Virtual estimation of the Griffith’s modulus and cohesive strength of ultra-high performance concrete

Abstract

This investigation presents a computational methodology to estimate the unit fracture energy (Griffith’s modulus) and the cohesive strength of ultra-high performance concrete (UHPC). The hydration of plain UHPC mixtures is simulated using the National Institute of Standards and Technology (NIST) Virtual Cement and Concrete Testing Laboratory (VCCTL) hydration simulator. The Young’s modulus of elasticity of the hardened concrete is obtained via finite-element analysis of a sample cube of its micro-structure. Applying the Extended Finite Element modeling capabilities of ABAQUS to previously grooved simple structural elements under gradually-increasing load, the results of computational simulations of the start of crack growth are linked to the corresponding predictions by regressions on experimental observations in classical linear elastic fracture mechanics physical tests. A procedure is developed to estimate both the Griffith’s modulus and the cohesive strength of the UHPC, which are difficult to assess experimentally. As an application, the effect on the horizontal thrust at the abutments of a two-hinged symmetric arch with a crown crack and uniformly loaded is analyzed using the data provided by the pure-bending test on a pre-grooved simply supported beam.