基于大厚度半刚性基层配合比试验分析

Experimental Analysis of Mix Ratio of Large-thickness Semi-rigid Base

以某干线公路为研究背景,采用一定比例组合的混合料,通过强度和密度试验,以集料之间的内摩擦阻力及密实度为评定标准,对混合料中的粗集料和粗细集料配合比进行分析,研究其对大厚度半刚性基层的性能影响。结果表明:在填充振实试验中,粗集料A_(0)、A_(1)、A_(2)组比例分别为31.5∶38.5∶30和35∶35∶30时的振实密度较高;在7 d无侧限抗压强度试验中,混合料内的粗细集料比例为75∶25时的嵌挤强度最高;在配合比分析中,大厚度半刚性基层构成骨架密实型结构的关键筛孔尺寸为9.5、4.75、2.36 mm,该尺寸下通过率范围分别为50%~57%、33%~38%、19%~25%。

A certain trunk road is taken as the research background and also a certain proportion of the mixture is used to analyze the mix ratio of the coarse aggregate and the coarse and fine aggregate in the mixture and study its influence on the performance of large-thickness semi-rigid base through the strength and density tests and the internal friction resistance and density between the aggregates as the evaluation criteria.It is concluded that in the filling vibration test,when the proportions of the coarse aggregate A_(0),A_(1) and A_(2) groups are 31.5∶38.5∶30 and 35∶35∶30 respectively,the tap density is high;in the 7 days unconfined compressive strength test,the squeeze strength is the highest when the ratio of thick and fine aggregates in the mixture is 75∶25;in the mix ratio analysis,a large thickness semi-rigid base is used to form the skeleton,the key sieve size of the compact structure is 9.5,4.75 and 2.36 mm,and the pass rate range under this size is controlled to be 50%-57%,33%-38% and 19%-25%respectively.