水泥稳定再生骨料混合料力学性能和抗冻性能研究

Mechanical Properties and Frost Resistance of Cement Stabilized Recycled Aggregate Mixture

为促进再生骨料在半刚性基层中的应用,实现建筑垃圾在公路工程中的资源化利用,本文采用等质量置换法,系统分析了再生骨料掺量(质量分数)为0%、30%、50%、70%、100%时对无机混合料最大干密度、最佳含水率、无侧限抗压强度、抗冻性能的影响,并从微观角度解释了内在影响机理。结果表明:掺入再生骨料降低了无机混合料的最大干密度,增大了最佳含水率;再生骨料可以有效提高无机混合料的无侧限抗压强度和抗冻性能,当再生骨料掺量为70%时提升效果最佳,此时再生骨料无机混合料7、28 d无侧限抗压强度为4.6、6.8 MPa, 28、90 d冻融循环后残留抗压强度比可达82.4%、85.5%。

In order to promote the application of recycled aggregate in semi rigid base layers and achieve the resource utilization of construction waste in highway engineering,this article uses equal mass replacement method to systematically analyze the effect of recycled aggregate content(mass fraction)at 0%,30%,50%,70%,and 100%on maximum dry density,optimal moisture content,unconfined compressive strength,and frost resistance of inorganic mixtures,and explains its internal influencing mechanism from a microscopic perspective.The results show that the addition of recycled aggregate reduces the maximum dry density of inorganic mixtures and increases the optimal moisture content.Recycled aggregate can effectively improve the unconfined compressive strength and frost resistance of inorganic mixtures.The best effect is achieved when recycled aggregate content is 70%.At this moment,the unconfined compressive strength of recycled aggregate inorganic mixtures is 4.6 and 6.8 MPa after 7 and 28 d,and the residual compressive strength ratio after 28 and 90 d of freeze-thaw cycles can reach 82.4%and 85.5%.