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.

&nbsp;

&nbsp;

VIT University

Civil

The aim of this study is to investigate the effects of sodium silicate solution with varying concentrations on aluminosilicate- based geopolymer mortars. The total binder content of 600 kg m-3 is maintained in all the mix design. The sodium silicate solution with a modular ratio (SiO2/Na2O) of 2 had been used. The molarity of the sodium silicate solution varies in the region of 1 &lt; M &lt; 2.5. It can be observed from the test results that there is a significant effect of silicate solution on aluminosilicate based geopolymer under ambient curing. The mix FG2.5 with a high concentration (2.5 M) of Na2SiO3 solution had achieved 110 mm mortar flow with sticky mortar because of the high viscosity nature of solution which shows compressive strength of 46 MPa at 28-day. The geopolymer mortar mixes containing 2 M, 1.75 M and 1.5 M showed low viscosity mortar with a slight decrease in strength as compared to 2.5 M. The SEM and EDX analysis revealed that, with a high concentration of the solution, the geopolymer matrix was densely formed. However, the increase in the concentration of the solution resulted in, low micro cracks on the surface of the specimens at a magnification of 2 μm. The Si/Al ratio of all the mixes laid in between 3.37 to 4.1. Therefore, the concentration of the solution in the region 1.25 &lt; M &lt; 2 has shown the better results with consideration of mortar flow, compressive strength, and microstructural observation. © 2019 IOP Publishing Ltd.

World University root node

School of Civil Engineering

Chennai Campus

Materials Research Express

Performance of Na2SiO3 solution fly ash based geopolymer mortar under ambient curing

Concrete infilled steel tubular section (CFST) is a composite column used for modern construction. CFST column system is the most successful system, and the confinement of concrete by steel tubular sections enhances in core’s strength. In recent scenario, stainless steel has been popular and widely used in many modern structural applications owing to their anti-corrosion resistance, durability, good in appearance and easy in maintenance. Stainless steel is quite expensive. To reduce the cost significantly stainless steel tube filled with concrete that is, concrete filled steel tubular (CFSST) is used and it is referred as composite material system. This composite material system has a wide application in column made up of concrete, to provide a better performance in terms of strength, stiffness, ductility and seismic resistance. Compare to all other composite material system. This paper discuss about the different types of stainless steel tubular sections, shapes used for stub column under axial loading, strength enhancement and the different modes of failures both experimentally &amp; analytically of stub column. © BEIESP.

International Journal of Engineering and Advanced Technology

Confinement of concrete by stainless steel tubular sections – A review

Geopolymer Concrete (GPC) is the most promising and novel concreting technology which primarily focuses on the eco-friendly aspects. In this work, the mechanical properties of fly-ash based GPC which includes compressive strength, split tensile strength and non-destructive testing methods like UPV and rebound hammer tests results will be examined and analyzed based on the different mix parameters for 8 mixes. The main varying parameters of the mix are alkaline solution ratio and concentration and binder proportions. Based on the optimum mix from 8 normal GPC mixes, one mix will be studied under the granite powder replacement. The granite powder is utilized for the partial replacement of binder for the 5%, 10%, 15%, and 20% of the binder volume. The concrete cube specimens are casted according to Indian standards and the 7th and 28th days strength are used for the analysis. © Blue Eyes Intelligence Engineering & Sciences Publication.

International Journal of Innovative Technology and Exploring Engineering

Study on mechanical properties of geopolymer concrete

This paper presents the experimental investigation on concrete which attempts to utilize the industrial wastes to the possible extent and internal curing compound to promote self-compacting self-curing light weight concrete. Cinder, Ground Granulated Blast Furnace Slag (GGBFS), Super plasticizers and Polyethylene Glycol (PEG-400) are used in the concrete mix and the tests are conducted to confirm its suitability as self-compacting self-curing concrete. The test results of air cured concrete are well comparable with that of water cured conventional concrete. Cinder, an industrial waste product is used as a light weight aggregate by partial and full replacement for coarse aggregate to satisfy the property for structural concrete and optimum use of water in the construction contribute to the sustainable development. © IAEME Publication.

International Journal of Civil Engineering and Technology

Self-compacting self-curing low density concrete using cinder aggregate and PEG

Advanced technological aspects of concrete have been recently focused on developing novel admixtures, which are exhibit high strength and high performance. The extraordinary mechanical properties of Multiwalled carbon nanotubes (MWCNTs) propose that they are ideal admixtures for high strength and high performance concrete. However the major confront connected with the dosage of Multiwalled carbon nanotubes (MWCNTs) in concrete. The purpose of this exertion is to investigate the dosage effect of MWCNTs, on the strength properties (compressive, split tensile and flexural strengths) of concrete at temperature of 26 ± 5°C and 59 ± 5% relative humidity. Tests were performed on specimens from different proportions of MWCNTs viz; 0.05%, 0.10%, 0.15%, 0.2%, 0.25% and 0.3% of by weight of cement. The compressive strength, split tensile strength and flexural strength of the hardened samples were determined after 7, 14, 28, 56, 90, 180, 360 days of water curing. Results reveal that the 0.25% of MWCNTs is the optimum dosage for achieving maximum compressive strength, split tensile strength and flexural strength. © BEIESP.

International Journal of Recent Technology and Engineering

The optimum dosage of the multiwalled carbon nanotubes for improving the mechanical properties of concrete

The developments of using Multiwalled carbon nanotubes (MWCNTs) in sustainable structural concrete is increasing due to its extraordinary strength and stiffness properties, but the durability studies in this area are very less. In this exertion, the effect of incorporation of different dosages (0 %-0.40 %) of MWCNTs has been made to study the strength and durability characteristics of sustainable structural concrete. Concrete mixes were evaluated for compressive strength, Chloride permeability and Ultrasonic pulse velocity at various ages of 7, 14, 28, 56 and 90 days. The results obtained from these tests are unveiling, the incorporation of 0.25 % MWCNTs by weight of cement material performed more desirable. © BEIESP.

Strength and durability characteristics of sustainable structural concrete influenced by multiwalled carbon nanotubes: An experimental exertion

In recent year significant research has been carried out for seismic protection techniques for various types of building. Turbo generator building which is the important part of power plant structures falls under category of special industrial building and are irregular in plan with complex frames, presents many problem during analysis of earthquake forces. The turbo-generator building is considered to be vulnerable to earthquake forces needs to be protected. In this research, nonlinear time history analysis of turbo generator building has carried out with fixed base, base isolation and dampers using SAP 2000 v14 software. Time history analysis has been done to determine the response of turbo generator building with fixed base and to find out seismic response control efficiency with seismic protection techniques. © BEIESP.

Structural performance of non-linear analysis of turbo generator building using seismic protection techniques

Increase in the dosage of superplasticizer can have a significant effect on workability and strength properties of Geopolymer concrete in ambient curing. This paper evaluates the influence of different superplasticizer doage on workability and strength properties of GGBS based Geopolymer concrete. In this study, Geopolymer concrete was made up of 100% GGBS, sodium silicate to sodium hydroxide ratio of 2.5, Alkaline to Binder ratio of 0.5, superplasticizer (2% to 6%) and the concentration of sodium hydroxide of 12M. Significant increase in workability and slight decrease in strength was observed with increase in superplasticizer under ambient curing. The combination of 6% superplasticizer and 12M NaOH concentration of GGBS based Geopolymer concrete was advisable for precast construction under ambient curing. © 2019 Elsevier Ltd. All rights reserved.

VIT Unitversity

Materials Today: Proceedings

Role of Superplasticizer on GGBS based Geopolymer Concrete under ambient curing

The geopolymer concrete is a developing unconventional binder with low eco-friendly effect and possible to increase sustainability of concrete construction. The cement has been substituted by fly ash and alccofine with varying different percentages. The testing methods carried out in this paper are compression strength, split tensile strength and flexural strength. In this paper, 10M sodium hydroxide was used. The result shows that GPC (geopolymer concrete) produced with fly ash and alccofine enhances the properties. Concrete cubes, cylinder and beam samples were casted and tested to obtain mechanical and durability properties of various mixes. © BEIESP.

Flexural behavior of fly ash based geopolymer concrete using alccofine

Purpose: Construction projects in India continue to suffer excessive delays. This paper aims to investigate the delay causes in India by project sector (transport, power, buildings and water) and carry out a comparative study of delay causes in design build (DB) projects with that of design bid build (DBB) projects along with mitigation measures. Design/methodology/approach: A questionnaire survey was conducted among major clients, contractors and consultants in India. Importance Index was used for ranking of the delay causes. Projects were categorized based on the type, and causes of delay in each project type were identified. Projects were also categorized based on type of contract, and delay causes in DB and DBB projects were compared. Statistical analysis of responses by Cronbach’s alpha, one-way analysis of variance, Kruskal–Wallis tests was carried out with Statistical Package for Social Sciences. Semi-structured in-depth interviews were conducted with senior industry professionals to develop exhaustive mitigation measures. Findings: The research findings indicate finance-related causes as the most critical causes of delay in Indian projects. Delay in settlement of claims, contractor’s financial difficulties, delay in payment for extra work/variations by owner, late payment from contractor to subcontractor or suppliers, variation orders/changes of scope by owner during construction and changes in design by owner were the highly ranked delay causes. The research found no significant difference in the delay causes in DB and DBB projects. Originality/value: This is the first study wherein delay causes for various project types within a single country are identified. In addition, the study has identified and compared the delay causes in DB projects and DBB projects. Mitigation measures developed in this study will help professionals and project managers not just in India but other developing countries as well to alleviate delay causes and in improvement of project timelines. © 2019, Emerald Publishing Limited.