贵阳—清镇高速公路红粘土强度指标性能试验

Experimental Research of Strength Index of Red Clay for Guiyang-Qingzhen Expressway

以贵阳—清镇高速公路为依托工程,采用室内承载板法分析了红粘土压实度、含水率、稠度、龄期与回弹模量的关系,以及最不利条件下,回弹模量与压实度的关系。采用路面材料强度仪进行了未泡水的CBR试验、泡水24、48 h和96 h的CBR试验。结果表明,红粘土回弹模量与含水率关系可以用幂函数拟合;回弹模量与压实度和稠度指标具有良好的相关关系,不同地区不同土质其回归关系是不相同的;随着土样含水率的增大,红粘土未泡水CBR值先增大后减小,在最佳含水率下CBR值达到最大。试样初始含水率对CBR值影响较小;泡水24 h和48 h时,CBR值能满足规范要求,泡水96 h时CBR值不能满足规范中对各等级公路CBR值的要求。

Based on Guiyang-Qingzhen Expressway construction project,using indoor loading plate,the relations of resilent modulus with physical indexes of red clay such as compaction degree,water content,consistency and age were analyzed.The relation between resilent modulus and compaction degree under the worst unfavourable condition was also tested.Using pave material strength instrument,a serials of CBR tests under the conditions of unimmersion,immersed for 24 h,48 h and 96 h were performed.The results show that（1） the relation between resilent modulus and water content can be expressed with the power function;（2） the relation of resilent modulus with consistency and compaction can also be expressed with functions,but the regression functions are different for the different areas and different clays;（3） the CBR value of unimmersd red clay increases at first and then decreases when water content increases,and the CBR value reaches maximum with the optimization water content;（4）the influence of original water content on CBR value is little;（5） the CBR value can meet the requirement of specification under the condition of immersed for 24 h and 48 h,but the CBR value immersed for 96 h cannot meet the requirement of specification for different roads.