寒区公路水泥稳定砂砾基层强度试验研究

EXPERIMENTAL STUDY ON STRENGTH OF CEMENT STABILIZED SAND GRAVEL BASE OF HIGH WAY IN COLD AREA

在寒区交通荷载和温度荷载的重复作用下,水泥稳定砂砾基层的这种收缩裂缝很容易扩展到沥青面层而形成反射裂缝。为分析水泥稳定砂砾基层强度,通过试验设计几组不同粗细粒径的水泥稳定砂砾级配,进行水泥稳定砂砾的无侧限抗压强度、劈裂强度试验,通过试验研究养生龄期、级配类型对试件劈裂强度的影响,分析养生龄期、水泥剂量、级配类型对试件抗裂性能的影响规律。研究表明提高水泥剂量或采用嵌挤良好的级配类型均可以提高试件的强度,养生初期是试件劈裂强度增长的关键时期,养生龄期14d之后劈裂强度的增长速率放缓。

Under the repeated action of traffic load and temperature load in cold area,the shrinkage crack of cement stabilized sand gravel base is easy to expand to the asphalt surface and form a reflection crack.In order to analyze the strength of cement stabilized gravel base,the author designed several groups of cement stabilized gravel gradation with different thickness and carried out experiments on unconfined compressive strength and splitting strength of cement stabilized gravel,and studied the influence of health age and grading type on the splitting strength of specimens through experiments.The effects of curing age,cement dosage and grade type on crack resistance of specimens were analyzed.The results show that the strength of the specimen can be improved by increasing the dosage of cement or us⁃ing the grade type with good intercalation.The key period for the growth of the splitting strength of the specimen is in the early stage of curing,and the growth rate of the splitting strength slows down after 14 days of curing.