Civil

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.

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VIT University

School of Civil Engineering

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

Chennai Campus

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.

World University root node

Materials Today: Proceedings

Performance of geopolymer materials concrete filled stainless steel tubular (GCFSST) column subject to axial compression

Stretchable dielectrics exploit their inherent elasticity to enable new types of transducers that convert mechanical energy into electrical energy. Electric power can be altered by simply stretching or shrinking a low cost material, and hence is more desirable now-a-days. The challenge of a material to be sustainable for lifelong is a great task for varying environmental conditions. It could be overcome by making functional coatings over the substrate. The challenge includes choosing resins that stretch along with the substrate uniformly without affecting its dielectric properties. In this article, the effect of different polymer coatings over the dielectric elastomer Lycra is investigated. Elastomeric coatings with the polymer resins silicone, TPU and Epoxy were made by doctor blade method. Dielectric properties measurements and Tensile strength tests pointed out the effectiveness of the coated substrates in stretchable RF devices. SEM micrograph images show the sustainability of the resin coated fabric for varying environmental conditions. © 2020 National Institute of Optoelectronics. All rights reserved.

Journal of Optoelectronics and Advanced Materials

Polymer resin coating over dielectric elastomer for effective stretchable RF devices

This study is about studying the market situation of real estate and automotive industry in and around Chennai during the pandemic season (Covod-19). The study comprises an inter disciplinary approach called as transdisciplinary model where parameters were not considered from single field. The parameters studied are of four varied categories such as psychological, social, economic and logical influence. The basic enquiry log of real estate industry and automatize industry in Chennai is collected and preliminary analysis was made on percentage of conversion from enquiry to sale. Then the enquirers are provided with questionnaire mapped with the influencing parameters, to study their decision taking pattern. The results show that each unit has different influencers, but altogether there was no logical approach hence conforming the panic consumeristic behavior during the time of pandemic. Also, it shows that commercial vehicle section has got a worst heat, and the real estate sale is also in back seat due to unprecedented future. © IAEME Publication Scopus Indexed.

International Journal of Management

Market response of real estate and automotive industry during pandemic-a transdisciplinary approach

We report the growth process and linear and nonlinear optical characterization of high quality improvised semiorganic 2A5NPDP single crystal using the modified SR method for the first time. The major difficulties for the growth of 2A5NPDP single crystal have been resolved with the aid of a temperature lowering method. After optimization of the growth conditions, a transparent 2A5NPDP single crystal was harvested with a size of 85 mm length and 10 mm diameter over a period of 60 days. The growth rate of the modified SR method grown crystal was found to be 10 times higher than that of the conventional slow evaporation solution technique (SEST) grown crystal. The unit cell parameters of the grown crystal were ascertained by the single crystal X-ray diffraction (SXRD) and powder X-ray diffraction (PXRD) techniques. The high crystalline perfection of the crystal was ascertained by using a high-resolution X-ray diffraction (HRXRD) technique. The presence of multifarious functional groups of the 2A5NPDP crystal were confirmed by Fourier transform infrared (FT-IR) and Fourier transform Raman (FT-Raman) spectral analyses. The thermal property was assessed by the thermogravimetric (TG) and differential thermal analysis (DTA). It shows that the grown crystal withstands temperature up to 175 °C. UV-vis-NIR analysis was used to measure the linear optical property while third-order nonlinear optical properties were ascertained using Z-scan and optical limiting (OL) techniques. The optical limiting threshold of conventional method grown crystal is 5.7 mW/cm2, whereas the modified SR method grown crystal is 4.7 mW/cm2. Low value of limiting threshold indicates that the grown crystal has minimum defects. Finally, 800 nm wavelength of 140 fs at 80 MHz repetition rate obtained from a Ti:sapphire oscillator was used for the terahertz (THz) generation between 0.1 and 2.1 THz range. The efficiency of the generated THz signal was measured using another 800 nm wavelength of 40 fs, at 1 kHz repetition rate obtained from a Ti:sapphire amplifier. The generated THz signal is separated out from unconverted 800 nm using Teflon filters, and power is measured using a pyrometer. The maximum conversion efficiency of generated THz signal is on the order of 0.63 × 10-5%. Copyright © 2019 American Chemical Society.

Physics

School of Advanced Sciences

Crystal Growth & Design

Evaluation of Linear and Nonlinear Optical Properties of D−π–A Type 2-Amino-5-Nitropyridinium Dihydrogen Phosphate (2A5NPDP) Single Crystal Grown by the Modified Sankaranarayanan–Ramasamy (SR) Method for Terahertz Generation

Early deterioration of flexible pavements, due to increased traffic volume, environmental conditions, poor maintenance and construction quality, causes difficulties to road users, all around the world. The structural failures such as fatigue and rutting demand the reconstruction of the pavements which further leads to significant construction cost. One potentially sustainable solution to this problem is to adopt perpetual pavement technology. The fatigue and rutting distresses in the pavements can be minimised to some extent by utilising Superpave mixtures with perpetual pavement concept. This paper proposes two polymer-modified Superpave mixtures, one with optimum amount of binder and the other with rich binder content, for the asphalt intermediate and base layers of perpetual pavement, respectively. The optimum mixtures were prepared with two aggregate gradations having nominal maximum aggregate sizes 25 mm and 19 mm for the intermediate layers to enhance the rutting resistance. Rich mixtures were prepared with the same gradations for the asphalt base layer to improve the fatigue resistance. Laboratory tests were conducted on these mixtures to determine moisture susceptibility, rutting resistance, fatigue behaviour and resilient modulus. The fatigue and rutting criteria of perpetual pavement sections were evaluated using KENPAVE software and the critical strains were found to be within the limits. The experimental results and analysis on perpetual pavement sections with proposed mixtures for the intermediate and base layers show that they can be considered as a better alternative for conventional pavements. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.

Road Materials and Pavement Design

Evaluation of Superpave mixtures for perpetual asphalt pavements

This paper deals with the study of durability properties of fly ash and steatite powder based Geopolymer concrete. The activating alkali used was 10 M sodium hydroxide and sodium silicate solution. The ratio of sodium hydroxide and sodium silicate ratio was 1:2.5. The range of replacement levels of flyash with steatite powder was from0 - 50 %. In order to improve the workability of geopolymer concrete, a PC based admixture Glenium B233 has been used for all the mixtures. In addition to that the concrete has been cured at oven at 70oC for about 48 hours. The following durability index properties such as water absorption, sorptivity, rapid chloride penetration test and acid attack test were measured at 28days. The observed results indicated that, increase in steatite powder demonstrates low water absorption and low permeability representing that the material was in a high dense pore structure. Additionally in acid resistance test, there was a decline in the percent losses of compressive strength with particular time period but then again the declination was lower when compared to increase in steatite powder. © 2019 IOP Publishing Ltd. All rights reserved.

Fulltext

IOP Conference Series: Materials Science and Engineering

Durability Performance of Fly Ash and Steatite Powder Based Geopolymer Concrete

The need for incorporation of Reclaimed Asphalt Pavement (RAP) in the Stone Matrix Asphalt (SMA) mixtures is becoming a priority in the pavement industries. The RAP offers several benefits such as the reduction in usage of bitumen, and natural aggregates, and reduction in the landfills, emission into the environment and cost. SMA is known for its success in improving rutting resistance, durability and cracking resistance and to utilize the benefits of both RAP and SMA, it seems a logical purpose to incorporate RAP in the SMA mixtures. However, RAP contains an aged binder, which increases the stiffness of the mixtures and a rejuvenator is added to improve the rheology of the aged binder. In this study, Waste Vegetable Oil (WVO) is used as a rejuvenator in the RAP incorporated SMA mixture. In order to determine the maximum RAP content and optimum WVO dosage, four RAP contents (10, 20, 30, and 40% by weight of the aggregate) and four WVO dosages (0, 3, 6, and 9% by weight of bitumen content) are used to prepare the SMA mixtures. The laboratory tests were conducted to evaluate drain down, volumetric properties, Marshall characteristics, stripping behaviour, Retained Marshall Stability (RMS), and Tensile Strength Ratio (TSR) and they are compared statistically to each other and to the control mixture. The results indicate that RAP incorporated SMA mixtures have a substantial positive effect on the volumetric properties and it enhanced the Marshall Stability (MS), stripping resistance and RMS, however, reduced the TSR value. To the contrary, the addition of the WVO improved the TSR value to a great extent and increased the RAP content. The statistical analysis, Analysis of Variance (ANOVA) results, showed that the RAP content and WVO dosage have a significance on the properties of the SMA, and the main effect plot results concluded that it is possible to incorporate 40% of RAP content with 6% WVO in the SMA mixtures. © 2019 Elsevier Ltd

Construction and Building Materials

Evaluation of rejuvenator’s effectiveness on the reclaimed asphalt pavement incorporated stone matrix asphalt mixtures

The design of the 15 storey R.C building (seismic zone V) is made in accordance with IS 456:2000 using ETABS software. It is already reported that provision of concentric bracing throughout the building are reliable during seismic activity. Hence, this work is aimed to improve the performance of multi storey R.C. building by provision of eccentric steel bracing through analysis. Different types of bracing such as V bracing, Chevron bracing and Diagonal bracing are provided in concentric and eccentric manner. The effect of distribution of steel bracing throughout the height of the building is examined. It is found that the deflection in the building increases with increase in eccentricity. Moreover, V type bracing with 10 percentage eccentricity is found to be most reliable under seismic activity compared to other arrangements.

International Journal of Recent Technology and Engineering Regular Issue

Seismic Performance of Reinforced Concrete Frame with Steel Bracing System

Antibiotics are considered as the significant group of pharmaceuticals which causes a serious hazard to the environment and human health in recent years. Due to the inefficient treatment technologies, conventional wastewater treatment plants (WWTPs) are unable to remove many antibiotics from wastewater. This review encapsulates the current status of antibiotics occurrence in influent and effluent of WWTPs globally. Specifically, β-lactams, fluoroquinolones, macrolides, sulfonamides, tetracyclines classes of antibiotics are found to be high in wastewater. An overview of physicochemical properties, generation classifications of antibiotics, and different advanced oxidation processes (AOPs) available for the removal of emerging pollutants are presented. Besides, the removal efficiency of diverse antibiotics by various AOPs are discussed. The combination such as UV/H2O2, UV/H2O2/Fe2+ and ozonation are reported for maximum removal of antibiotics. However, when compared to simulated wastewater, limitations are persisted for the removal of antibiotics in real wastewater, owing to its difficulty in assessing and observing the compound under mixed nature. AOPs assisted degradation mechanism for ciprofloxacin antibiotic in wastewater is presented and the necessity of research on antibiotic removal is highlighted. © 2019 Elsevier Ltd