Mixed mode fracture behavior of fiber reinforced concrete; Experimental and numerical analysis adopting cracked Brazilian disc specimen

Fiber reinforced concrete (FRC) is a material of prime importance to enhance fracture resistance of structural elements. It is essential to consider crack initiation and fracture resistance experimentally and select the most convenient and applicable numerical criterion to predict such behavior in FRC. In this study, a total of 40 cylinders and 540 cracked Brazilian discs (CBD) were divided into four groups to evaluate mechanical and fracture properties. The investigated groups include plain concrete (PC), glass fiber reinforced concrete (GRC), polypropylene fiber reinforced concrete (PRC), and hybrid fiber reinforced concrete (HRC) of glass and polypropylene fibers. The CBD was adopted due to its capability to achieve a varied range of mode mixity. Different crack length to disc radius ratios (a/R) and crack inclination angles (beta) were investigated. Fracture loads were determined experimentally then applied to analytical and numerical models to calculate fracture toughness parameters. An elastic two-dimensional finite elements analysis embedded in ABAQUS program was utilized to evaluate fracture behavior regarding mode mixity for the tested range of CBDs. Generalized maximum tangential stress (GMTS) shows supreme fit to the tested data than those of maximum tangential stress (MTS) including all a/R, beta and material types regarding fracture resistance and crack initiation angle. (C) 2023 THE AUTHORS. Published by Elsevier BV on behalf of Faculty of Engineering, Ain Shams University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).