Flexural behavior of TRC contained chopped fibers subjected to high temperature

Abstract

This paper determined the influence of chopped fibers made of steel, carbon and basalt with different volume contents (i.e., 0.0%, 0.5% and 1.0%) on the flexural behavior of textile reinforced concrete (TRC) after high-temperature treatment. Four-point bending tests were conducted to study the stiffness, deformation, and ultimate load of TRC specimens with different chopped fibers at room temperature and after the required high-temperature time of 0.5 h, 0.75 h and 1.0 h. The results showed that adding chopped fibers to the matrix had a positive effect on the ultimate load; this was especially true for the chopped carbon fibers that exhibited excellent performance. For chopped steel and carbon fibers, the ultimate load improved as the fiber content increased, but this was not the case for chopped basalt fibers after high-temperature treatment. Moreover, scanning electron microscopy and alpha ray spectrometry were conducted, which enabled analysis of the damaged sections of the specimens after the required high-temperature treatments. It was found that different surfaces of chopped fibers obviously changed after high-temperature treatment, which indirectly indicated the mechanical behavior of these specimens was closely related to the characteristics of chopped fibers (i.e., the diameter and surface characteristics) and the corresponding fluidity of the matrix.