Damage behaviors of self-compacting concrete and prediction model under coupling effect of salt freeze-thaw and flexural load

• The damage behaviors of self-compacting concrete under coupling effect of salt freeze-thaw and flexural load were studied.
• Higher stress levels always caused earlier and more occurrences of brittle fracture.
• A prediction model of damage degree of self-compacting concrete was proposed.

In this paper, the workability, mechanical properties and damage behaviors of self-compacting concrete (SCC) under coupling effect of salt freeze-thaw and flexural load were experimentally investigated. The results showed that the workability of fresh SCC and mechanical properties could be influenced by fly ash, blast furnace slag and silica fume added in the mixture. Salt freeze-thaw had small influences on the surface erosion and relative dynamic elastic modulus of the SCC used in this study. Under coupling effect of salt freeze-thaw and flexural load, different levels of flexural load were applied on the SCC specimens. The results showed that with increasing salt freeze-thaw cycles, the weight loss increased and the relative dynamic elastic modulus declined. The coupling effect had a slight influence on the surface erosion, while it had a significant influence on the occurrence of brittle fracture. Higher stress levels always caused earlier and more occurrences of brittle fracture. A prediction model of the damage degree of SCC was proposed by incorporating the test results achieved in the paper. The comparison results showed that the prediction values had good consistencies with the experimental values. The model is expected to be used to predict the damage degree of SCC under coupling effect of salt freeze-thaw and flexural load.