Effects of sulfate attack and dry-wet circulation on creep of fly-ash slag concrete

Creep and sulfate erosion resistance of concrete are very important in terms of performance of concrete. It is of great interests to combine these two effects together to make a comprehensive investigation of the long-term performance of concrete. However, the research of the concrete creep under both dry-wet circulation and sulfate attack condition has rarely been reported. This paper firstly conducted experiments on the creep of concrete subjected to dry-wet cycle and sulfate attack. The test factors considered in this study include load stress level, sulfate solution concentration, immersion ways including long-term immersion (LM) and dry-wet cycle (DW). Then a creep model of concrete under sulfate corrosion was proposed considering concrete damage by mechanics theory, the prediction from the modified creep model is in good agreement with the test data. Taking into account the dry-wet cycles effects in the BP-KX model of concrete creep, the paper presented a model to predict the creep of concrete under dry-wet circulation and sulfate attack based on the creep model of concrete under sulfate corrosion. Finally, the calculated results from this new model were compared with the test data and the characteristics, shortage and applicability of this new model were also discussed.