Improving the characterization of early age cracking of concrete: engineering issues and scientific answers

Recent studies on the durability of concrete structures have shown the relevance to take into account the evolution of the strength and the damage of concrete at early ages. Research works conducted at GeM Institute since many years have concerned the characterization of early age cracking. In order to achieve these works specific procedures based on the development of original devices have been proposed. This paper focuses on three of these original procedures. It concerns an application of the ring test method to the study of early-age autogenous shrinkage in temperature-controlled conditions, a direct tensile test device for the determination of the deformation capacity of early-age concrete, and a flexural test procedure for the measurement of the crack energy of concrete at very early ages. Test results are presented and analyzed