中文摘要：

为了研究聚丙烯纤维（PPF）水泥稳定砂砾的干缩、温缩和低温冻融性能，基于PPF长度和掺量变化．通过室内试验考察了不同龄期各组试件的上述物理力学性能，得到了PPF长度和掺量变化下的影响规律，并从材料组成的微观、宏观以及断裂力学角度分析了其机理。结果表明，各龄期PPF水泥稳定砂砾的干缩和温缩系数均随PPF长度、掺量的增加而减小；PPF对水泥稳定砂砾低温性能的改善幅度，随PPF长度的增加呈递增趋势，而随PPF掺量增加的改善趋势会因PPF长度的不同而表现各畀：PPF长度较小时呈递增趋势，长度较大时呈先增加后减小趋势。研究给出了合理的PPF长度及掺量取值，与普通对比组相比，PPF组的平均干缩系数和温缩系数可分别降低19．4％和12．1％以上；冻融抗压强度和劈裂强度可分别提高12．1％和16．7％以上，冻融质量损失率可降低87．8％以上。

英文摘要：

To study the dry shrinkage performance, temperature shrinkage performance and low-temperature freezing-thawing performance of PPF reinforced cement-stabilized gravel, under the conditions of changing parameters which are the length and mixing amount of PPF, the physical and mechanical properties of every group of the specimens with different ages are investigated by laboratory test, and its mechanism is analyzed from the perspectives of microscopic and macroscopic structure of the material and also of the fracture mechanics. The result shows that （1） as the length and mixing amount of PPF increase, both the coefficients of dry shrinkage and temperature shrinkage of PPF reinforced cement-stabilized gravel with different ages decrease; （2） the improvement of PPF to the low-temperature performance of cement-stabilized gravel enhances with the increasing of the length of PPF, while the improvement of the increase of mixing amount of PPF to the gravel behaves differently according to the length of PPF： when the length of PPF is short, the improvement enhances, when the length is long, the improvement increases firstly and decreases later. The research proposed the appropriate length and mixing amount of PPF. Comparing with the common group, the average coefficients of dry shrinkage and temperature shrinkage in the group using PPF decreased by more than 19.4% and 12. 1% , the freezing-thawing compressive strength and splitting strength increased by morethan 12. 1% and 16.7% , and the freezing-thawing mass loss can be decreased by more than 87.8%.