Browsing by Author "C, C."

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An experimental investigation to determine the properties of fly ash based geopolymers as per indian standards
(Springer, 2019) Saha, S.; C, C.
Production of ordinary Portland cement requires huge quantity of natural resources and also releases huge quantity of carbon dioxide into the atmosphere. Research efforts have been continuing to establish geopolymer as an alternative cementitious material for the replacement of ordinary Portland cement. This paper presents the study to find out the properties of fly ash based geopolymer paste and 28 days compressive strength of geopolymer mortar. Standard consistency, setting time of geopolymer paste has been determined using vicat’s apparatus (according to Indian Standards), which is followed for cement paste, varying the concentration of sodium hydroxide solution from 6 to 16 M. Results indicate higher standard consistency, more time required for setting for fly ash based geopolymer than that of cement paste. Compressive strength of the geopolymer paste and mortar 17 specimens increases with the increase of the concentration of sodium hydroxide solution and decrease beyond 14 M. © 2019, Springer Nature Singapore Pte Ltd.
Assessing the life cycle performance of green building projects: a building performance score (BPS) model approach
(Taylor and Francis Ltd., 2023) Thanu, T.; C, C.; Deepak, D.
Construction industry is one of the major sectors contributing to the economic development of any country. Also, it acts as a major source of pollution towards the environment, and the impact of this is very severe. To overcome this, the concept of sustainability in the construction sector has emerged. In this regard, vital importance is given to the concept of sustainability along with various rating tools to measure green building performance. In the Indian context, existing assessment tools provide major importance to environmental impact rather than economic and social impacts. To address this issue, a Building Performance Score (BPS) model is developed based on the triple bottom priorities of sustainability which consists of environmental, economical, and social concepts. This model includes various indicators that play a major role in the sustainability assessment at various stages in life cycle of building. Different weights were ascertained for these indicators by experts and were further evaluated by Analytical Hierarchy Process (AHP) to understand the importance of these indicators. Furthermore, the importance of BPS model is validated considering three certified green buildings. Additional indicators that form the major source of sustainability that are neglected in the existing assessment tools are also considered in the case studies. The BPS model developed is utilized in different case scenarios to evaluate the performance of buildings and the suggested BPS model is validated through the present study. © 2022 Informa UK Limited, trading as Taylor & Francis Group.
Assessment on performance of steel slag and processed granulated blast furnace slag as an alternative for fine aggregateâ€”an assertive review
(Springer Science and Business Media Deutschland GmbH, 2021) Sudarshan, V.J.; Arpitha, D.; Thilak Kumar, Y.T.; C, C.; Puttaswamy, N.
Sand has always been an integral part of construction in our civilization. It has been the most easily available and acceptable source for the same. However, the depletion of river sand availability has started looking at the alternatives including some industrial by-products. One of them is slag obtained from manufacture/refining of metals which would help in the utilization of industrial waste and conservation of natural resources to have a sustainable construction. This paper provides the gist of organized overview involving the evaluation of physical and chemical characteristics, assessment of mechanical and durability properties for the effective utilization of steel slag and processed granulated blast furnace slag (PGBS) that could be modelled from previous researches related to the study. The basic properties of steel slag and PGBS exhibit requisite properties like river sand which is an indication for a possible alternative material to the conventional aggregate. The multiple processing of slag has its influence on strength, durability, and workability of concrete. These recent innovations have made the slag economically viable and environmentally friendly, and also profitable salvaging of processed by-product. Â© Springer Nature Singapore Pte Ltd 2021.
Characterization and performance of processed lateritic fine aggregates in cement mortars and concretes
(Elsevier Ltd, 2019) Yaragal, S.C.; Basavana Gowda, S.N.; C, C.
Availability of river sand is becoming scarce, due to rapid increase in infrastructure projects in India. Acute shortage of river sand, has led to indiscriminate sand mining. Adverse effect of sand mining includes river bank erosion, river bed degradation, loss of biodiversity and deterioration of river water quality and ground water availability. To address the above issues, research efforts are on, to find substitutes for river sand to be used as fine aggregate in mortars and concretes. One among the locally available resources is laterite. Laterite is a product of tropical or sub-tropical weathering, which is an abundant soil material in many parts of India. An attempt has been made to characterize the processing technique to obtain good quality lateritic fine aggregates (lateritic FA). Experiments were designed and conducted to study the performance of lateritic FA as replacement to river sand, in cement mortars and concretes. Processed lateritic FA in replacement levels of 0, 25, 50, 75 and 100 wt% to river sand at all fineness levels (Zone I to Zone IV as per Indian standards) is considered. Microstructure studies were conducted to understand the arrangement of river sand and lateritic FA with cement matrix and their Interfacial Transition Zones (ITZ) using Scanning Electron Microscope (SEM). The workability and compressive strength characteristics of cement mortars and concretes are evaluated. Laterized mortars with Zone III and Zone IV fine aggregates, at all replacement levels, result in the same compressive strengths as those of control mortars. Suitable strength enhancement technique has been attempted to achieve strengths of Zone I and Zone II lateritic fine aggregates based mortars at 100 wt% replacement, to achieve strength at least equal to or more than those of control mortars. Laterized concretes have achieved nearly the same strengths as those of control concretes, at all replacement levels and for all fineness levels (Zone I to Zone IV). © 2018 Elsevier Ltd
Comparison of Afghanistanâ€™s Construction and Engineering Contract with International Contracts of FIDIC RED BOOK (2017) and NEC4â€”ECC
(Springer Science and Business Media Deutschland GmbH, 2023) Ajmal, M.; C, C.
Construction and engineering contracts are the core documents used to set out contractual relations, rights and obligations of parties, payment systems, communication lines, and dispute avoidance/resolution procedures in construction and engineering projects. Thus the importance of these documents is obvious. In this study, the Standard Bidding Document (SBD) for the Procurement of Small Works (PSWs) of the Government of Afghanistan (whichâ€™s the approximate cost is up to AFN 500 million) is chosen. It is to be compared with the Conditions of Contract for Constructionâ€”FIDIC RED BOOKâ€”2nd Edition (2017) and New Engineering Contracts (NEC4) Engineering and Construction Contract (ECC) 4th Edition (2017). This study was conducted using different research papers, theses and books, which were relevant to the research, and by deep study of the above three mentioned types of documents of contracts. After that, the comparison of Afghanistanâ€™s SBD for the PSWs with the FIDIC RED BOOK (2017) and NEC4â€”ECC (2017) in different parts with each other was carried out. After this comparison, the achieved results show that Afghanistanâ€™s SBD for the PSWs has shortcomings, lack of some essential clauses and/or sub-clauses, insufficient information in some clauses which may lead to disputes, errors and/or mistakes in naming of some clauses, lack of flexibility, and unbalanced risk-sharing. Â© 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
Compressive strength prediction of SCC containing fly ash using SVM and PSO-SVM models
(Structural Engineering Research Centre, 2021) Rajeshwari, R.; Mandal, S.; C, C.
Self-Compacting Concrete (SCC), is a highly workable material, compacted by its self weight without observable segregation and bleeding. In this study, Support Vector Machine (SVM) and particle swarm optimization based SVM models are employed to predict the 28 days compressive strength of individual SCC mix. A database of 62 no’s of SCC compressive strength from literature with cement partially replaced by fly ash is used for training the models. The test data consists of two groups, an individual study consisting of 9 datasets and other combination of three studies with 19 datasets tested separately. Similar input parameters from the train data is extended for testing the models prediction accuracy. Statistical parameters such as correlation coefficient, root mean square error and scatter index are used to evaluate the models’ prediction results. The particle swarm optimization based SVM model is capable of selecting appropriate SVM parameters to increase the prediction accuracy. From the results, it is seen that both SVM and particle swarm optimized SVM models have good capability in predicting the SCC compressive strength. © 2021, Structural Engineering Research Centre. All rights reserved.
Constructive scope on implementation of copper slag as replacement for natural fine aggregateâ€”an overview
(Springer Science and Business Media Deutschland GmbH, 2021) Thilak Kumar, Y.T.; Arpitha, D.; Sudarshan, V.J.; C, C.; Puttaswamy, N.
This paper communicates organized work on copper slag drawn from scientific literature which comprises evaluation of physical and chemical characteristics, mechanical and durability properties in the marine environment. Analysis of test data derived from previously available sources reveals that copper slag having similar basic characteristics is an acceptable alternative material to river sand to produce concrete of all grades. The lesser water absorption property of copper slag is very significant peculiarity which attributes to develop high strength in concrete. The behaviour of concrete produced using copper slag to the concrete made corresponding to sand component shows identical behaviour in the fresh and hardened states. As an aggregate, copper slag has an ability to be replaced with fine aggregate, thereby the advance progress in the concrete technology will revolutionize the mixture of different conventional ingredients to uplift the expected properties of concrete to renew its definition. Hence, alternative materials to be used as fine aggregate will reduce the burden on the environment which is being extensively investigated all over the world looking to the significant requirements, quality and properties which have been a global consensus on the materials. Â© Springer Nature Singapore Pte Ltd 2021.
Critical study on performance of building assessment tools with respect to Indian context
(Institute of Physics Publishing helen.craven@iop.org, 2018) Thanu, H.P.; C, C.
Construction sector is one of the largest end users of environmental resources and is one of the largest polluters of manmade and natural environments around the globe. Economic development, climate change due to the greenhouse gas (GHG) emission, energy security and energy access are the primary concerns for India. Sustainable development in energy sector has become a concern for all the people in the world. Sustainability means it satisfies the needs of the people without jeopardizing the prospects of the future generation. To minimize these effects, the concept of Green Building has been introduced in the construction industry. To asses these buildings, there are various building assessment tools which have emerged globally. These assessment tools have been developed and used to assist the planning and design of sustainable buildings. The aim is to develop complete environmental consciousness among construction specialists towards sustainable performance and to achieve the objective of sustainability in the construction sector. In this study, the assessment approaches towards environmental, economic and social aspects are discussed. The comparative study and analysis on these building assessment tools i.e. LEED-India, GRIHA and IGBC have been made. It is found that there may be inconsistence in the assessment tools and criteria. However, lack of fully integrated assessment tools has resulted in the lack of a holistic assessment approach for the building life cycle. Â© Published under licence by IOP Publishing Ltd.
Early cost estimation of highway projects in India using artificial neural network
(Springer, 2019) Mahalakshmi, G.; C, C.
The objective of this paper is to develop a model to estimate the construction cost of a highway at early stage (conceptual phase) of a project. Cost estimation at conceptual phase is a challenge as only limited information is known. As a result, wide cost variance is eminent at the completion of project. A neural network which can aid in cost estimation is developed. Parameters that can be obtained with least effort and highly influencing on cost are chosen. Developed neural network relates overall highway construction cost described in terms of materials, duration, topography, and prevailing soil conditions. Data of 52 projects were obtained from National Highway Authority of India (NHAI). The obtained results demonstrated that a multi perceptron network with backpropagation algorithm is capable of predicting construction cost of highway with reasonable accuracy. © Springer Nature Singapore Pte Ltd. 2019.
Effect of stiffness on performance of diaphragm wall
(Elsevier Ltd, 2015) Yajnheswaran, B.; R, A.P.; C, C.; Rao, S.
Diaphragm walls are generally constructed using stiff concrete of same stiffness throughout. Research has shown that as wall flexibility increases, the stress imposed by the soil redistribute and reduces structural forces on wall. Approximately five fold reduction in maximum bending moment occurred when wall stiffness was reduced from that of a 1m concrete section to that of a Frodinghamn1N sheet pile. Unfortunately this beneficial effect is accompanied by greater wall and soil movements (Potts & Day, 1991). So the diaphragm wall cannot be too flexible also. In this paper static analysis of two different diaphragm wall sections of varying stiffness is carried out using PLAXIS software for the load condition existing at deep draft berth of New Mangalore Port, and the performances of these sections are compared with previous study performed by Yajnheswaran et al. (2015). The diaphragm wall sections used in analysis are modeled as single panel. The length of the panel is taken as 5m. Anchors are provided at +2.5m. Soil layer details are obtained from boreholes at NMPT. Â© 2015 The Authors. Published by Elsevier Ltd.
Enhancement of the properties of fly ash based geopolymer paste by incorporating ground granulated blast furnace slag
(Elsevier Ltd, 2017) Saha, S.; C, C.
Research efforts have been made continuously to establish fly ash based geopolymer as an alternative binder material for the production of fresh concrete because production of Ordinary Portland Cement degrades the environment by huge emissions of carbon-di-oxide and also by consuming lot of natural resources. But most of the study reveals, fly ash based geopolymer paste needs more time to get set when it is cured at ambient temperature. As a result, it is quite impractical to use fly ash based geopolymer paste as an alternative to Ordinary Portland Cement in faster construction. In this study, an effort has been made to enhance the properties of fly ash based geopolymer paste by incorporating ground granulated blast furnace slag at various percentage levels. Microstructure of the geopolymer paste is studied using Scanning Electron Microscopy. Result of this investigation shows that significant improvement on setting time and compressive strength can be obtained by adding ground granulated blast furnace slag in the mixes. © 2017 Elsevier Ltd
Evolutionary Topology Optimization of Structural Concrete Under Various Load Cases
(Springer Science and Business Media Deutschland GmbH, 2021) Resmy, V.R.; C, C.
Topology optimization has wide applications in the field of engineering as it derives the optimum material layout in a given design space with defined loads and boundary conditions. This article presents the topology optimization of structural concrete with different load cases using a bidirectional evolutionary structural optimization method (BESO). BESO method has several advantages over other optimization methods as it removes inefficient elements and adds efficient elements in each iteration. The methodology adopts the compliance minimization with volume constraint by utilizing the capabilities of ABAQUS finite element software. Strut and Tie model (STM) has been identified as an effective method in modeling discontinuity regions in reinforced concrete structures as it can find out the real load transfer mechanism in structures. With the aid of topology optimization, all the uncertainties related to STM can be avoided. Â© 2021, Springer Nature Singapore Pte Ltd.
EXPERIMENTAL INVESTIGATIONS ON THE PROPERTIES OF CONCRETE CONTAINING PRE-SOAKED RECYCLED FINE AGGREGATE
(Associated Cement Companies Ltd., 2022) Saha, S.; C, C.; Ganiger, M.S.; Sajjan, S.
Recycled fine aggregate (RFA) becomes very significant and promising alternative materials for natural fine aggregate (river sand) to be used in the production of concrete. But, most of the past research works indicated higher water absorption capacity of RFA as one of the key factor to affect the properties of fresh concrete. Therefore, an experimental attempt has been made to address the issues related to water absorption capacity of RFA by soaking it in water for 24 hours prior to use as alternative fine aggregate for the production of the fresh concrete. Mechanical properties of concrete such as compressive strength, splitting tensile strength, and flexural strength, and durability properties such as resistance against acidic and alkaline environment, chloride permeability test for ordinary Portland cement (OPC) and Portland pozzolana cement (PPC) based concrete mixes made with soaked recycled fine aggregates (SRFA) are determined, and analysed. For OPC, and PPC based concrete, respectively 4.32, and 20.75 % in compressive strength at 28 days; 2.69, and 27.24 % increase in flexural strength; 6.38, and 40 % increase in splitting tensile strength at 28 days were observed for the concrete mixes with SRFA compared to the mixes with RFA. Experimental results indicated notable improvement of the mechanical, and durability properties of concrete mixes when recycled fine aggregates were soaked in water prior to use. © 2022, Associated Cement Companies Ltd.. All rights reserved.
Influence of copper slag properties on behaviour of cement mortars and concrete
(Springer Science and Business Media Deutschland GmbH, 2021) Arpitha, D.; C, C.
The promotion of green infrastructure as an alternative to traditional concrete, known as grey infrastructure, is not as benign as many people think. In this concern, many alternative materials have been kept in place as a solution for the problems faced by the construction industry. The knowledge of understanding the basic property of a material is significant as the characteristics cannot be directly assumed that it can be compared to FA while mixing concrete. In this work, Copper Slag (CS) is used as a partial replacement for Fine Aggregate (FA), and a major focus is to understand the behaviour of the material based on its particle size, texture shape and surface characteristics as it decides the quality of concrete. Also, the importance of optimizing water/cement ratio (w/c) and dosage of Superplasticizer (SP) is a major consideration in this work which has a great impact on workability and strength parameter as it affects durability performance of concrete. Marsh cone test to decide optimum SP was carried out for PCE-based SP and Portland Pozzolana Cement (PPC). Optimal w/c ratio was decided based on the trials carried out using flow test for mortars, and mortar cubes were prepared and tested for 3, 7 and 28Â days compressive test. In order to check the behaviour of CS in concrete, cubes were prepared and subjected to compressive strength for 7, 28 and 90Â days based on the ideal waterâ€“cement ratio (w/c) and SP obtained from various trials conducted to achieve required workability and strength. Test results revealed that CS mortars and concrete exhibited higher strength than the control mix. The chemical reaction between the cement matrixes, incorporation of CS and SP for optimized w/c and dosage of SP not only enhanced the strength but also provided the required workability though CS has less water absorption capacity. Â© Springer Nature Singapore Pte Ltd 2021.
Influence of Superplasticizers on Blended Cement and Their Effect on Flow Characteristics by Incorporating PGBS as Partial Replacement for Fine Aggregates
(Springer Science and Business Media Deutschland GmbH, 2021) Arpitha, D.; Sudarshan, V.J.; Thilak Kumar, Y.T.; C, C.
Currently the upsurge practice of the mineral admixtures as an alternative for cement to cut down the carbonic gas emission, to reduce the cement cost, and to progress some technical recitals is truly the indispensable novelty advanced in construction industry. Mortars with different w/c require the use of appropriate and compatible chemical admixtures to achieve desirable consistency. The principal tactic delivered to contest in contradiction to this exertion is to choose the furthermost effective twosome cementâ€“superplasticizer, facilitating to attain a determined water reduction, an enhanced flow, and an adequate rheology. Processed Granulated Blast Furnace Slag (PGBS) incorporated as partial replacement for Fine Aggregates (FA) along with different types of Superplasticizers (SP) for different dosages, which were chemically based on Lignosulfonate (LS), Sulphonated Naphtha Formaldehyde (SNF), and Polycarboxylate Ether (PCE), was used to check the behavior of flow characteristics in this work. The fusion of Portland pozzolana cement (PPC) along with partial replacement of fine aggregates has resulted to understand the better flow interaction between the cementitious materials and under different waterâ€“cement ratio (w/c). Â© 2021, Springer Nature Singapore Pte Ltd.
Influence of the mix parameters on shrinkage properties of environment-friendly mortar
(Taylor and Francis Ltd., 2024) Saha, S.; C, C.
Cracks in concrete structures are generally initiated due to the shrinkage i.e. the volume change characteristics of the concrete structures. In this experimental study, effects of the mix parameters related to alkaline liquid (AL) and recycled fine aggregate (RFA) on the shrinkage behaviour of environment-friendly mortar mixes produced with fly ash (FA)-based geopolymer binder and RFA were investigated and reported. To find out the effects of AL, concentration of liquid sodium hydroxide (LSH) was varied from 6M to 16M, ratio of liquid sodium silicate (LSS) to LSH in AL was varied from 1.0 to 2.5 and AL/FA ratio was considered as 0.4 and 0.6. Different fly ash-based geopolymer mortar mix were produced depending on above-said combinations of mix parameters along with the RFA content (by weight) of 10%, 20%, 30%, 40% and 50% in lieu of natural fine aggregate. Prismatic specimens (25 mm × 25 mm × 285 mm) were cast and cured at ambient air temperature to determine the shrinkage behaviour. Higher RFA content in mix, higher LSS/LSH ratio in AL and higher AL/FA ratio resulted in higher shrinkage value. But, lesser shrinkage value was noticed for those specimens of mortar mix with the consideration of higher concentration of LSH in AL with varying RFA content. ©, Engineers Australia.
Investigation on the potential use of recycled fine aggregate to produce geopolymer mortar mix
(ASTM International, 2019) Saha, S.; C, C.
The utilization of construction and demolition waste (C&DW) partially or fully for various purposes in construction industries is one of the most significant solutions to overcome the scarcity of raw materials and disturbances of the environmental system. On the other hand, geopolymer is being tried to be established as an alternative sustainable binder material for ordinary portland cement. In the present study, with the thought of promoting of sustainability, an attempt has been made to use concrete wastes as recycled fine aggregate (RFA) partially to produce fly ash (FA)-based geopolymer mortar. The workability, water absorption, compressive strength at 3, 7, 28, and 56 days, volume change behavior, and chloride permeability of the produced FA-based geopolymer mortar were determined. The effects of RFA, the ratio of alkali liquid (AL) to FA, and different curing regimes on these properties of mortar mix also discussed. The morphology and microstructures of the samples taken from the mortar mix, which were observed having the highest strength under different curing regimes, were studied using scanning electron microscopy (SEM). The experimental results indicate lower workability, higher water absorption capacity, and higher drying shrinkage of geopolymer mortar mix that has more RFA content in the mix, but the compressive strength of the geopolymer mortar mix started decreasing after a certain percentage of RFA content in the mix. Utilization of that certain percentage of RFA will help us to minimize the consumption of natural fine aggregates and reduce the disturbances generated by unorganized dumping of C&DW. © 2019 by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959.
Investigations on compatibility of cement-superplasticizer interaction and its influence on mortar workability incorporating copper slag as fine aggregate
(Institute of Physics Publishing helen.craven@iop.org, 2018) Arpitha, D.; C, C.; Puttaswamy, N.
Interaction between cement and water is a complex phenomenon to understand. Sometimes achieving the desired results is quite challenging due to the contrast spotted in the characteristics of cement, type and dosage of superplasticizers (S.P) as the behaviour is insignificant. Influence of different types of cement fineness on pastes with different superplasticizers which represents the compatibility between cement with water reducing admixture in order to obtain well-defined saturation dosage and with the partial replacement of fine aggregates (F.A) by copper slag (C.S) to study the mortar behaviour is focused in this work. A methodology based on fundamental properties of cementitious systems using marsh cone and mini-slump cone tests results to identify the suitable and compatible combinations between cement and superplasticizers for the enhancement of flow behaviour of mortar mixes. Â© Published under licence by IOP Publishing Ltd.
Investigations on Flow Characteristics of Mortars Using Partial Replacement of Fine Aggregates with Processed Granulated Blast Furnace Slag
(Springer Science and Business Media Deutschland GmbH, 2021) Sudarshan, V.J.; Arpitha, D.; Thilak Kumar, Y.T.; C, C.; Puttaswamy, N.
Sand has always been an integral part of construction in our civilization. It has been the most easily available and acceptable source for the same. However, the depletion of river sand availability has led us to start looking at the alternatives including some industrial by-products. Processed Granulated Blast Furnace Slag (PGBS) is an alternative slag sand for fine aggregate which is being extensively utilized. Low density and strength issues concerned with Granulated Blast Furnace Slag (GBS) have led to the innovation of PGBS. PGBS is considered as an economically viable and environmentally acceptable alternative material for replacing river sand having tremendous economic impact, conservation of natural resources, and gainful recycling of process by-products. In this study, mini slump cone test is conducted for mortars using 10, 20, 30, and 40% partial replacement of Fine Aggregates (FA) (River sand) with PGBS to study the flow behavior and to identify the suitable combinations of water binder ratio (W/B) (0.4, 0.45, and 0.5) and superplasticizer dosage (0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, and 2.0). Â© 2021, Springer Nature Singapore Pte Ltd.
Mechanical properties of recycled aggregate concrete produced with Portland Pozzolana Cement
(Techno Press technop2@chollian.net, 2016) Saha, S.; C, C.
The quantity of construction and demolition waste has been greatly increasing recently. It causes many problems to the environment. For this reason, demolition waste management becomes inevitable in order to overcome the environmental issues. The present study aims to evaluate the effects of using recycled coarse aggregate, which is generated from construction and demolition waste, on the properties of recycled aggregate concrete. An experimental investigation on the strength characteristics of concrete made with recycled coarse aggregate is presented and discussed in this paper. In this study, Portland Pozzolana Cement (fly ash based) is used instead of ordinary Portland cement. The results of this investigation show the possibility of the use of recycled coarse aggregates in the production of fresh concrete. Use of demolition waste as coarse aggregate will lead to a cleaner environment with a significant reduction of the consumption of natural resources. A comparative study on the strength characteristics of recycled aggregate concrete made with Ordinary Portland Cement and Portland Pozzolana Cement is presented and discussed in this paper. © 2016 Techno-Press, Ltd.