Evaluation of the fracture behaviour of concrete prisms reinforced with regular and high-strength steel rebars using acoustic emission technique

Abstract

This study examines the potential of high-strength steel strands of smaller diameter as a substitute for regular steel in normal concrete, aiming to reduce steel consumption and increase sustainability. The fracture behaviour of concrete prisms reinforced with high-strength steel strands is examined using acoustic emission (AE) and digital image correlation (DIC) techniques and compared with those reinforced with thermo-mechanically treated (TMT) bars. The fracture behaviour is examined for the following parameters: the type of reinforcement (TMT and HSS), the number of rebars (1 and 2 rebars), and the percentage of reinforcement (0.22 % of TMT vs. (0.18 % & 0.27%) of HSS, 0.45% of TMT vs. 0.47% of HSS). Test results showed that replacing a similar percentage of TMT rebars with HSS rebars increased load-carrying capacity in serviceability and ultimate load regimes. The enhancement in performance can be attributed to the increased surface area of HSS due to the smaller diameter of bars, which provides better bonding with concrete when compared to TMT rebars. Micro and macro cracking characteristics and damage progression are studied by analysing the peak amplitude from the AE waveform. AE results show that tensile mode cracks dominated initially, and shear mode cracks formed after the specimens reached their first cracking load due to internal reinforcement.