水稳碎石基层膨胀性与收缩性对比分析

Comparative analysis of expansibility and contractility of cement stabilized macadam base

为了分析水稳碎石基层隆起病害成因,通过公路工程无机结合料稳定材料试验计算水稳碎石混合料在温度为10~60℃升温过程的膨胀系数,并与这一温度区间降温过程的温缩系数进行比较。设计了固定单一因素的控制变量法和正交试验法这2种试验方案,对混合料的膨胀和收缩规律进行分析。结果表明:级配类型、水泥剂量、养生龄期为影响水稳碎石混合料膨胀性和温缩性的主要因素,其中级配类型影响最大,而硫酸盐含量影响不大;各因素下水稳碎石混合料的温缩系数均大于膨胀系数,表明该类材料以温度收缩开裂病害为主,同时应根据影响混合料膨胀系数的因素来选定级配类型、水泥剂量等。

This article tries to analyze the cause of the transverse uplift diseases,in the temperature range of 10-60℃,compared the swelling coefficient of cement stabilized macadam mixture in the heating process with the shrinkage coefficient in the cooling process,which was calculated by the test of inorganic binder stabilized material in highway engineering.In order to facilitate the analysis,two kinds of schemes were designed in the test,which were control variable method of fixing single factor and orthogonal test method respectively.The expansion and shrinkage of the mixture were analyzed.The results show that gradation type,cement dosage and curing age are the main factors affecting the expansibility and contractility of cement stabilized macadam mixture,among which gradation type has the greatest influence,while sulfate content has little influence;the temperature shrinkage coefficient of cement stabilized macadam mixture is greater than the expansion coefficient,which indicates that this kind of material is still dominated by temperature shrinkage cracking disease,and it should be based on the factors that affect the expansion coefficient of the mixture to select gradation type and cement dosage,etc.