Shear performance of lightweight aggregate concrete with and without chopped fiber reinforced

Abstract

This paper presents a study on the shear performance of two different high-performance chopped fibers (basalt fiber and polyacrylonitrile fiber) employed to reinforce lightweight aggregate concrete. Environmentally friendly supplementary cementitious materials, fly ash and silica fume, are used to substitute a part of cement. Around 21 UDVW specimens are designed to test shear performance. The relationships between the shear strength and the cube compressive strength, splitting strength, flexural strength, and specific strength are established. Although the addition of the fibers does not change the shear failure morphologies, but could change the development direction of the cracks. Moreover, the fibers increase both the peak shear stress and the peak shear strain, and corresponding calculation models are proposed to predict these properties using the coefficient of shear strength enhancement βs. When the fiber content reaches 1% and 1.5%, the normalized shear stress–strain compared wrapped that of plain specimen notably. With an increase in the fiber content, the peak secant shear modulus decreases slightly, whereas the initial tangent shear modulus increases. Moreover, calculation methods are established to compute the peak secant shear modulus and the initial tangent shear modulus. The calculated results of several equations in this study present excellent agreement with the test results.