ABSTRACT
The performances of regenerative aggregate from construction solid waste are weaker than those of natural aggregate, which degrades the working performance and durability of regenerative aggregate concrete, and limit its application in practical engineering. Therefore, in this paper, the effects of the replacement rate (0, 20%, 40%, and 60%) of regenerative aggregate on the strength, electrical flux, and chloride ion penetration resistance of fresh concrete under the freeze-thaw cycle are studied. The experimental results show that compared with ordinary concrete, when the replacement rate of recycled fine aggregate is 20%, 40%, and 60%, the electric flux of concrete increases by 20.17%, 33.29%, and 66.9%, respectively, and the diffusion coefficient of chloride ion increases by 22.47%, 42.58% and 73.87%, respectively. When the freezing-thawing cycle is 100 times, the reduction of the mass of RAC60 is 23.33%, and the disadvantage of recycled concrete is obvious. Moreover, with the enhancing the substitution rate of regenerative aggregate, the ability of concrete to resist freezing-thawing becomes weaker under 50 cycles. The reduction of elastic modulus is 5.18% without substitution. It is 9.05% under substitution of 60%, and the loss rate increases by 74.7%. These provide the basis for various application scenarios of recycled aggregate from building solid waste.
