Study on failure characteristics of basalt fiber reactive powder concrete under uniaxial loading

Abstract

The uniaxial compression experiments of basalt fiber reactive powder concrete (BFRPC) were carried out by acoustic emission (AE) and DIC techniques, focusing on the AE characteristics in the process of BFRPC failure. The cracking modes of internal and surface cracks of BFRPC are judged by clustering analysis of average frequency (AF) and rise angle (RA) based on Gaussian mixture model (GMM) and displacement on both sides of cracks measured by DIC. Research investigates that the peak frequencies of BFRPC are mainly distributed in 5 ∼ 35 kHz, 60 ∼ 100 kHz, 185 ∼ 215 kHz and 230 ∼ 280 kHz. With the increase of stress level, the absolute energy in the peak frequency range increases gradually. The volume content of 0.5% and 1.0% basalt fiber increased the absolute energy in each peak frequency range. Basalt fiber can improve the compressive strength and the strength and density of AE energy of RPC to some extent. The shear failure of BFRPC mainly occurs in the later stage of loading. Basalt fiber can change the failure mode of BFRPC from tensile failure to tensile shear failure. Meanwhile, basalt fiber can effectively increase the stress level during cracking and reduce the damage degree of BFRPC. Judging the AE characteristics and crack types of concrete failure is of great consequence to predict the precursory failure of BFRPC.