固化剂对水泥稳定粗砂的水稳定性影响研究

Study on the Influence of Curing Agent on the Water Stability of Cement-stabilized Coarse Sand

水泥稳定粗砂作为一种道路基层材料,其水稳定性直接影响路面结构的使用性能与耐久性。为探究固化剂对水泥稳定粗砂水稳定性的影响,制备了5种水泥稳定粗砂试件(S6,0.04、S8,0.04、S10,0.04、S10、S12),结合浸水试验、冻融循环试验和扫描电镜试验,分别从宏观和微观角度分析了试件的无侧限抗压强度变化规律及强度劣化机理。研究结果表明:浸水1 d后,5种试件的无侧限抗压强度均呈不同程度的增加;28 d养护龄期下,随着冻融循环次数的增加,5种试件的无侧限抗压强度呈现出减小—增加—减小的变化规律;水泥掺量为10%时,添加固化剂的试件浸水强度和抗冻融强度远大于未添加固化剂的试件;随着冻融循环次数的增加,试件S10,0.04颗粒间的粘结减弱,孔隙数量增加,导致强度下降。因此,添加一定量的固化剂,可有效提高水泥稳定粗砂在浸水和冻融循环条件下的稳定性,从而提高其作为道路基层材料的耐久性。

As a type of road base material,cement-stabilized coarse sand has a direct impact on the performance and durability of the pavement structure due to its water stability.In order to investigate the effect of curing agents on the water stability of cement stabilized coarse sand,five types of cement-stabilized coarse sand specimens(S6,0.04 S8,0.04、S10,0.04,S10,S12)were prepared.By combining immersion test,freeze-thaw cycle test,and scanning electron microscopy test,the strength variation law and strength degradation mechanism of the unconfined compressive strength of the specimens were analyzed from both macroscopic and microscopic perspectives.The research results show that after soaking in water for 1 day,the unconfined compressive strength of the five specimens increased to varying degrees;Under a curing age of 28 days,with the increase of freeze-thaw cycles,the unconfined compressive strength of the five specimens showed a variation law of reducing-increasing-reducing;When the cement content is 10%,the immersion strength and freeze-thaw resistance of the specimens with added curing agent are much higher than those without curing agent;With the number of freeze-thaw cycles increases,the connection between particles of specimen S10,0.04 particle weakens,the number of pores increases,and the strength decreases.Therefore,adding a certain amount of curing agent can effectively improve the stability of cement stabilized coarse sand under immersion and freeze-thaw cycles to enhance its durability as road base materials.