Research on dynamic splitting damage characteristics and constitutive model of basalt fiber reinforced concrete based on acoustic emission

Abstract

In order to effectively utilize fiber reinforced concrete in engineering, it is necessary to investigate its mechanical properties and damage characteristics under dynamic tensile loads. This paper studied the effects of loading rate and fiber content on the tensile strength and acoustic emission (AE) characteristics of basalt fiber reinforced concrete (BFRC) in dynamic splitting tests. Brazilian disc splitting tests were carried out on the BFRC specimens with various fiber volume fraction (0%, 0.05%, 0.1%, 0.15%, 0.2%). Then the dynamic splitting AE characteristics were analyzed by means of parameter analysis method. Additionally, the stress–strain curves of BFRC were fitted by the constitutive model modified based on AE rate-process theory. The test results indicate that the tensile strength is enhanced with the increasing loading rate while adding basalt fibers has the same effect. Preferable fiber contents are 0.1% and 0.15%. Then it is found that loading rate and fiber content exert considerable impacts on the AE characteristics. Furthermore, the good fitting results suggest that the mechanics behavior of BFRC under dynamic splitting loads can be well described by the modified constitutive model.