水泥稳定再生集料的力学特性及影响因素研究

Study on Mechanical Property and Influencing Factors of Cement Stabilized Recycled Aggregate

旨在揭示水泥稳定再生集料(CSRA)的力学特性及其影响因素。设计了4种不同RCA掺量的CSRA,测试其击实特性、抗压强度、抗压回弹模量、劈裂强度与弯拉强度,并建立强度增长方程及力学指标间的关系方程。结果表明,利用废弃混凝土能够生产出满足现行规范要求的再生集料(RCA),且RCA中含有一定活性的硅酸盐,对CSRA的力学特性存在有利影响。当龄期小于60 d时,CSRA的无侧限抗压强度与抗压回弹模量随RCA掺量的增加先降低后增大,当龄期为90 d时,则随RCA掺量的增加而降低。CSRA的劈裂强度与弯拉强度随RCA掺量的增加而增大。所建立的CSRA强度增长方程可较为精确地表征强度增长特性;当试验条件受限时,利用力学指标关系方程可预估其他力学指标。CSRA用于路面基层中,无侧限抗压强度与劈裂强度满足现行规范要求,RCA掺量可达100%。

In order to reveal the mechanical property of cement stabilized recycled aggregate（CSRA） and influencing factors,4 kinds of CSRA with different proportions of recycled concrete aggregate（RCA） are designed,the compaction property,compressive strength,compressive resilient modulus,spitting strength and flexural tensile strength are tested,and the strength growing equation and the relationship equation of mechanical parameters are established. The result shows that（1） the RCA produced with waste concrete can meet the requirements of current specifications,and has some beneficial effect on the mechanical property of CSRA because it contains silicate with certain activity;（2） when the curing age is less than 60 d,the unconfined compressive strength and compressive resilient modulus of CSRA first increase and then decrease with the increasing of RCA content,and they decrease with the increasing of RCA content when the curing age is 90 d;（3） the splitting strength and flexural strength of CSRA increase with the increasing of RCA content;（4） the established strength growth equation can more accurately predict the growth characteristics of strength of CSRA,and when experimental condition is limited,the other mechanical indicators of CSRA can be estimated using the established relationship equation of CSRA mechanical indicators;（5） UCS andsplitting strength can meet the requirements of current specifications when CSRA is applied in pavement base,and the RCA content can be up to 100%.