Advances in Structural Engineering and Rehabilitation

Lateral load capacity of any structure plays a very important role to resist earthquake [1]. To understand the lateral load capacity of any low-rise masonry building, a 3D finite element model of unconfined brick masonry stack has been drawn here. The ANSYS modeling of plain brick masonry shows that masonry structure fails at the joint. Therefore, to impart ductility and strength in the stack, shear key of 4 mm diameter TMT bar of 1/8th, 1/6th, and 1/4th of longitudinal length of brick length is provided at every joint separately in different samples and performance of both confined and unconfined prism is tested against vertical and horizontal load [2]. The purpose of this study was to develop a better behavior of low-rise masonry building during earthquake. Numerical as well as experimental methods have been adapted to calculate the stress developed in masonry stack [3].

The frequency of the occurrence of earthquake has risen in the last decade and the casualties with low-rise structure, especially unconfined structure, were very high in comparison to reinforced concrete structure worldwide. In this study, the behaviour of confined building in lateral load has investigated. A confined building model has been constructed in the laboratory with the help of scaled bricks, mortar and reinforcement. The building model is tested on shake table under external excitation force of different magnitudes and frequencies. With the help of PULSE Labshop, the values of displacement, velocity and acceleration are measured at different locations of model. The response of the four-storey building model is measured and presented, and the response of the building is analysed under harmonic vibration.

The present paper deals with thermal uncertainty quantification in the free vibration of functionally graded materials (FGMs) cantilever plate by using the finite element method coupled with multivariate adaptive regression splines surrogate (MARS) model. The combined effects of uncertainty in material properties on the natural frequency are examined. The power law is employed for gradation of material properties across the depth of FGM plate, while the Touloukian model is used to evaluate temperature effects on the material properties. In finite element analysis (FEA), eight noded iso-parametric elements are considered with each element having five degrees of freedoms. In MARS, Sobol sampling is employed to train the model, which results in better convergence and accuracy. The results of MARS model are validated with Monte Carlo simulation results. The results reveal that MARS model can achieve a significant level of accuracy without compromising the accuracy of results.

The predictable growth in economic actions during the twenty-first century is very huge in construction and in transportation. With the increase in population and globalization, there is very less land available for construction purposes; thus, the need of high-rise buildings which are capable enough to resist seismic forces is of much importance. Designing the members of such a high-rise building is being very repetitive and time-consuming, so the concepts of MACROS are widely used for design purposes and can easily eliminate these disadvantages. In this project, the structure is first analyzed by using STAAD Pro and members of the building are designed on the same. Manual calculations were compared with the STAAD Pro results. The structure, which was constructed as G+9, was required to be vertically expanded to G+13. Thereby redesigning and retrofitting measures were taken to modify the structure to withstand increased load.

Concrete structures experience cracks due to faulty design, drying shrinkage, thermal contraction effects, etc. A continuous network of cracks escalates degradation due to increased permeability and exposure of embedded rebars to ambient air. Contemporary sustainability issues of construction sector demand durability of materials and structure for longer service life. Incorporating self-healing mechanism of cracks can be made to flourish at initial stages under certain controlled conditions. The objective of this paper is to explore the laboratory-proven biological techniques to induce self-healing in concrete in terms of ease of preparation, process and cost. The effect on concrete characteristics like compressive and flexural strength, permeability of water, corrosion resistance of the reinforcement bars are studied and presented in this paper.

Profiled deck composite slab is very common to use in construction, and the full-scale laboratory test on profiled deck composite slab is very expensive and time-consuming. This paper describes a finite element analysis of profiled deck composite slab using ANSYS. The main objective is to understand the deflection as well as slip characteristics of composite slab. For this study, simply supported slab is considered with variation of three parameters: the type of profiled deck sheet, concrete depth, and thickness of sheet. It has been observed that concrete depth and type of profiled deck sheet play a major role in load carrying capacity.

Rapidly increasing urbanisation and subsequently ascending shortage of land in the urban areas has pushed the design engineers to switch to the utilisation of the vertical spaces in the form of high-rise buildings and reduce the horizontally vast design popular in the previous era. However, this step not only enhances the criticality of the design processes but also increases our dependency on design codes. Talking specifically about India, the dependency of Indian design community was majorly on international codes due to the non-availability of a design code for tall buildings. It also gave rise to a wide gap in the design community about different provisions. However, recently Bureau of Indian Standards has launched First Tall Building Code of India, IS 16700:2017 “Criteria of Structural Safety of Tall Concrete Buildings.” Despite a good effort of bringing the Indian design community at the same base scale, this code still lacks in a clear depiction of certain aspects. It is also felt that commentary of this code may be provided in a similar fashion as of ASCE 07:2016, ACI 318:2014 to facilitate the adoption of the code. As a first step to it, this study is mainly aimed towards understanding some of the critical structural aspects of the code so as to develop a better understanding in practitioners and design engineers about it. Moreover, some critical clauses are also highlighted through a comparison of the same with various existing international standards.

The surge in the occurrence of intentional and accidental blast events around the world has highlighted the susceptibility of the infrastructure to this type of extreme loading. For new construction, blast-resistant design philosophy or guidelines can be incorporated during the initial stages of conception. However, for the existing structures, retrofitting schemes need to be devised to augment the blast resistance of the structures. The retrofitting schemes particularly employing the use of fiber-reinforced polymers (FRP) as compared to the others are very popular due to their on-field ease of application. This study explores the effectiveness and feasibility of the application of FRPs in this domain. The study further seeks to comprehensively address the realms of the current knowledge state in this field, and moreover to direct further attention of the global research community to address the shortcomings in this field.

The triple friction pendulum (TFP) system is a new generation sliding isolation having four spherical sliding surfaces with three effective pendula. Due to multiple sliding surfaces, TFP system shows highly adaptive behaviour under different hazard level of earthquakes, despite being a passive system. In this research work, a mathematical model and seismic response pertaining to TFP system under maximum considered earthquakes have been described. Series model composed of existing nonlinear element is described along with its hysteretic force–displacement behaviour. Effective period and effective damping in combination with desirable displacement capacity of TFP bearing designs are considered. Due to the presence of multiple sliding surfaces, sliding displacement is distributed over the multiple surfaces and seismic energy is dissipated. It is also found that, at low input, TFP bearing stiffens. It gets soften with the increase in input. And, it gets stiffen against higher levels of input. Thus, it shows highly adaptive behaviour under different hazard levels of earthquake.

Finite element simulation of the impact analysis of circular and rectangular water tanks subjected to projectile impact has been carried out using ANSYS Explicit Dynamics 15.0. Analyses were performed by considering both with water and without water for circular and rectangular water tanks. The different impact velocities considered in the present study were 50, 100, 200 and 400 kmph. The water tank is considered to be fixed at slab base. Due to the limitation on the maximum number of nodes in the academic version of ANSYS, finite element modelling of water tank has been carried out on a water tank of reduced capacity of 4400 L. The reduced tank has a height of 1.40 m and diameter as 2 m. The size of meshing is taken as 100 mm, and thickness of the base slab considered is 150 mm. Salient results such as total deformation, principal stresses, equivalent stresses, normal stresses and the directional deformation for both circular and rectangular tanks with water and without water cases for the different velocities were obtained. The comparison of the various results for the different cases was detailed. It is observed that with the use of finite element simulation, one can come to an optimized shape of the tank with least amount of internal stresses developed within.

Pervious concrete is a sure sort of concrete with a high porosity utilized for concrete flatwork applications that will permit the water from precipitation and different sources to go straightforwardly through, along these lines diminishes the overflow from a site and permitting groundwater to revive. The concrete glue at that point coats the totals and enables water to go through the concrete piece. With interconnected void content, we can achieve high porosity. Water-to-cementitious material ratio is 0.40–0.50. Designs were made at different water–cement ratios, and these ratios show the different exposure conditions. In this paper, specific gravity of cement, coarse aggregate and fine aggregate were selected as 3.15, 2.68, 2.65 respectively. Cement used in this project was OPC-43. Coarse aggregate were used at different proportions. The present examination tended to the strength and seepage parts of pervious concrete mix and furthermore the impact of CS as FA. A point-by-point contemplate is required to know the impacts of total degree with different kinds of total. In this undertaking, the mechanical properties of pervious concrete have been used to plan road pavements. The properties of PCC blend to be examined are compressive strenth and flexural strength. An optimum percentage has been determined which shows the concrete is permeable and having good compressive and flexural strength. In this research paper, the mechanical properties of pervious concrete have been used to design road pavements. Main focus of the paper is to determine and improve compressive strength, and flexural strength.

The standard target of this research paper is to break down and outline a multistoried building [G+10] (three-dimensional frame) utilizing AutoCAD and STAAD Pro and to observe the influence it has on the building execution when the grade of cement is changed. AutoCAD has an extremely intuitive UI which enables the clients to design their structure in 2D utilizing exceptionally fundamental charges. At that point out, the AutoCAD record was transferred to STAAD Pro. The scope includes stack estimations physically and breaking down the entire structure by STAAD Pro. The outline techniques utilized as a part of STAAD-Pro examination are limit state design adjusting to Indian Standard Code of Practice. STAAD Pro highlights a best in class UI, representation devices, capable of investigation and outline motors with cutting edge limited component and dynamic examination capacities. From previous literature works it has been observed that for investigation and configuration to perception and result check, STAAD Pro provides proper solution. At that point as indicated by the predefined criteria allotted, it analyses the structure and plans the individual elements with reinforcement details for RCC frame. We proceeded with our work with some more multistoried 2D and 3D outlines under different load cases. Our last research work was the best possible examination and plan of a G+10, 3-D RCC frame under different load cases. It clearly portrays that the adjustments in the concrete and steel amount with the difference in concrete grade ranging from M25 to M60 concrete.

The main aim of the study was to find out how the existing building can be further extended to meet the functional requirement, without demolition of the original building by using retrofitting techniques. The existing structure is a residential G+4-storied building of RCC framed structure . In order to find out the structural system of the building, the design was carried out for G+4-storied building with STAAD Pro software, since original design details of the structure were not readily available. Then, redesigning was done for G+7-storied structures to find out the revised details of column and beams mainly. There was a need for retrofitting of the structure to strengthen the structure for the safety of the structure. The scope of work consists of designing/redesigning of the structure to find out the revised section of the structural elements. To determine the requirement of retrofitting of the structure, revised design of structure with increased load was carried out for three additional vertical extensions of building and was find out the overall requirement of retrofitting, to avoid disasters .

Pile work contributes as a major component of material consumption in civil engineering domain of a refinery, a petrochemical complex construction or an industrial project in general. Most of the current project sites often require use of piles as foundation due to the poor soil conditions and poorer bearing capacities. The current practice in Indian refinery sector is to design the piles and their arrangements according to the provisions of Indian standards. Indian standard adopts the “working stress design approach” which has been in extensive use till date for the design of gamut of foundations, viz. isolated footings, raft foundations, pile foundations, etc. with a global factor of safety. However, internationally a new design concept, limit state design approach as per Eurocode has gained popularity in recent times. Eurocodes are a well-established benchmark for many countries all over the world. Eurocodes lay emphasis on soil–ground interactions, besides just superstructure and explain the design of soil–ground interactions in such a way that limit states may be reached for pile groups as well. Recent designs of pile and pile group arrangement in Indian parlance using the European standards have shown encouraging signs of savings in terms of reduced number of piles required. This paper presents a comparative study of the number of piles required for a pipe rack structure in a refinery complex using Indian standard and Eurocodes. This paper further gives the quantitative idea of possible savings in materials that can be attained using the advanced code and attempts to explore the reason for the same. The possible savings in carbon footprint during refinery construction due to this material saving have also been attempted.

In our research, we worked over the effects of using RHA and sugarcane baggage ash as a partial weight of cement replacement in cement mortar roof tile production. This work is based on an experimental study of roof tiles produced with ordinary Portland cement (OPC) and 10, 15, 20% (OPC) replaced by RHA and with sugarcane baggage ash separately. Rice husk and sugarcane baggage were brought form Bulandshahr and Allahabad and ash was produced by open-air burning the rice husk and sugarcane baggage away from the city. The tests which were performed evaluate the performance of this material were compressive strength, wet transverse strength, and water absorption. The samples were produced according IS CODE 1237-2012. Overall results show that RHA and sugarcane baggage ash have a reasonable potential to be used for the production of cement mortar roof tiles. Utilization of these waste materials will benefit society economically as well as environmentally.

This paper brings to light the use of waste plastic in the construction of roads. The waste plastic generation is increasing significantly on a daily basis. Through this review, we intend to find the efficient and feasible ways to reutilize the waste particles in hard-plastic waste as a bitumen modifier primarily for flexible pavements like bitumen and bituminous concrete roads. The use of waste plastic in recycled form in the pavement asphalt can serve as a valuable outlet for such type of waste materials. By using the concrete having modified bitumen mix along with processed waste plastic of about 5–10% by wt. of bitumen leads to a substantial improvement in the fatigue life, strength and other properties desirable in bituminous concrete. Consequently, it improves the service life and pavement performance with a marginal but significant saving in usage of bitumen in road construction. This process is certainly environment-friendly. Using waste plastics in the construction of pavements helps to consume large quantity of plastics which are hazardous waste. Thus, these processes also have high social and ecological relevance and contribute toward sustainable development. There are two processes to mix the plastic in surface layer of the road wet process and dry process. We are using wet mix process for the bitumen mix design by adding plastic waste and compare the results with the standard bitumen mix. We have chosen Marshall mix design for the calculation of grading and optimum bitumen and plastic content in mix. We are mainly focusing on surface layer of wearing course of about 50 mm thick, i.e., surface layer of road. This could be helpful in managing waste plastic while improving road quality and making them economical too.

This paper focuses on an experimental investigational work of raw (fresh) properties and hardened properties (HP) of self-compacting concrete (SCC) containing recycled coarse aggregate (RCA) and silpozz. In SCC mix, natural coarse aggregate (NCA) has been replaced with RCA by 0, 10 and 20%, also the cement has been replaced with silpozz by 10% of its weight. To know the raw properties of SCC, the slump cone, T₅₀₀, J-ring, V-funnel, L-box and U-box tests are carried out, whereas for HP of SCC, the compressive strength (CS) test, flexural strength (FS) test and split tensile strength (STS) tests are carried out. The M30 grade concrete is designed for this investigational work. The fine aggregate (FA) quantity increases to 35% and coarse aggregate (CA) quantity decreases to 35% with water–cement ratio (w/c) 0.43 and superplasticizer (SP) of 0.35 and 0.5%. An attempt has been taken to identify the potential use of RCA with silpozz and necessity of the raw and hardened properties for the design SCC mix.

Earthquake causes massive destruction to all the infrastructure facilities such as buildings, power lines and airport terminals. The extent of damage depends on the associated energy, magnitude and epicenter distance. The effects of earthquakes are responsible for ground shakings which in turn shakes the structure, liquefaction in which subsoil losses its strength. During earthquakes, the ground experiences high accelerations resulting in back and forth moment of the structure. Unless the structures are designed and constructed to withstand seismic forces, the failure cannot be avoided. Building can be made seismically sound with proper structure design, detailing and construction practice. The performance depends on how the real-life conditions like material properties and ground motion data are accurately simulated. Flat slab is a reinforced slab built monolithically with the supporting column without provision of beams. Configuration of a building is very much important for seismic performance of buildings. The important aspects that affect seismic configuration of a building are overall geometry and structural system. This parameter varies in their behaviour in flat slab and conventional slab. In the present study, G + 6 multi-storey RC-frame structure is considered for the analysis. Typical storey height of building is 3.2 m. To study the dynamic behaviour of RC frame structure with conventional slab system and flat slab system, two models have been prepared in ETABS software and response spectrum analysis has been performed.

During the earthquake, the structures are subjected to earthquake forces and the adjacent structure may collide with each other due to different dynamic characteristics. When building vibrates out of phase and separated gap between buildings are not sufficient to accommodate their relative motions, this can cause severe damage to the structures, and it is known as seismic pounding. Many times maintaining sufficient pounding gap between adjacent buildings becomes difficult due to site constraints. The present work evaluates the minimum separation gap required between high-rise buildings. Two high-rise building of 10 storeys and 15 storeys are modelled and analysed for dynamic time history analysis for the EI Centro ground motions, and minimum pounding gap between buildings has been discussed.

The quality of an asphalt mix is one of the most important and significant factors that affects the performance of both hot and cold mix flexible pavements. High-quality mixes are often cost-effective as these mixes require less maintenance and increase the service life of the pavements. It is also cost-efficient to replace the semi-experimental flexible pavement design methods with fast and powerful software that includes finite element analysis. Recently utilizing fibres to enhance the bituminous mixtures’ performance under moving loads has been considerably developed. Previous studies show that using natural and synthetic fibres in the bituminous mixtures enhances the mechanical properties of such mixtures, but none exists for the cold mix asphalt. A series of wheel-tracking tests was conducted to evaluate the permanent deformation performance of flexible pavements under different stress levels and temperatures. Very good agreement has been obtained between the developed finite element model and experimental results for determining rutting depth. Results show that the flexible pavements based on cold mix asphalt can be improved under moving loads using natural and synthetic fibres.

FRP-based structural strengthening has emerged as a popular approach for rehabilitating the distressed and underperforming concrete structures. Design of FRP-based structural strengthening systems involves an interesting interplay of uncertainties between those inherent in the existing structure being strengthened and those arising from the lack of complete knowledge and time testimony of using FRP composites for structural strengthening. The safety formats prescribed by most strengthening design standards remain largely cloned from that used for the design of new concrete structures, with a set of safety factors which are significantly higher (up to 2–3 times) than the conventional norm in design of concrete structures. These higher safety factors are proposed to account for the additional uncertainties associated with FRP composites. However, FRP composites in general, and their use as externally bonded reinforcement for strengthening in particular, involve substantially peculiar characteristics compared to reinforced concrete (RC). Therefore, the design processes for strength (for new RC structures) and additional strength (for strengthening existing RC structures) have conflicting design requirements and objectives. Under these conditions, a blind extension of the conventional safety format to design for FRP-based structural strengthening will not only fall short in providing the required safety margins, but could also instigate negative implications and undesirable side effects under some design scenarios. This paper highlights important sources of conservatism in strengthening design arising from the design treatments of uncertainties and mechanics of FRP, and their implications on the course and quality of strengthening design solutions and that on their resultant safety contents are discussed.

In recent years, the need for sustainable yet economically viable structural materials has drawn special attention of the construction industry apart from the traditional parameters concerning safety and serviceability. One such material of interest gaining popularity in the twentieth century is the basalt fibre, due to its cost-effectiveness and desirable engineering properties, especially with respect to fire resistance. Basalt fibres are formed from basalt rocks and hence fulfil the concept of sustainable design and green building. Basalt can commonly be used as a structural reinforcing material in the form of bars, sheets, chopped fibres, etc. Talking specifically about chopped basalt fibres, the dosage of fibre plays an important role in its case. This paper mainly highlights the existing studies on the optimum dosage of chopped basalt fibres with respect to strength aspect and points out several critical comments on the relation of fibre content with workability through experimental testing.