红砂岩集料对水稳基层强度与抗软化性能的影响

红砂岩具有遇水软化的特性,通过与石灰岩集料对比,研究了红砂岩粗、细集料硬度与抗软化性能及其对水泥稳定基层(水稳基层)强度与抗软化性能的影响规律,并通过界限含水率、XRD与SEM测试,对比了红砂岩、石灰岩集料浸水前后的矿物成分与微观形貌。结果表明,红砂岩集料浸水后质量减少,硬度降低,抗软化性变差,制备的红砂岩水稳基层强度、软化系数低于石灰岩水稳基层,但红砂岩粗集料制备的水稳基层强度、软化系数降低幅度小于红砂岩细集料制备的水稳基层。红砂岩集料中的黏土矿物遇水崩解剥落、膨胀疏松化是红砂岩水稳基层强度、软化系数降低的主要原因。本研究可以为红砂岩在路面基层材料中的组成设计与工程应用提供理论参考。

Influence of Red Sandstone Aggregate on Strength and Softening Resistance Performance of Cement Stabilized Base

Red sandstone has the characteristic of water softening. By comparing with limestone aggregate, the hardness and softening resistance performance of coarse and fine aggregate of red sandstone were studied. Then the influence law of red sandstone aggregate on the strength and softening resistance performance ofcement stabilized base were studied. The mineral composition and microstructure of red sandstone and limestone aggregate before and after immersion were compared by boundary moisture content measurement, XRD and SEM examination. The results show that the weight and hardness of red sandstone aggregate decrease after immersion, and the softening resistance performance becomes worse. The strength and softening coefficient of cement stabilized red sandstone base are lower than those ofcement stabilized limestone base, but the decreasing degree of strength and softening coefficient of cement stabilized red sandstone coarse aggregate base is less than those of cement stabilized red sandstone fine aggregate base. The main reason for the decrease of strength and softening coefficient of cement stabilized red sandstone base is that clay minerals in red sandstone aggregate are disintegrated and expanded in water. This study provides theoretical reference for the composition design and application of red sandstone in pavement base.