Civil Engineering

Utilization of waste tires may be considered as one of the solution to the problems faced by the local authorities in disposing them. Reclaimed rubber (RR) is being used in concrete for replacing conventional aggregates. This research work is focused on the strength prediction of reclaimed rubber concrete using a Genetic Algorithm (GA) for M40 grade of concrete and comparing it with experimental results. 1000 sets were taken and 100 iterations were run during training of GA models. A base study has been carried out in this research work partially replacing cement with three types of fillers such as Plaster of Paris (POP), Fly Ash (FA) and Silica Fume (SF). A total of 243 cubes were cast and tested for compression using a Universal Testing Machine. It was found that SF produced maximum strength in concrete and was used in the main study with reclaimed rubber. Tests were conducted on 81 cube samples with a combination of optimum SF percent and various proportions of RR replacing coars...

Concrete is a common material used in the building industry. It is obtained by mixing cementitious materials, water, fine and coarse aggregates and sometimes admixtures in required proportions. Admixtures are added to concrete to modify its properties so as to make it more suitable for any situation. The aim of this research is to study the strength and durability index of concrete using mineral admixture of C30 grade concrete. The objective of this study is to investigate the effect of Mineral Admixture (Silica Fume) on the strength of concrete produced from cement (OPC). From previous studies it is observed that Silica Fume increases the strength of concrete, so this study has been conducted to know the effect of Silica Fume as an admixture on the compressive strength of concrete produced from cement (OPC). It also reflects the impact of adding admixture on the compressive strength and durability characteristics of concrete. Fifteen cubes were cast in mould with dimension 150mm x ...

Green concrete is a type of concrete that uses waste materials as one of its ingredients. Hazardous wastes like fly ash and silica fume can be used to partially replace cement in concrete, which varies in physical and chemical properties. On the other hand, the increase in automobiles in urban and rural areas has led to an increase in the number of waste tires, which promotes environmental pollution due to disposal issues throughout the world. This study aims to use waste materials which can partially replace cement and conventional aggregates in the concrete mix. Fly Ash (FA), Silica Fume (SF), and Plaster of Paris (PP) replaced cement, whereas Reclaimed Rubber (RR) partially replaced coarse aggregates by weight. This work is focused on experimentation and simulation of M 40 grade mix using the above four materials. 306 cubes were cast by replacing cement with FA, SF, and PP in 3% increments up to 24%. Similarly, coarse aggregates were replaced with RR using the same proportion. Co...

The research has shown that use of tire rubber as coarse aggregate in Reutilization of waste tire material can help reduce the environmental pollution, generated each year in Oman's landfills, where tire waste is often improperly or illegally disposed of. The number of vehicles over the decade has increased considerably, and the need to identify feasible solutions to minimize tire waste is needed. The aim of this project is to identify the optimal use of waste tire rubber as coarse aggregate by partial replacement of 10%, 15%, and 20% with micro silica in the concrete. The objective of this research study is to determine and evaluate the fresh and hardened properties of the concrete. The micro silica replaced the cement by 10%, 20% in the first experiment to determine if micro silica improved the strength in the concrete. Additionally, in the second experiment, the tire rubber was treated in NaOH solution to determine the bonding improvement between the rubber and cement, while using the same replacement ratio. The mix design was developed for C35 strength for both experiments. Using 150X150X150mm cube moulds a total of 28 cubes were casted and cured for 28 days under normal conditions. The mix proportion used is 1: 1.73: 2.2 with water cement ratio of 0.47. The objective of this research is to determine the fresh and hardened properties of concrete under the influence of rubber and mineral admixtures. The results of the experiments showed a reduction in compressive strength as tire rubber content increased when compared to control mix. However, the tire rubber treated in NaOH solution yielded slightly better compressive strength results overall. Furthermore, as the tire rubber content increased a reduction in the workability and weight of the concrete was observed and recorded. The results revealed that the optimal replacement ratio is 20% silica fume + 10% tire rubber, yielding the highest compressive strength among all specimens tested irrespective of the rubber tire. However, the strength did not exceed the control mix. Therefore, when considering both the economic and environmental perspectives, there is an opportunity to utilize waste tire rubber in concrete for non-structural and non-load bearing applications.

The replacement of conventional aggregates with alternate materials like Reclaimed Rubber (RR) results in reduction of self-weight and compressive strength of concrete. This reduction in self-weight further decreases the dead load which contributes towards contraction in size of concrete members and reinforcement requirements. This diminution in compressive strength is compensated by replacing cement with supplementary materials like Silica Fume, Fly Ash or GGBS. This research focuses on the effects of partial replacement of cement and coarse aggregates with Silica Fume (SF) and Reclaimed Rubber (RR) respectively in the concrete mix. Concrete mix was prepared for M20 grade by replacing cement and coarse aggregates with SF and RR respectively for cube and cylinder samples. A base study has been carried out through compression and split tension tests by partially replacing cement with SF in 3 percent increments up to 24 percent. Maximum compressive strength of 19.6N/mm2, 24.2N/mm2 and...

Concrete is widely used in domestic, commercial, recreational, rural and educational construction. Concrete basics aim to provide a clear, concise explanation of all aspects of making quality concrete from the materials and properties involved through planning, preparation, casting and curing. Concrete is mixture of cement, coarse, fine aggregates and water. The aim of this research is to determine the influence of spent catalyst and seashells in concrete replacing cement and coarse aggregate. The objective of this study is to analyze the behavior of concrete using seashells and spent catalyst and to compare between the normal concrete and concrete mixed with seashells and spent catalyst. Cement was partially replaced in (10%, 15% and 20%) with spent catalyst and Coarse Aggregate was partially replaced in (5%, 10%, and 15%) with seashells. Cubes were cast in mould with dimension (150mm x 150mm x 150mm) using mix design calculation for C30 grade which was done according to ACI method...

The aim of this study is to investigate the effect of polypropylene fibre addition into eco-concrete made with fly ash, an industrial by product, as partial cement replacement material, and coconut shell, an agricultural waste,  as coarse aggregates, on the mechanical properties of the concrete. Two different mixes were developed, one with coconut shell only as coarse aggregates, and the other with the combination of both conventional aggregates and coconut shell as coarse aggregates. The cement content was replaced with class F fly ash at 10% by weight in the concrete mixes. The volume fractions of polypropylene fibres used in this study were 0.25%, 0.5%, 0.75% and 1.0%. The addition of polypropylene fibres slightly reduces the slump and density of coconut shell concrete. As the volume fraction of fibres increases, the compressive strength and modulus of elasticity of coconut shell concrete also increases by up to 0.5% of fibre volume fraction. The split tensile strength and flexur...

The construction industry relies heavily on concrete as a building material. The coarse aggregate makes up a substantial portion of the volume of concrete. However, the continued exploitation of granite rock for coarse aggregate results in an increase in the future generations’ demand for natural resources. In this investigation, coconut shell was used in the place of conventional aggregate to produce coconut shell lightweight concrete. Class F fly ash was used as a partial substitute for cement to reduce the high cement content of lightweight concrete. The impact of steel fiber addition on the compressive strength and flexural features of sustainable concrete was investigated. A 10% weight replacement of class F fly ash was used in the place of cement. Steel fiber was added at 0.25, 0.5, 0.75, and 1.0% of the concrete volume. The results revealed that the addition of steel fibers enhanced the compressive strength by up to 39%. The addition of steel fiber to reinforced coconut shell...

Liveability is an abstract concept with multiple definitions and interpretations. This study builds a tangible metric for liveability using responses from a user survey and uses Machine Learning (ML) to understand the importance of different factors of the metric. The study defines the liveability metric as an individual’s willingness to live in their current location for the foreseeable future. Stratified random samples of the results from an online survey conducted were used for the analysis. The different factors that the residents identified as impacting their willingness to continue living in their neighborhood were defined as the “perception features” and their decision itself was defined as the “liveability feature”. The survey data were then used in an ML classification model, which predicted any user’s liveability feature, given their perception features. ‘Shapley Scores’ were then used to quantify the marginal contribution of the perception features on the liveability metr...

The land use and land cover change dynamics is in par with the increasing growth of urban developments and associated sprawl. The objective of the study is to quantify such land cover changes caused due to the urban expansion along the outer ring road using Remote Sensing and GIS. The land cover maps are created for four segments namely Chikkarayapuram, Nazarathpettai, Meppur, and Perungalathur for the years of 2009, 2012, and 2016, respectively. The land cover maps are analyzed for changes among seven classes, namely agriculture, barren land, residential units, industry, water body, other vegetation, and marshland (swamp). Further, the land cover maps of the four segments are analyzed for changes in terms of spatiotemporal aspects (area-based land cover change), environmental aspects (green cover change), and economical factors. The urban growth of the Chikkarayapuram, Nazarathpettai, Meppur, and Perungalathur segment along the outer ring road corridor in the years 2009, 2012, and ...

The aim of this study is to investigate the effect of adding fly ash, an industrial by-product and coconut shell, an agricultural waste on the mechanical and flexural characteristics of eco-concrete. The study focuses on density, compressive strength, tensile strength and flexural behaviour of the coconut shell eco-concrete. Two different mixes are developed, one with coconut shell and the other with conventional aggregate and coconut shell as coarse aggregate. The cement content is replaced with class F fly ash at 0%, 10%, 20% and 30% by weight. The test result shows that the coconut shell concrete produced with 10% fly ash has recorded higher compressive, tensile strength than other proportions. Fly ash inclusion further reduces the density of coconut shell concrete. The higher deflection of coconut shell concrete before failure shows that it has failed in a ductile manner. The flexural behaviour is comparable with other lightweight concretes. It is suggested that an eco-friendly, cost effective structural lightweight concrete can be produced by using coconut shell and fly ash.

Corrosion is a natural process, which converts a refined metal to a more chemically-stable form, such as its oxide, hydroxide, or sulphide. Corrosion initiation takes place when the chloride concentration at the rebar level reaches a critical value. The critical chloride level to develop active corrosion of the steel reinforcement is not a unique value. The main reason for the ambiguity and uncertainty about this critical chloride level, which is also often referred as threshold chloride concentration, is its dependency on large number of variables. This study is intended to study the corrosion rate of steel reinforcement embedded in Ultra High Strength Concrete (M100), Ultra high strength concrete(M100) with water soluble polymer and Medium Strength Concrete(M30). The result shows that the M100 grade concrete shows lower corrosion rate than normal strength concrete. The M100 concrete with water soluble polymer exhibits very high rate of corrosion rate.

The present study deals with Finite Element Analysis on shear behaviour of Hybrid Fiber Reinforced Concrete (HFRC) beams retrofitted with and without Glass Fiber Reinforced Polymer (GFRP) laminate as a form of inclined strip in the beam shear zone usingthe well known Finite Element Analysis (FEA) softwareANSYS. In this investigation, steel fibre of 1%, polypropylene fibre of 0.30% and glass fibre of 0.03%, polypropylene fibre of 0.30%by volume of concrete was used as hybrid steel-polypropylene and hybrid glass-polypropylene fibre reinforced concrete respectively. Beams were modeled and analyzedinto two series (Series I and Series II) of size 150 mm x 200 mm in cross section and a total length of 2100 mm. Each series consists of three beams such as control beam, hybrid steel-polypropylene and hybrid glass-polypropylene fibre reinforced concrete beam.Beams retrofitted with and without GFRP laminate are considered as Series II and Series I respectively.Series IIbeams was preloaded initially about 75 % of ultimate load of Series I beams. The analytical study parameters include ultimate load carrying capacity, ultimate deflection and its stiffness relations. The analytical result revealed that beams retrofitted with GFRP laminate significantly increased the load carrying capacity. Beams incorporated with hybrid fibre reduce deflection as compared to control beam.