Influence of specimen thickness on cracking behavior in restrained shrinkage ring test

Abstract

The standard test method using circular ring is adopted to assess the potential cracking of restrained shrinkage concrete by ASTM and AASHTO, respectively. The difference of them is the ring specimen thickness, which are 37.5 mm and 75 mm. To investigate the mechanism of ring tests with two concrete thicknesses, a numerical approach is proposed to simulate stress development and crack initiation in restrained concrete ring subject to circumferential drying.Afictitious temperature field is applied on concrete ring to simulate the mechanical effect of shrinkage of concrete. Cracking age and position of those concrete ring specimens are obtained from numerical analyses which agree reasonably well with experimental results. It is found that thin and thick ring specimens exhibit different cracking behavior, and the specimen thickness influences the cracking age, position and propagated direction.