基于抗变形能力的级配碎石组成设计方法

级配碎石的主要缺陷是易产生较大的塑性变形。在分析现行级配组成设计方法的基础上,根据连续密级配碎石的加州承载比(CBR)试验和利用研制的柔性材料剪切性能测试仪进行的剪切性能试验结果,对基于抗变形能力的级配碎石组成设计方法进行了研究。结果表明:以CBR值和剪切强度为组成设计的性能控制参数,CBR值应不小于180%,剪切强度应大于0.52 MPa;以最大粒径、泰波(Taibol)级配指数n值和基于双指标控制的关键筛孔及其通过率合理变化范围作为级配控制参数,最大粒径宜为31.5 mm,要求不高时可以放宽到37.5 mm;n值控制在0.45~0.50之间,以0.50为宜;4.75、2.36、0.60、0.075 mm筛孔应作为关键筛孔予以控制;通过率应在基于双指标控制的合理变化范围内。由此提出了基于抗变形能力的级配碎石组成设计方法,通过试验路应用表明,该设计方法可以有效控制级配碎石的塑性变形。

Graded and broken stone composing design method based on deformation resistance

The primary disadvantage of the graded and broken stone is easy to lead the obvious plastic deformation.According to the testing results of CBR and the shear performance using the flexible material shear performance tester,the composing design method based on deformation resistance was studied.The result indicates that: it should take CBR and the shear strength as the performance controls parameter during the design;CBR should not be less than 180%,and shear strength should be greater than 0.52 MPa;it should take the maximum grain size,n value of Taibol equation,key sieve pores and its rational change range as the grade controls parameter;the maximum grain size should be 31.5 mm,may be broaden to 37.5 mm while request isn't high;the n value should be controlled between 0.45 and 0.50,suitably is 0.5;some sieve pores as 4.75 mm,2.36 mm,0.60 mm,0.075 mm,should be controlled as key sieve pores,their passing rate should be within the rational change range based on the double control index.The graded and broken stone composing design method based on deformation resistance was put forward.The testing road shows that the design method can effectively control the plastic deformation of graded and broken stone.4 tabs,5 figs,10 refs.