Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Civil

Geopolymer concrete is an environmentally - friendly alternative to normal concrete that can significantly reduce the emission of CO2 into the atmosphere for its utilization of by-products from industries. This paper is focused on alumino-silicate source materials like Ground Granulated Blast Furnace Slag (GGBS) used as a binder material. Due to scarcity of river sand manufactured sand (M-sand) acts as fine aggregate. This paper investigates the engineering properties and microstructural studies by using XRD, FTIR and SEM for geopolymer concrete (GPC) mixed with GGBS cured under ambient temperature. The test results revealed that, high early compressive strength is achieved in 28 days by 85 %, XRD results show the formation alumino-silicate and C-S-H gel, and FTIR results show that presence of Si-O-Al bond characteristics. The dense formations of the geopolymer matrix had been observed from the SEM analysis. © 2020 by Advance Scientific Research.

World University root node

School of Civil Engineering

Chennai Campus

Journal of Critical Reviews

Study on engineering and microstructural properties of ambient cured GP concrete produce from GGBS and M-Sand

A simple concrete-based structure model is proposed by developing it from nano to macro structure. In this model, the structure is divided into four levels and each level is represented by a parametric model. The parameters of the four based structures are identified, in terms of elastic modulus (EM) and poisson’s ratio at any time period (t) at Calcium silicate hydrates (CSH), cement paste, mortar and concrete levels. Then, by integrating the proposed model with Bazant – Baweja (B3) model, the compressive strength (CS) and EM of concrete at different curing periods is estimated. Further, it is analyzed and validated by other international models such as B3 model alone, Comite Euro – International Du Beton (CEB) model and Indian standards (IS) method. Few tests were done to investigate the CS of concrete with the inclusion of 25% fly ash (fa) and varying ratios of waste foundry sand (WFS) – 0, 25, 50, 75 and 100%. The results are compared with the obtained values by other models and validated with the experimental results. It is found that the proposed model (PM) i.e., Multiscale modeling (MS) can be used reliably integrated with the other models and builds the interaction between the various matrix to estimate and study the strength parameters of the concrete. MS is a new technique which is based on the mathematical formulation, it doesn’t require any earlier data about the mechanical properties of the concrete except the intrinsic values of the cement-based materials and mix details to evaluate the strength of the concrete. © 2020, Fundatia Serban Solacolu. All rights reserved.

Revista Romana de Materiale/ Romanian Journal of Materials

Mathematical modeling to develop a simple nano to macro structure concrete-based model

The present study is to investigate the basic fresh and hardened concrete properties of flyash based geopolymer concrete admixed with polypropylene fiber and compare to the coventioal geopolymer concrete (without fiber). The fly ash based geopolymer is tested in two phases, one in fresh concrete phase where flow properties are determined after which hardened concrete is tested for its compressive strength. Also, the objective effectively extends to study the strength gain pattern in ambient curing condition. The strength is measured between 3 days to 28 days. The observed results are then converted into a data set, and an Artificial Neural Network Model is created out of the collected results using Levenberg-Marquardt algorithm. The model is trained, validated and tested. Then the predicted value is compared with the actual value. This study proves that polypropylene fiber has enhancing effect on strength properties. Also, ANN model can be effectively created and used with the available data set. © 2020, Alpha Publishers. All rights reserved.

Journal of Green Engineering

Experimental investigation and artificial neural network prediction of fiber admixed flyash based sustainable geopolymer concrete

In today's construction world, aesthetic tall structures play a major role. The design of aesthetic high - rise buildings need to be checked for its safety against extreme load conditions such as earthquake, wind, etc. The provision of composite shear wall is one of the efficient methods to make high rise buildings seismic resistant. In this paper different types of shear walls, namely, concrete shear wall, silica fume concrete shear wall, steel plate shear wall and steel-silica fume concrete composite shear wall are considered for lift wall in 22 and 52 storeyed high-rise buildings. The seismic performance of these buildings is analysed using response spectrum method by ETABS. The factors such as storey displacement, storey drift and storey shear are studied and found that there is a significant reduction when compared to the conventional shear wall. © Published under licence by IOP Publishing Ltd.

Fulltext

IOP Conference Series: Materials Science and Engineering

Seismic Performance of High Rise Buildings with Different Types of Shear Wall

Increase in vehicular traffic and changing environmental; will reduce the service life of concrete surfaces. Repair and maintenance of concrete pavement and floors is a routine practice in India to enhance the serviceability. Abrasion is contributing in lowering the service age of concrete. Many structures such as dams, canals, industrial floors and roads are required to have sufficient abrasion resistance. Abrasion resistance is a property of harden concrete surface to be worn away by abrasive forces. Highly abrasion resistance concrete surfaces are preferred in industry floor and in construction of roads. Aggregates play an important role in strength characteristics of concrete; strength has a decisive influence on abrasion resistance of concrete. This paper presents an overview of some of the research published regarding abrasion testing and effect of concrete properties and ingredients of concrete on abrasion resistance. Studies show that this is promising future for the abrasion resistance of a concrete used in road pavement, industrial floors, dams etc. to assess the serviceability. It was notices from literature that abrasion properties are varying with aggregate type, compressive strength, cement content, W/c ratio, curing and show drastic changes when concrete added with silica fumes, fly ash, fibers and latex. Age of the concrete and type of loading for which concrete surface is exposed play vital role in abrasion. This study culminates to explore abrasion resistance property on assorted mix design, high density concrete and age of concrete. © 2020 Chaoyang University of Technology.

International Journal of Applied Science and Engineering

A comprehensive review on abrasion resistance of concrete

In this study, industrial by-products like fly ash, Ground Granulated Blast Furnace Slag (GGBFS) and silica fume were used to develop the sustainable Self-Compacting Geopolymer Concrete (SCGC) under ambient curing. The combination of source materials is kept constant such as 50% fly ash, 30% Ground Granulated Blast Furnace Slag (GGBFS) and 20% silica fume, respectively. In the series of experiments, sodium silicate (Na2SiO3) solution of 1.75M is kept constant. The Solution/Binder (SB) ratio has been varied such as 0.65, 0.68 and 0.70. Rapid Chloride Permeability Test (RCPT), water absorption and Ultrasonic Pulse Velocity (UPV) of SCGC are measured at 28 days. The test results indicated that, the durability properties were inimically affected with increase in SB ratio and better properties observed with low content SB ratio. This because of increase in Silica (Si) content in the concrete undergoes slow polymerization process at ambient curing. The optimum mix with 0.65 SB ratio is identified with better results and considered for further studies. © Published under licence by IOP Publishing Ltd.

IOP Conference Series: Earth and Environmental Science

Sustainable Self-Compacting Geopolymer Concrete under Ambient Curing-Durability Properties

Reducing the weight of concrete beams is a primary (beyond strength and durability) concern of engineers. Therefore, this research was directed to investigate the impact response of hammerhead pier concrete beams designed with density-based method topology optimization. The finite element topology optimization was conducted using Autodesk fusion 360 considering three different mesh sizes of 7 mm, 10 mm, and adaptive meshing. Three optimized hammerhead beam configurations; HB1, HB2, and HB3, respectively, with volume reductions greater than 50%. In the experimental part of this research, nine beams were cast with identical size and configuration to the optimized beams. Three beams, identical to the optimized beams, were tested under static bending for verification purposes. In comparison, six more beams, as in the preceding three beams but without and with hooked end steel fibers, were tested under repeated impact load. The test results revealed that the highest flexural capacity and impact resistance at crack initiation and failure were recorded for the adaptive mesh beams (HB3 and HB3SF). The failure impact energy and ductility ratio of the beam HB3SF was higher than the beams HB1SF and HB2SF by more than 270%. The results showed that the inclusion of steel fiber duplicated the optimized beam’s impact strength and ductility several times. The failure impact resistance of fibrous beams was higher than their corresponding plain beams by approximately 2300 to4460%, while their impact ductility ratios were higher by 6.0 to 18.1 times. © 2020, Budapest University of Technology and Economics. All rights reserved.

Periodica Polytechnica Civil Engineering

Impact response of hammerhead pier fibrous concrete beams designed with topology optimization

ISBN:978-93-87950-

Structural Design and Drawing

This paper studies the thermal behaviour of ferrosialate geopolymer mortars. This is done by monitoring various factors influencing the strength gain/loss, weight loss, enthalpy changes, physical and chemical transformations in the ferrosialate geopolymer structure using TG/DT analysis. This study proposed a novel predictive equation for estimating this parameter with the help of gene expression programming (GEP). Fly ash is used as a raw feed for sialate geopolymer, and red mud along with fly ash is used for ferrosialate geopolymer. Till 200 °C, oven-cured samples showed maximum strength results. Whereas in later stages, i.e. after exposure to 400 °C, ambient cured samples surpassed the former by 4.14%. Development of broad amorphous hump in the XRD patterns, presence of thicker geopolymer structure in the SEM images for 400 °C samples, an exothermic peak in the DTA curves at 400 °C and increment in the compressive strength up to 400 °C exposure, all pointing to a conclusion that elevated temperature-favoured ferrosialate geopolymer formation till 400 °C. After exposure to 800 °C, maximum strength loss of 68.57% and 30.3% is observed for sialate and ferrosialate samples dehydroxylation, recrystallization, and melting of unreacted particles are the reasons for diminishing the strength at elevated temperatures. An equation using GEP model (r2 = 0.913) having nine genes is proposed that can predict the residual compressive strength of ferrosialate geopolymer mortars. Though this model is for ferrosialate geopolymer, a similar technique can be easily adapted to other types of geopolymers. © 2020, King Fahd University of Petroleum & Minerals.

VIT Unitversity

Arabian Journal for Science and Engineering

Experimental Investigations and Prediction of Thermal Behaviour of Ferrosialate-Based Geopolymer Mortars

Recently, concrete-filled stainless steel tubular (CFSST) columns pay attention to the modern construction field. CFSST column provides significant advantages over the column such as greater in strength resisting capacity, larger energy dissipation and stiffness. In this research work, experimental studies are carried out to examine the behavior of geopolymer concrete mixed with ground granulated blast furnace slag (GGBS) filled stainless steel tubular (GCFSST) column and compared with geopolymer concrete mixed with GGBS filled mild steel tubular (GCFMST) column under axial compressive load. The result reveals that the GCFSST column shows a 7.05% strength enhancement in ultimate load-bearing capacity for the L/D ratio of 5.33 when compared with GCFMST column. Also, experimental values authenticated with the theoretical values calculated based on relevant code specifications show that the ultimate strength obtained is higher than the calculated theoretical values. Also, stainless steel tubes as an outer core material improve the load-bearing capacity of the GCFSST columns. © 2020 Elsevier Ltd. All rights reserved.