Durability of Recycled Brick Powder ECC under Salt-Freezing Coupling Environment
Recycled brick powder engineered cementitious composites(ECC)was prepared by replacing quartz sand in ECC with recycled brick powder.The mass loss rate and relative dynamic elastic modulus of recycled brick powder ECC under the erosion of NaCl solution,Na2SO4 solution and NaCl+Na2SO4 solution were studied by rapid freeze-thaw test of concrete.The damage model of ECC under salt frost erosion environment was established,and its durability was evaluated.The results show that after 300 freeze-thaw cycles,the mass loss rates of recycled brick powder ECC in water,NaCl salt solution,Na2SO4 solution and NaCl+Na2SO4 salt solution are 2.884％,4.984％,1.955％and 6.891％,respectively.The relative dynamic elastic modulus decreases by 6.468％,16.300％,24.303％and 39.861％,respectively.The frost resistance grade of recycled brick powder ECC is greater than F300 in the case of single salt-freezing,and the frost resistance grade is greater than F250 in the case of composite salt-freezing,which has good salt-freezing resistance.The established freeze-thaw damage model can better reflect the relationship between the damage degree Dn of ECC under different freeze-thaw media and the number of freeze-thaw cycles,which can provide an effective reference for structural durability design in severe cold regions.
recycled brick powderengineered cementitious compositesalt erosionfreeze-thaw cyclemass loss raterelative dynamic elastic modulusfreeze-thaw damage model
万方数据
维普
