Browsing by Author "Barai, Sudhir Kumar"

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8 - Fly ash-incorporated recycled coarse aggregate-based concrete
(Elsiever, 2021) Barai, Sudhir Kumar
This chapter focuses on the feasible use of partial cement substituted by fly ash in 100% recycled coarse aggregate-based concrete (feasible use of fly ash in recycled aggregate concrete [FARAC]). The effect of particle packing method of mix proportioning is explored. Performance of such sustainable concrete is assessed for both strength and durability. At material level, this chapter examines fresh and hardened concrete properties. Microstructural analysis provides some insights for macrolevel behavior. Finer spherical fly ash particles and triple mixing method improve workability of recycled aggregate concrete (RAC). The negative effects of RAC on compressive strength (CS) is only significant at early ages (7 days), which reduces with adequate curing in RAC with 30% fly ash. Split tensile strength and the ratio of split tensile to CS decreases, which implies reduction of the rate of development of tensile strength at higher CS in RAC. Presence of fly ash in RAC causes densification of pores, thereby increasing the resistance to chemical attack. Fly ash used as cement substitution also proves to be beneficial as far as the creep and shrinkage of concrete is concerned. Adverse effects at material level can be accounted for with necessary design considerations for safe application of FARAC as structural components (beam, column, and slabs).
Abonyi, Janos 43 Alchanatis, Victor 159 Avineri, Erel 221 Ballerini, Lucia 149
(Springer, 2009) Barai, Sudhir Kumar
Contains a collection of papers that were presented at the 12th On-line World Conference on Soft Computing in Industrial Applications, held in October 2007
Advances in Sustainable Construction Materials and Geotechnical Engineering
(Springer, 2020) Barai, Sudhir Kumar
Air Quality Forecaster: Moving Window Based Neuro Models
(Springer, 2009) Barai, Sudhir Kumar
The present paper aims to demonstrate neural network based air quality forecaster, which can work with limited number of data sets and are robust enough to handle air pollutant concentrations data and meteorological data. Performance of neural network models is reported using novel approach of moving window concept for data modelling. The performance of model is checked with reference to other research work and found to be encouraging.
Air Quality Prediction: An Opportunistic Neuro-Ensemble Approach
(Sage, 2003) Barai, Sudhir Kumar
The present article discusses the development of neural-network-based air quality prediction models which can work with a limited number of data sets and are robust enough to handle data with noise. Five different variations of neural network models (partial recurrent network (PRNM), sequential network construction (SNCM), self-organizing feature maps (SOFM), moving window (MWM), and integrated normalized autoregressive moving average-self-organized feature maps models (NARMA-SOFM)), were implemented in a WINDOWS environment using MATLAB software. Developed models were run to simulate and forecast the daily average data for three parameters: RPM (respirable particulate matter), SO2 (sulphur dioxide), and NO2 (nitrogen dioxide) for the Ashram Chowk location in New Delhi, India. The implemented models were found to predict air quality patterns with modest accuracy. To improve the models’ performance, an innovative approach using an opportunistic ensemble of the first four developed neural network models (OEM) was proposed for predicting the same short-term data. The ensemble approach indeed demonstrated an improvement on earlier models. However, the NARMA-SOFM model performed the best.
Application of Novel Radial Thresholding Method for the Segmentation of Different Phases from X-Ray Microtomographic Images of Concrete
(Springer, 2020-11-14) Barai, Sudhir Kumar
Concrete is a composite material, which can be segmented into three major phases, namely voids, aggregates and mortar. This paper presents the digital image processing techniques based on grey value thresholding and a novel radial thresholding approach to segregate the three phases of concrete. In this context, the 8-bit images of concrete specimen obtained from X-ray microtomography (XRT) scanning of cylindrical specimen are operated. The non-local means denoising filter is used to remove the unwanted noise from the original images and enhance their clarity without losing any details. There is a clear distinction in the grey values of air voids from that of aggregates and mortar. The threshold grey value of air voids is determined by observing the variation in grey value profile near the edges of the air voids, and using this threshold grey value, air voids are segmented assuredly. However, the segmentation of phases using this thresholding technique doesn’t suffice to isolate the aggregates from mortar because of the overlap of their grey values. Hence, a radial thresholding method is proposed for the detection and determination of the phases, which works similar to our eyes. The grey value vs radius graph exhibits sudden jumps, which represent the change in contrast, that is, phase. The change in phases is evaluated by using a simple function, ∥GV(n)−GV(n−1)|−L|>0 which is considered the radial variation for every degree rotation. The estimated air voids and aggregates content are 0.91 and 49.19%, respectively. The error in the detection of aggregates content is only 0.6%.
Artificial Neural Networks And Artificial Intelligence Paradigms In Damage Assessment Of Steel Railway Bridges
(2013) Barai, Sudhir Kumar
Structural analysu, structural deslgn and structural apprasal are three mportaut constituents of structural engmeemg Though, the former two topics have been researched well and practiced mth greater emphssls, the latter has largely been Ignored by the profession at large Inspite of recorded evidence of major structural fadures world-mde, m senous attempts have been made towards systematic mvestlgation on the topic of struc-tural assessment, at par with the areas of dysu and design Only recently the importance and complexity of damage assessment~ s bemg bcussed openly and profeselonally
Assessment of the influence of Nano-Silica on the behavior of mortar using factorial design of experiments
(Elsiever, 2014-10) Barai, Sudhir Kumar
The influence of water/cement ratio and addition of Nano-Silica as partial replacement of cement on the compressive strength and water absorption of mortar mixes is a topic of current research. For this purpose, 32 factorial design is selected with water/cement ratio and Nano-Silica (%) as factors. The levels of water/cement ratio are kept at 0.40, 0.45 and 0.50. The levels of other factor Nano-Silica (%) is kept at 0%, 1.5%, and 3%. Compressive strength at 3, 7, and 28 days and water absorption at 28 days are selected as responses. The Analysis of Variance (ANOVA) of test results for aforementioned responses considering the factors depict that the selected factors are significantly affecting the test results. However, the analysis indicates that interactions of factors are not statistically significant. In addition to the above, the study illustrates that consistency and setting time of cement paste is considerably affected by the incorporation of Nano-Silica.
Automation in Site Management: A Qualitative Approach
(IAARC, 2007) Barai, Sudhir Kumar
This paper will address a new approach to construction management: Qualitative Construction Site Assessment System (QCSAS). QCSAS is essentially a site management software package. The objective of this system is three fold. Firstly, it aims to provide a holistic view of construction site to the project manager. It tries to achieve this by tracking essential factors like construction progress, construction quality, safety on site and resource requirement. Secondly, it assesses the condition of all factors on site in qualitative terms by using fuzzy logic. Thirdly, the system intends to achieve smooth information flow between various participants of site, i.e., the site supervisors, procurement officer, quality inspector, safety engineer, planning engineer and project manager with minimal effort and time wastage.
Axial load prediction of circular hybrid double-skin tubular columns using interpretable gradient boosting machine learning models
(Springer, 2026-01) Singh, Shamsher Bahadur; Barai, Sudhir Kumar
This study assesses the predictive performance of three gradient-boosting Machine Learning (ML) models, Gradient Boosting Machine (GBM), eXtreme Gradient Boosting (XGBoost), and Light Gradient Boosting Machine (LightGBM), in axial load prediction of circular FRP-concrete-steel double-skin tubular columns (hybrid DSTCs). Data from 275 specimens were compiled from 22 publications in the literature to train and test ML models. Input variables consist of the height of column (), outer diameter of the FRP tube (), outer thickness of the FRP tube (), diameter of the inner steel tube (), thickness of the inner steel tube (), tensile strength of the outer FRP tube (), yield strength of the inner steel tube (), and compressive strength of concrete (), with the ultimate axial load () serving as the output variable. Performance of all three gradient ML models was evaluated using statistical measures including coefficient of determination (R2), root mean square error (RMSE), mean absolute percentage error (MAPE), and mean absolute error (MAE) for training and testing datasets. Results indicate that the XGBoost model performed better than the other two gradient Models (GBM and LightGBM) with R2 values of 0.97 on the training data and 0.95 on the testing data. Further analysis of the XGBoost model assessed the relative importance of input features on the output feature.
Background on Techniques for Sustainable Use of Recycled Aggregate and Application of Particle Packing Method
(Springer, 2024-02) Pradhan, Subhasis; Barai, Sudhir Kumar
Concrete is an attested building material because of its versatility and cost-effectiveness. Thus, it is the second most consumed material in the world after water (ISO/TC 71, 2005; Weil et al., 2006; Knoeri et al., 2013). Its production and use is escalated by about 12 times since the Second World War and in present scenario the yearly per capita concrete production is about 4.8 tonnes (Monkman and MacDonald, 2017).
Beam-column joints made of self-compacting concrete containing recycled coarse aggregates and nano-silica
(Inderscience, 2020-03) Barai, Sudhir Kumar
This research focuses on the analysis of beam-column joints prepared using self-compacting concrete (SCC) incorporated with nano-silica (NS) and recycled coarse aggregates (RCA). For this purpose, beam-column joint behaviour of normal concrete, SCC incorporating RCA and NS was examined under static loading condition. Analysis of the experimental results indicates that the performance of the joints made with RCA is comparable with that of normal concrete in terms of cracking and ultimate load-carrying capacity. This study also depicts that compressive strength (CS) of SCC made with 100% RCA is somewhat higher than that of SCC made with normal aggregates. Moreover, enhancement in CS can be obtained with the introduction of NS in SCC containing 100% RCA.
Behaviour of recycled aggregate concrete under drop weight impact load
(Elsiever, 2011-01) Barai, Sudhir Kumar
This paper presents the experimental results of recycled aggregate concrete (RAC) beams prepared with different amount of recycled coarse aggregate (RCA) subjected to low velocity impact. The recycled coarse aggregates are obtained from a demolished RCC culvert. Four concrete mixes with 0%, 25%, 50% and 100% RCA respectively are prepared. With each mix three beam specimens of size 1.15 × 0.1 × 0.15 m are prepared and tested under drop weight impact load. The behavior of the RAC beams are studied in terms of acceleration, strains and support reaction histories under impact load in addition to the physical and mechanical characteristics of RCA and RAC. It is observed that 25% RCA does not influence the strength of concrete. In addition, it is found that for a given impact energy (the energy imparted by the hammer per blow) the reactions and strains of RAC with 50% and 100% RCA are significantly lower and higher respectively than those of normal concrete and RAC with 25% RCA.
Behaviour of reinforced concrete beams
(Springer, 2025-10) Barai, Sudhir Kumar
In the preceding chapters, we have discussed the properties of concrete, specifically focussing on the material behaviour of SCM and recycled coarse aggregates. The primary challenge in incorporating this sustainable recycled material is to fulfil the performance requirements of structural elements subjected to flexural, shear, and compression. The behaviour of reinforced concrete RAC beams under bending and shear is discussed in this chapter. Load carrying capacity, failure pattern and effects of material parameters are examined for fly ash incorporated 100% RAC beams. We evaluate the suitability of current code provisions for natural aggregate concrete to be used in RAC with fly ash beams. Furthermore, reliability of structural elements is evaluated, considering the variabilities associated with these recycled materials. Necessary modifications are suggested to achieve the same level of safety as conventional concrete.
Behaviour of reinforced concrete slabs under punching shear
(Springer, 2025-10) Barai, Sudhir Kumar
Flat slab supported by an interior column is a complicated problem due to the most likely phenomenon of punching shear failure. This chapter discusses the punching shear behaviour of recycled aggregate concrete with coarse RCA. In the context of using SCMs in concrete, we address the following question: How does low-volume fly ash as a cement substitute alter the punching shear of RAC flat slabs? Another aspect while using any recycled material is maintaining the level of structural safety as that of the already existing material. The punching shear resistance design equation, available for the standard reinforced concrete slabs, may not yield a safe design for RAC slabs due to greater uncertainties. The reliability of standard punching shear models is assessed and modified to ensure equivalent safety for RAC and NAC flat slabs. It is crucial to conduct this reliability analysis in order to confidently establish fly ash and 100% coarse RCA as alternative concrete constituents in practice.
Biocement treatment for upcycling construction and demolition wastes as concrete aggregates
(Springer, 2022-06) Barai, Sudhir Kumar
Reutilisation of the construction and demolition (C&D) wastes as aggregate in concrete is a vital step towards sustainability as it prevents depletion of natural resources as well as alleviates wastes. However, the attached mortar on the aggregate surface renders certain shortcomings like excessive water absorption, high porosity, and weak interfaces. Recycled aggregates can be treated to improve these shortcomings. However, the minimisation of the drawbacks involves huge energy, materials, and cost. Moreover, the efficacy of such adopted method is sometime questionable, and which needs further research. This study demonstrates bio-treatment of recycled coarse aggregate (RCA) as a means of upcycling and compares it with conventional cement slurry treatment. A novel spraying technique has been applied that significantly economises biocement treatment. The experimental results show that biocement treatment reduced the water absorption by 70%. The treatment has filled the pores of RCA and has prevented water absorption. In contrast, cement slurry coating treatment shows increase in water absorption of RCA by 19%. The compressive strength of concrete with 100% biocement treated RCA surpasses that of concrete with natural coarse aggregates. The genesis of this dramatic improvement in case of biocement has been established through micro-scale studies including scanning electron microscopy and energy-dispersive X-ray spectroscopy. The cost analysis demonstrates that RCA upcycled with biocement treatment is more economical than natural aggregates or cement treated ones. Findings of the present study led to the conclusion that 100% replacement of natural coarse aggregates can be achieved by upcycling C&D wastes as coarse aggregate through bio-treatment.
Characteristics of Mortars Containing Colloidal Nano-Silica
(Research India Publications, 2014) Barai, Sudhir Kumar
The aim of the present study is to investigate the influence partial replacement of cement with colloidal Nano-silica on the compressive strength of cement mortar. This paper reports the results of compressive strength test undertaken on 70.6 mm cube samples of the cement mortar prepared with three different water cement ratio along with varying percentage of Nano-silica. The compressive strength is determined after 7 and 28 days of curing, and water absorption after 28 days. The results of this experimental study reveal that the incorporation of Nano-silica enhances the early strength of cement mortar along with improvement of strength at 28 days. Moreover, the study reveals that water absorption of cement mortar reduces with addition of Nano-Silica due to reduction of minute pores present in cement mortar.
Characteristics of sustainable concrete incorporating recycled coarse aggregates and colloidal nano-silica
(Techno Press, 2015-09) Barai, Sudhir Kumar
The present study addresses about the development of sustainable concrete utilizing recycled coarse aggregates manufactured form waste concrete and colloidal Nano-Silica. Experimental investigations are carried out to determine compressive and tensile strength of concrete mixes designed with recycled coarse aggregates and different percentages of Nano-Silica. Moreover, water absorption, density and volume voids of concrete mixes are also examined to ascertain the influence of Nano-Silica on behavior of recycled aggregate concrete. The outcomes of the research depict that properties of concrete mixes are significantly affected with the introduction of recycled coarse aggregates in place of the natural coarse aggregates.However, the study reveals that the depletion of behavior of recycled aggregate concrete could be restored with the incorporation of little amount (3%) of Nano-Silica.
Characterization of Materials
(Springer, 2024-02) Pradhan, Subhasis; Barai, Sudhir Kumar
Concrete is a composite material and a heterogeneous mixture of cement, coarse aggregate, fine aggregate, water, and chemical admixture. The behaviour and performance of concrete in the fresh as well as hardened stages largely depend on the physical, mechanical, and chemical properties of its constituents. Hence, it is important to determine the characteristics of the raw materials prior to the designing of concrete mix for their intended application. This book aims to compare the performance of concrete, prepared using two different types of coarse aggregates (natural coarse aggregate (NCA) and recycled coarse aggregate (RCA)). The subsequent sections exclusively discuss the differences in physical and mechanical properties between NCA and RCA.
Chloride diffusion study in different types of concrete using finite element method (FEM)
(Techno Press, 2014-03) Barai, Sudhir Kumar
Corrosion in RCC structures is one of the most important factors that affects the structure‟s durability and subsequently causes reduction of serviceability. The most severe cause of this corrosion is chloride attack. Hence, to prevent this to happen proper understanding of the chloride penetration into concrete structures is necessary. In this study, first the mechanism of this chloride attack is understood and various parameters affecting the process are identified. Then an FEM modelling is carried out for the chloride diffusion process. The effects of fly ash and slag on the diffusion coefficient and chloride penetration depth in various mixes of concretes are also analyzed through integrating Virtual RCPT Lab and FEM.