper maintenance. This paper depicts the strength and hydrophobic characteristics of concrete, developed by partial replacement of cement with stearic acid treated metakaolin. The results showed better properties than normal concrete.

With the addition of different pozzolanic cementitious materials, an air entrained concrete shows different behavior in terms of durability and compressive strength. The amount of entrapped air is reduced when fly Ash is used in air entrained concrete. The resulting volume of air decreased appreciably with increasing silica-fume content in air entrained concrete. This paper has focused on the effect of replacement of coal bottom ash (CBA) as a fine aggregate in the air entrained concrete in the presence of different pozzolanic cementitious materials and it compares the different properties with the normal concrete. Experimental work shows that CBA causes a reduction in 7 days compressive strength appreciably @ 50% natural fine aggregate (NFA) replacement in comparison to that at 25%. Beyond 7 days curing CBA starts acting as a Pozzolan and there is not much strength decrement in mixes with 50% NFA replacement. Also, this replacement level mitigate the effect of reduction in air entrainment caused by fine mineral admixtures in wet state thereby increasing the air entrainment capacity of concrete. Hence it was concluded that if we increase the content of Coal Bottom Ash up to 50% then it will be beneficial for air entrained concrete production.

Concrete curing is one of the most critical process to obtain the desired concrete properties. The traditional method of curing is achieved by wetting the exposed surface and preventing concrete from losing moisture. However when the mineral admixtures are applied to concrete, the demand for curing water will be much greater than that in a ordinary Portland cement concrete. If this water is not readily available, it can result in significant autogenous deformation and cracking. In order to overcome these draw back the attention is focused on advanced technology in curing i.e., self-cuing concrete. Self-curing or internal curing is a technique in which no additional water is required to enhance the rate of hydration. These self-curing concretes are also weak in resisting tensile forces, but by incorporating fibers on self-curing concrete both the tensile strength as well as the durability can be increased. In this study, self-curing concrete is achieved by incorporating Polyethylene Glycol (PEG-400) at different dosage (0.5, 1, 1.5 and 2%) by weight of binder content of M40 grade of concrete. To its optimum dosage the hooked end steel fibres are added to this self-curing concrete at different percentage (0.5, 1, 1.5, and 2%) by volume of concrete. The optimum steel fibre content is then determined with respect to strength parameters. The strength properties of self-curing concrete with steel fibers is then compared to that of conventional concrete and self curing concrete.

Safety in construction is crucial to avoid fatal accidents. To enhance safety in construction sites it is necessary to recognize the causes of accidents and take proper measures. It is necessary to make workers aware of such hazards which is possible through trainings, meetings, toolbox talks, communication among workers etc. Indian construction sites which have a diverse language speaking work force will have difficulty in communicating efficiently. This paper tries to identify the major causes of accidents in construction sites and to analyse the communication patterns of the workforce using Social Network Analysis (SNA) in the construction sites of Chennai. The study also measures the safety performance of the workforce and compare it with the network characteristics identified through SNA. The study would thus help to recognize all the safety issues and to measure the current safety condition of the Indian construction Industry

Pavement quality self-compacting concrete (PQSCC) incorporating ground granulated blast furnace slag (GGBS), flyash and silica fume has been investigated for early strength development, for various curing conditions. After being tested for workability befitting that of a SCC, the concrete mixes were tested for strength. Three different curing regimes considered are: normal water curing (23 °C), hot water curing at 40 °C, and steam curing at 60 °C. For making the curing procedure possible at site, least possible curing duration was chosen i.e. 8 h per day (2 h after each 4-hour cycle). CaCl2 was also added in permissible limits (1.5% by weight of binding material) to compare the strength gain. Test results indicate that amongst the three curing regimes, steam curing performs well even without CaCl2 incorporation whereas hot water curing must be complemented with CaCl2 to achieve high strength. Both GGBS and flyash based composites perform better with special curing measures but flyash based composites performed much better in presence of CaCl2 accelerator whereas flyash composites need steam curing. These improvements are attributed to two main factors: mix design of pavement quality SCC on basis of combination of high packing density theory and Okamura and Ozawa method, and application of special curing procedure which is subjective to different pozzolans.

Public Private Partnership (PPP) was introduced in India as a viable project implementation mechanism to meet the growing demand for new and better infrastructure services. Rise of non-performing assets accompanied by high risk at various stages of PPP made government adopt Engineering, procurement, and construction (EPC) contracts. Based on poor performance and failing to meet the deliverables of EPC projects, a Hybrid model based on PPP and EPC is necessary. In this study failure factors in PPP and EPC projects is identified, analyzed and ranked using multivariate factor analysis and Delphi technique. To develop a Hybrid model, a systematic research approach (literature review and interviews with experts and experienced practitioners) has been taken to understand infrastructure projects. The findings can be used to create a Hybrid model obtained by eliminating highly occurring failure factors in EPC and PPP projects in India.

With an increased demand for public works projects, there is a need to focus attention on the efficient delivery of construction project services in the public sector and in particular municipal project delivery. This includes a broad category of infrastructure projects financed and constructed by the local self-government for uses in the greater community. These type of projects have special challenges that may differ from other construction projects. A decision—making process known as AHP (analytical hierarchy process) was used to identify and prioritize the various parameters affecting performance in LSGD projects. A comparison—based survey is conducted to quantify relative priorities for a given set of alternatives on a ratio scale based on the judgment of the construction professional's experience. Through the AHP model, various parameters, as well as improved techniques, are identified to reach the optimum goal of performance improvement.

This paper mainly deals with the prevention of flutter instability in fin with shroud of a typical Rocket body through parametric studies. Flutter is an aeroelastic instability which occurs when aerodynamic loads cause deformation of the body which in turn initiates an oscillation in the body and further interacts with aerodynamics. The crew escape system is an emergency escape structure designed to swiftly pull the crew module along with the astronauts to a secure distance from the launch vehicle during launch abort. For the control of crew escape system during the ascent phase of trajectory, sweep back fins are used at the bottom of the vehicle. Finite element modelling of the fin was done using MSC/PATRAN software. Flutter analysis is carried out in MSC/NASTRAN using in-built aerodynamics. MSC/NASTRAN uses plate theories such as Doublet Lattice Method for subsonic Mach number, ZONA51 for transonic and low supersonic Mach numbers and Piston theory for high supersonic Mach numbers to generate the aerodynamic force within NASTRAN. MSC/PATRAN is a software developed to provide a systematic approach towards making finite element modeling fast and accurate; MSC/NASTRAN is a general purpose finite element analysis computer program that addresses a wide range of engineering problem and is also capable to focus on particular types of analysis. In this work, initially normal mode analysis was carried out for the modeled fin and flutter analysis was performed. It was observed that flutter instability occurred in most of the Mach numbers. In order to prevent flutter, the method of mass redistribution is adopted. Mass addition is carried out on leading edge and trailing edge to see the effect of movement of C.G with respect to the shaft axis. By carrying out various mass redistribution studies, the flutter instability in the fin is alleviated. This effort will be helpful for flutter prevention in control surfaces of upcoming vehicles also.

Pipeline networks are responsible for transporting vital materials such as water, oil and gas. Complicated loads, material aging, environmental corrosion, and vibration fatigue are the factors which may cause structural deteriorations of pipelines during the life cycle service because of which leaks may arises. Any leakage in the pipeline system can cause major financial losses and possible environmental damages. Currently, buried pipelines are only monitored at key points, which can be spaced several kilometers apart. The use of these discrete sensors for large pipelines is simply impracticable and not cost effective. Distributed fiber optic sensing offers the ability to measure temperatures and strains at thousands of points along a single fiber. DSTS-BOTDA (Distributed Strain and Temperature Sensor-Brillouin Optical Time Domain Analysis) utilizes “stimulated” Brillouin scattering while a DSTS-BOTDR (Distributed Strain and Temperature Sensor-Brillouin Optical Time Domain Reflectometer) utilizes “spontaneous” Brillouin scattering. In this paper, experimental investigations carried out using distributed fiber optic sensing for leakage identification in pipelines is presented. Two different kinds of sensors were used for monitoring strain and temperature variations during leakage. The methodology adopted for instrumentation and the results obtained are presented in detail in this paper.

Geopolymer concrete technology is a promising technology for the construction industry. Replacing the conventional resource consuming Portland cement with supplementary cementitious material can reduce the carbondioxide emission as well as energy consumption. It serves as an effective way of disposing industrial wastes that found difficult to be handled in past. Rice husk ash, an agricultural biomass which is rich in silica can be used as an effective source material. In the present study M30 grade GGBS and rice husk ash based geopolymer concrete is developed. Rice husk ash of varying percentage of 5 and 15% is considered to study its effect on mechanical and durability properties. 6 M sodium hydroxide is used. Ratio of sodium hydroxide to sodium silicate used is 1:2. Ambient curing of 28 days is done. The result is compared with OPC concrete specimen to evaluate the performance of geopolymer concrete.

In this study, the response of brick masonry specimen subjected to vertical load is analytically calculated using existing formulas and numerically investigated using a popular software ABAQUS. The brick masonry specimen is a small part of the old building which was constructed with brick masonry was taken for analytical and numerical investigation purpose. It consists of three layers of brick and two layers of mortar. The height, width and thickness of the specimen is 245 mm, 220 mm, and 100 mm respectively. Macro and micro model of the specimen was developed using ABAQUS software. The material model used is elastic plastic model C3D8R. Vertical load from 0 to 30.0 kN at interval of 3.0 kN was applied on the specimen. It is very difficult to study the behaviour of brick and mortar together and separately of brick masonry considering the effect of continuity of materials at the joints between brick and mortar. To study the behaviour, macro and micro models are developed and tested upto design load. From the macro and micro models, deflections and strains of brick and mortar upto design load were predicted and these values were compared with analytical calculations. It was found from the investigation, that the increase in strains and deflections are almost proportional to the applied loads.

Earthquake damage assessment studies conducted throughout the world have already established the importance of considering the contribution of reinforced concrete infilled frames in the response of structures subjected to sudden lateral loads. Still, much clarity needs to be made on the behaviour, and failure mechanisms of RC infilled frames when subjected to such large and sudden earthquake loads. A data-driven machine learning approach to the prediction of failure modes of RC infilled frames is suggested in this paper. An exhaustive database consisting of experimental results done throughout the world was gathered. A failure mode classification system consisting of three predominant failure modes is proposed. Suitable parameters are identified for the purpose of machine learning modelling. Machine learning algorithms like AdaBoost, CatBoost, KNN, Decision Trees were used to predict the failure modes. An open-source dynamic model is created, which could be updated once new data is available from experiments. Google provides a free TensorFlow enabled Jupyter notebook for machine learning (Google Colabs). The same was used in this study as it supports remote access from different locations, and the model would always remain in the cloud, making it instantly accessible. Three performance measures were used in this study to evaluate the performance of the various machine learning models: accuracy, precision, and recall. The results obtained indicate that for complex structural interaction problems having (a number of dependent parameters) machine learning modelling techniques, in which the dataset is allowed to speak for itself, can be successfully employed.

The main objective of this study is the strengthening of flat slabs against punching shear with an experimental model. The flat slab strengthens by a newly introduced method, named as grooving method (GM), was utilized in the present study. The groove provided in two orthogonal directions (x and y axes) of slab plan and then mounting the external FRP bar in one direction and FRP strip on another direction in EBROG (externally bonded reinforcement on groove) method. For this purpose, 700 × 700 × 100 mm dimensions slab was tested under concentrated loading. The slabs were tested for ultimate load and deformation after curing for 28 days. The experimental results showed that the EBROG method with FRP enhanced the strength of flat slab against punching shear with great efficiency, and punching shear capacity of strengthened samples increased between 28 and 58% compared to control one. Hence this is a highly innovative practice that can be implemented in the construction industry as the method is high efficiency and the environment-friendly

Copper slag is one of the discarded material that is found to be having a better scope in concrete technology as an alternate for the river sand. Studies show that substituting copper slag partially for the sand leads to the bleeding which further affects the performance of the concrete. In this paper the mineral admixtures such as fly ash and Ground Granulated Blast furnace Slag (GGBS) were added to the concrete containing fine aggregates which is partially substituted with copper slag. An attempt is made to bring down the concrete bleeding and enhance the performance of the Copper slag incorporated concrete. Fly ash and GGBS were chosen mainly based on their global environmental sustainability, cost and durability qualities. Test experiments were designed using Response Surface Method (RSM) to obtain the various trial proportions. Three factors such as Copper Slag, GGBS, and Fly Ash are considered. Three levels of partial replacement are considered for each factor. The levels were 20, 30, and 40% for copper slag; 20, 35, and 50% for GGBS; and 15, 25, and 35% for Fly ash. Test were performed on each trial proportion to study the compressive strength, split tensile strength, chloride penetration and sorptivity properties. The results show that there is considerable improvement in the performance of the copper slag concrete at the optimum dosage of GGBS and fly ash.

Reinforced concrete (RC) structures and the structural elements (beams, columns, slabs) undergo degradation in strength and stiffness, when exposed to high temperature in the event of a fire breaking out in such structures. The concrete column elements tend to support the compressive loads transferred onto it from the floors and maintain the stability of the structure. The degradation in the compressive strength of concrete and degradation of yield strength of reinforcing steel present in the RC columns that get exposed to high temperature, in the event of a fire causes instability or collapse of the entire structure. In this work the variation of temperature across the cross section of reinforced concrete (RC) columns having various sizes and shapes (square and rectangular) exposed to different high temperatures (475 and 625 °C) and time of exposure (1 and 3 h) has been studied by carrying out a heat transfer analysis in Abaqus. The heat transfer analysis is carried out using heat transfer elements that possess the thermal properties of the materials (concrete and steel) that are temperature dependent. The depth of variation of a particular temperature for a particular time of exposure from the outer surface of the RC column upto the core having a particular size and shape is assessed. It is inferred from the analysis results, the time taken for a particular temperature to reach upto the core of the RC column is related to the size and shape of the concrete column. It is also learnt from the results, apart from increasing the concrete cover, a particular optimum size of a concrete column in cross section is necessarily to be provided while designing the column from thermal resistance point of view. As this optimum size of the column would delay the temperature reaching the core for a particular time of temperature exposure and would maintain a certain portion of concrete around the core portion to retain its original strength without causing failure of the column before the fire is put off.

The rapid growth of urban population and the limitation of available land, taller structures are preferred for sustainability. When the height of the structure increases, the consideration of lateral load becomes critical and the lateral load resisting system becomes more important than the structural system that resists the gravitational loads. Diagrid structural system is widely used for tall buildings due to its structural efficiency and aesthetic potential provided by the unique geometric configuration of the system. In this paper, the impacts of variation of the angle of tilting on steel diagrid structures are presented. Modal and time history analysis of three, six and nine-storey buildings with a base dimension of 36 m × 36 m is performed using ETABS 2016. The results in terms of the time period, undamped natural frequency, maximum storey displacement, maximum storey drift, storey shear and overturning moment are compared. Tilted 3 storey diagrid building was found to have lateral stiffness very much similar to that of a prismatic diagrid. While the lateral stiffness of 6 storeys and 9 storey tilted buildings up to 2° was found to be similar to that of prismatic diagrid building.

Excessive utilization of natural resources and dumping of waste materials aggravates environmental degradation. Utilization of a locally available industrial waste facing disposal issues—Jarofix as fine aggregate replacement in concrete building blocks is investigated through this research. Test results justify the potential of jarofix for replacement of fine aggregate up to 30% in concrete building blocks with improved strength characteristics. Test on structural masonry verify the suitability of these blocks over conventional concrete blocks.