Experimental and numerical investigation of flexural behaviour of new DSG reinforced concrete mixes reinforced with GFRP bars

Abstract

This paper presents a new composition of the reinforced concrete material; then, as verification, a study of such proposed composition in the flexural behavior of reinforced concrete beams is done. The work is divided into three stages. Firstly, the use of Damaged Securit Glass (DSG) as a replacement of coarse aggregate within concrete mixes is investigated, which leads to solving an environmental problem. Secondly, an experimental program to examine the flexural behavior of Glass Reinforced Concrete Beam (GRCB) is conducted, in which the casted beams are composed of the new proposed DSG concrete mixes and reinforced by locally-manufactured GFRP bars. The study focuses on simply supported GRCB subjected to four-point bending load. Finally, a numerical verification is carried out by implementing non-linear Finite Element Analysis (FEA) using ANSYS 14.0. The reliability of the FE models is demonstrated by a comparison with the experimental results, which shows good agreement in both load-deflection relationships; as well as failure patterns. Different study results are highlighted; such as: Ultimate load, reinforcement ratio – hence ductility – of GFRP bars, and trend of both compressive strain of concrete and tensile strain of reinforcement bars.The results confirm that the new mixes of Glass Reinforced Concrete (GRC) which have the DSG in its component possess the same ultimate load of similar conventional reinforcement concrete beam (RCB). The most equivalency has occurred when a 20% of weight of the coarse aggregate is replaced by DSG. The results of a flexural study of GFRP beams show that compared with similar RCB, the maximum deflection is decreased by about 47%, the maximum compressive strain of concrete is decreased by about 75%, and the maximum tensile strain of steel is decreased as well by about 92%. Furthermore, when GFRP bars are used in the new GRC mixes, a remarkable increase of the ultimate load is achieved by about 14%. Subsequently, a related increase of the maximum deflection, ultimate tensile strain in the GFRP bars, and ultimate compression strain of concrete are also achieved. Keywords: Damaged Securit Glass (DSG), Glass Fiber-Reinforced Polymer bars (GFRP), Glass Reinforcement Concrete (GRC), RC beam flexural behavior, Cracks, Finite Elements Analysis (FEA)