混凝土再生集料水泥稳定碎石强度及影响因素研究

Study on strength and influencing factors of cement stabilized macadam with recycled concrete aggregates

在半刚性基层中使用再生集料是废旧水泥混凝土再生利用的一个有效途径,为提高水泥稳定再生集料基层的强度,结合柳南高速公路改扩建工程设计了2种再生集料水泥稳定碎石的配合比方案,通过室内试验评价其路用性能。结果表明:再生粗细集料能够用于高速公路(底)基层;再生集料的比例越高,水泥稳定碎石的最佳含水量越大;细集料吸水率大小主要影响水稳碎石的最佳含水量;当水泥用量小于4.5%时,再生方案的抗压强度小于优化方案;当水泥用量大于4.5%时,两方案的抗压强度基本一致;水泥用量每增加0.5%,再生细集料对水稳碎石强度的影响便降低约1.45%。

The application of recycled concrete aggregates in semi-rigid base is an effective way to recycle wasted concrete.In order to improve the strength of cement stabilized recycled aggregate base,two kinds of cement stabilized macadam using recycled aggregate were designed based on the expansion project of Nanning-Liuzhou Expressway and its performance was evaluated through laboratory tests.Test results indicated that the coarse and fine recycled concrete aggregates were suitable to be used in the base and sub-base of highway.The optimum moisture content of cement stabilized macadam increased with the increase of recycled aggregate ratio.The water absorption of fine aggregate mainly affects the optimum moisture content of cement stabilized macadam.When the cement content was less than 4.5%,the compressive strength of optimization design was better than the original design.When the cement content was more than 4.5%,the compressive strength was basically the same in both original design and optimization design.When the cement content consumption was increased by 0.5%,the impact of recycled fine aggregate on compressive strength will be reduced by about 1.45%.