ORCID Profile
0000-0002-3836-9298
Current Organisation
University of Engineering and Technology
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Publisher: Elsevier BV
Date: 05-2020
Publisher: Elsevier BV
Date: 03-2019
Publisher: MDPI AG
Date: 12-08-2022
DOI: 10.3390/SU14169989
Abstract: This study investigates the influences of three types of locally available low-cost Fiber Reinforced Polymers (FRP) wraps and two concrete mix designs on the axial behavior of FRP confined concrete. The experimental program comprised four unconfined (control), four glass FRP Matt Strand (GFRP-MS) confined concrete, four glass FRP Rowing (GFRP-R) confined concrete and four carbon FRP (CFRP) confined concrete specimens with a diameter of 150 mm and a height of 300 mm tested under axial compression. The specimens were prepared using two normal strength concrete mix designs, i.e., Mix-A and Mix-B. The experimental results exhibited that an increase in the confined concrete strength per unit cost ratio of a single layer of GFRP-MS was about two times of a single layer of CFRP wrap, whereas the increase in confined concrete strength per unit cost ratio of single layer of GFRP-R was about four times of a single layer of CFRP wrap. GFRP-MS and GFRP-R wraps can exhibit similar confined strengths as CFRP wrap with six and twelve times lower costs, respectively, than CFRP wrap. Mix-B concrete specimens exhibited higher confined concrete strengths but lower confined concrete strain than Mix-A concrete specimens. A database of 140 FRP confined concrete specimens was developed based on a set of specific criteria to develop a design-oriented model to predict the FRP confined concrete strength. The predicted confined concrete strengths matched well with the experimental confined concrete strengths. The two layers of GFRP-R exhibited similar confined concrete strength as CFRP wrap. In addition, GFRP-R exhibited high cement strength index (CSI) and low embodied CO2 index (CI).
Publisher: SAGE Publications
Date: 04-12-2018
Abstract: Numerous research studies experimentally investigated the axial compressive behavior of fiber-reinforced polymer tube confined concrete cylinders in the past two decades. However, only a limited number of research studies developed stress–strain models to predict the strength and strain enhancement ratio of fiber-reinforced polymer tube confined concrete cylinders under axial compression. The available strength and strain enhancement ratio models of fiber-reinforced polymer tube confined concrete cylinders are a function of actual confinement ratio only. This study develops strength and strain enhancement ratio models for circular fiber-reinforced polymer tube confined concrete under axial compression based on artificial neural network analyses using Purelin and Tansig transfer functions. The developed strength and strain enhancement ratio models are functions of actual confinement ratio, orientation of fibers, height to diameter ratio, and axial strain in unconfined concrete at peak axial stress. The formulation and performance evaluation of the developed strength and strain enhancement ratio models are carried out using experimental investigation results of 238 circular fiber-reinforced polymer tube confined concrete under concentric axial compression compiled from a database of 599 fiber-reinforced polymer tube confined concrete specimens. The predictions of the developed strength and strain enhancement ratio models match well with the experimental investigation results of the compiled database. The developed strength and strain enhancement ratio models exhibit smaller statistical errors than the available models in the research studies for predicting the strength and strain enhancement ratios of circular fiber-reinforced polymer tube confined concrete under axial compression.
Publisher: ASTM International
Date: 02-07-2019
DOI: 10.1520/JTE20180660
Publisher: American Society of Civil Engineers (ASCE)
Date: 06-2017
Publisher: Wiley
Date: 07-2022
Abstract: Millions of tons of waste glass are produced globally. The use of waste glass in concrete is an environmentally friendly solution, contributing to sustainable construction practices. This study investigates the potential of using recycled waste glass powder ( RWGP ) in foamed concrete nonload bearing wall panels as acoustic barriers. This study investigates the axial and flexural behavior of wall panels constructed with foamed concrete incorporating RWGP . A total of ten 900 mm long and 700 mm wide wall panels of foamed concrete with RWGP reinforced with 7.6 mm diameter steel mesh were cast and tested. Five wall panels were 75 mm thick and reinforced with one layer of steel mesh and the other five wall panels were 120 mm thick and reinforced with two layers of steel mesh. The experimental results exhibited that 120 mm thick wall panels sustained significantly higher peak axial and flexural loads, bending moments, axial deformations at peak axial load and midspan deflections at peak flexural load than 75 mm thick wall panels. The available design codes of masonry structures underestimated the peak axial loads and the bending moments of wall panels by about 9% and 17%, respectively.
Publisher: Elsevier BV
Date: 2018
Publisher: Elsevier BV
Date: 09-2016
Publisher: Elsevier BV
Date: 03-2021
Publisher: MDPI AG
Date: 29-04-2023
DOI: 10.3390/BUILDINGS13051191
Abstract: This study investigates the shear behavior of slender steel-reinforced geopolymer concrete (GPC) beams with the shear span to effective depth ratio (a/d) of 4.5 and 5.0. To investigate the effect of shear reinforcement, two ordinary Portland cement concrete (OPC) beams and two GPC beams without shear reinforcement, and two OPC beams and two GPC beams reinforced with shear stirrups were cast. All beams were 150 mm wide and 225 mm deep with lengths of 1770 mm (a/d=4.5) and 1950 mm (a/d=5). The beams were tested under a three-point bending test. The experimental results showed that OPC and GPC beams without and with shear reinforcements exhibited similar crack propagation and failure mechanism. The midspan deflections of GPC beams were greater than OPC beams. The normalized shear resistance of OPC and GPC beams with a/d ratio 4.5 was greater than 4% and 30%, respectively, than beams with a/d ratio 5. OPC beams showed a greater decrease in shear resistance with an increasing a/d ratio compared to GPC beams. The shear resistances computed using empirical relationships available in various OPC design codes including AC1-318-14, AC1-318-19, fib-10 and JSCE-07 underestimated the experimental shear resistance of both OPC and GPC beams. In addition, the environmental assessment of OPC and GPC beams exhibited that GPC beams emit about 34% lower embodied CO2 emissions than OPC beams.
No related grants have been discovered for Dr. Qasim Shaukat Khan.