聚丙烯纤维水泥稳定碎石收缩性能

为了减小水泥稳定碎石的收缩, 研究了聚丙烯纤维对水泥稳定碎石收缩性能的影响, 分别用千分表支架法和应变片电测法对聚丙烯纤维水泥稳定碎石和普通水泥稳定碎石的干缩性能和温缩性能进行了测试, 分析了材料的平均干缩系数和平均温缩系数随纤维掺量变化的规律。试验结果表明: 聚丙烯纤维的掺入可显著地减小水泥稳定碎石的平均干缩系数和平均温缩系数, 高龄期聚丙烯纤维水泥稳定碎石的平均干缩系数比低龄期的小, 而高龄期的平均温缩系数却比低龄期的大; 在纤维体积掺量小于1‰的范围内, 随着纤维体积掺量的增加, 水泥稳定碎石平均干缩系数和平均温缩系数均逐渐减小。可见, 在一定的纤维掺量范围内, 聚丙烯纤维水泥稳定碎石具有良好的抗收缩性能, 应用于路面基层可提高路面的抗裂性能。

Shrinkage properties of cement stabilized macadam reinforced with polypropylene fiber

In order to decrease the shrinkage of cement stabilized macadam, the influences of polypropylene fiber on the shrinkage properties of cement stabilized macadam were studied, its dry shrinkage property was measured by using micrometer gauge method, and its thermal shrinkage property was measured by using strain gauge method, the rules of its average dry shrinkage coefficient and average thermal shrinkage coefficient with the variation of the fiber volume content were analyzed.Test result shows that the addition of polypropylene fiber can observabley decreases the average dry shrinkage coefficient and average thermal shrinkage coefficient, the average dry shrinkage coefficient of long curing period is smaller than that of short curing period, while the average thermal shrinkage coefficient of long curing period is larger than that of short curing period.When the fiber volume content is less than 1‰, the average dry shrinkage coefficient and average thermal shrinkage coefficient observably decrease with the increase of polypropylene fiber dosage.So cement stabilized macadam reinforced with polypropylene fiber has favorable resistance on dry shrinkage and thermal shrinkage when the fiber volume content is appropiate, and its application in base course can improve the anti-cracking performance of pavement.