Experimental investigations on the asymptotic fracture energy for large mass concrete specimens using wedge splitting test

Abstract

This study presents experimental investigations on the asymptotic fracture energy for mass concrete. Wedge splitting tests were performed on moderate-size and large-size notched concrete specimens using the same mass concrete mixture with maximum aggregate size of 100 mm. Specimens were instrumented with temperature sensors to study the effect of temperature rise at early age. Computation of fracture energies from experimental load-crack mouth opening displacement confirmed the size dependency effect observed in other studies and the asymptotic tendency with size when similar temperature conditions are present. Experimental methods based on Simplified Boundary Effect Method known as SBEM and recently developed Disturbed Fracture Process Zone method or DFPZ were used to assess the asymptotic fracture energy from moderate-size specimens. Results of the two methods were consistent with the experimental results of the large-size specimens and constitute a first validation in literature of these experimental protocols. Finally, comparison of results of large-size specimens with two casting conditions highlighted the important effect of heat of hydration on the asymptotic fracture energy.