Abstract：The physical abrasion method and the chemical reagent spraying method were used to strengthen the engineering properties of recycled aggregates from cement concrete pavement slabs. The effects of steel balls number, rotation circle, reagent type, reagent content and mixing time on water absorption and crushing value of recycled aggregates were evaluated. The microstructure of recycled aggregates was scanned before and after strengthening. The results show that the engineering properties of recycled aggregates can be significantly improved by the physical and chemical strengthening methods. The optimum condition for the abrasion test is obtained with 8 steel balls for 300 circles, and the optimum chemical strengthening reagent is organic silicon resin. The optimum content and the mixing time are 2% and 30 s, respectively. The hardened cement paste on the surface of recycled aggregates can be removed by the physical abrasion. The microscopic damage of recycled aggregates can be repaired by the film formation of chemical reagent. The water absorption and the crushing value of recycled aggregates can be effectively reduced by these methods.
2019, Vol. 40 
