The effect of damage produced by delayed ettringite formation, DEF, on the fracture properties of concrete are evaluated experimentally using the cohesive crack model framework. Five concretes containing cements with different composition were studied. All concretes were submitted to Fu´s…
The effect of damage produced by delayed ettringite formation, DEF, on the fracture properties of concrete are evaluated experimentally using the cohesive crack model framework. Five concretes containing cements with different composition were studied. All concretes were submitted to Fu´s accelerated curing method to trigger DEF, stored under water at 23 + 1 ºC during 180 days and then tested. Both stable three-point bend test, according to RILEM recommendation, and splitting test were performed. From these tests the specific fracture energy, splitting tensile strength and bilinear softening curve were obtained. Additionally, longitudinal resonance frequency and length change were recorded during the curing time. The results show that the fracture mechanics parameters proved to be an adequate tool to measure concrete deterioration due to “DEF”. As the DEF in the matrix increased, the evolution of the softening curve shown that the maximum cohesive tensile stress decreases whereas the critical opening crack increases. As consequence of these changes the fracture energy remains constant and the concrete becomes more “ductile”.