Study on the stress relaxation properties of self-compacting concrete under restrained autogenous shrinkage

Abstract

The development of internal stress and stress relaxation induced by restrained autogenous shrinkage of self-compacting concrete (SCC) with different water to binder ratios and different amount of cementitious materials was investigated. Test results at more than 100 days showed that the free autogenous deformation expands within 1 day and then shrinks rapidly from 3 days to 7 days, after that, the autogenous shrinkage grows slowly and steadily. The induced stress in the restrained autogenous shrinkage also had the similar law; the stress relaxation of restrained autogenous shrinkage mainly developed in the early ages within 7 days, and then growth of the stress relaxation was almost stagnant. Stress relaxation rate of self-compacting concrete increased with the increase of cementitious content, and it increased significantly with the increase of water to binder ratio.