Experimental study on shrinkage of recycled brick powder UHPC
Using recycled brick powder to partially replace cement to prepare concrete is one of the ways to realize the recycling of construction waste.The activated brick powder was used as an auxiliary cementing material to replace part of the cement to prepare UHPC.The law and mechanism of autogenous shrinkage and drying shrinkage of recycled brick powder UHPC under different substitution rates were studied and analyzed.Based on the experiments,a prediction model for the autogenous shrinkage and drying shrinkage of recycled UHPC was established.The results show that replacing cement with recycled brick powder can reduce the autogenous shrinkage of UHPC,and the autogenous shrinkage rate of UHPC decreases with the increase of the replacement rate of brick powder.The drying shrinkage of UHPC can be reduced by replacing cement with recycled brick powder,and the drying shrinkage of UHPC decreases first and then increases with the increase of the replacement rate of brick powder.When the brick powder replacement rate is 30%,the drying shrinkage of UHPC is the smallest,which is 49.7%lower than that of the baseline group.The autogenous shrinkage rate and drying shrinkage rate prediction models are in good agreement with the test results,and can be used to predict the shrinkage development of recycled brick powder UHPC.
recycled brick powderUHPCautogenous shrinkagedrying shrinkageshrinkage rate prediction model
万方数据
维普
