Bond Performance Between Recycled Coarse Aggregate Concrete Reinforced with Polypropylene Fibers and Steel Bars After High-temperature Treatment

Abstract

This paper systematically studies the compressive strength of recycled coarse aggregate concrete with different dosages of polypropylene fibers at high temperatures and the influence of polypropylene fibers on the bond performance between recycled concrete and steel bars at high temperatures. The research results indicated that as the temperature increased, the compressive strength of the concrete decreased. Fibers can improve the compressive strength of concrete, but this effect needs to be controlled within a certain range. As the temperature increased, the bond strength between the concrete and steel bars decreased, while the bond slip increased. The addition of fibers improved the bond performance between the recycled concrete and steel bars, which was mainly reflected by increasing the bond strength and reducing the bond slip. With increasing fiber content, the bond strength between the recycled concrete and steel bars first increased and then decreased. When the fiber content was 0.12 %, the bond strength between the recycled concrete and steel bars was the highest. In addition, a calculation model of the bond strength between steel bars and recycled coarse aggregate concrete with fibers after exposure to high temperatures was established.