关键词: 再生混凝土;普通强制搅拌;振动搅拌;机理;混凝土性能

Abstract: A new method vibratory mixing was put forward to overcome defects of recycled aggregates and improve the performance of recycled concrete , the effect of vibratory mixing on performance of freshly mixed recycled concrete and mechanical property were investigated based on the characteristics of recycled aggregate and vibratory mixing , the vibration mixing mechanism of recycled aggregate concrete was analyzed.The performance of ordinary forced mixing and vibratory mixing concrete with different recycled aggregate content was compared .The results show that the apparent density and the air content of vibratory mixed recycled concrete is increased when compared with that of ordinary forced mixing , the increased air content is helpful to improve the durability of recycled concrete .The slump is the same as that of ordinary forced mixing concrete, which is indicated that vibratory mixing solve the problem of recycled concrete poor workability.The 28 d compressive strength of 25％ and 50％ recycled aggregates concrete by vibratory mixing increased by 21.9％ and 13.4％ when compared with that of ordinary forced mixing recycled concrete, the coefficient of variation is reduced at the same time .From the view of microstructure, vibration improves the uniformity of the hydration reaction , generates more cluster C-S-H gels, this change improves the microstructure and strength of recycled concrete .The research shows that vibratory mixing can improve the comprehensive performance of recycled concrete .

Key words: recycled concrete;ordinary forced mixing;vibratory mixing;mechanism;concrete performance