高韧性纤维水泥稳定碎石路用性能研究

Study on Pavement Performance of High-toughness Fiber Cement Stabilized Gravel

摘要:

反射裂缝是沥青路面半刚性基层中常有出现的问题，研究提出将自主研发的特种高韧性纤维掺入到水泥稳定碎石中，达到改善其抗裂性能的目的，通过测定多种纤维掺量水泥稳定碎石的无侧限抗压强度、劈裂强度、单轴压缩模量及收缩系数，分析该特种高韧性纤维对水稳碎石材料性能影响的变化规律。试验结果表明：随着纤维掺量逐渐大，水泥稳定碎石养护7、28、90 d的无侧限抗压强度和劈裂强度均呈现先增大后减小的趋势，且各种指标强度均在1‰纤维掺量时最大，单轴压缩模量在2‰下有最大值。养护90 d的无侧限抗压强度和劈裂强度在掺入1‰纤维后分别提高14.1％和9％；掺加特种高韧性纤维能够改善水稳碎石材料的收缩性能，纤维掺量为1‰时，温缩系数和干缩系数分别比不掺时提高14.1％和12.8％。

Abstract:

Reflective crack is a common problem in semi-rigid base of asphalt pavement. It is proposed to incorporate the self-developed special high-toughness fiber into the cement stabilized gravel to improve its crack resistance. By measuring the unconfined compressive strength, splitting strength, uniaxial compressive modulus and shrinkage coefficient of cement stabilized gravel with various fiber contents, the variation influence law of this fiber on the performance of cement stabilized gravel is analyzed. The test results show that with the increase of fiber content, the unconfined compressive strength and splitting strength of cement stabilized gravel at 7 d, 28 d and 90 d increase first and then decrease, and the strength of each index is the largest when the fiber content is 1 ‰, and the uniaxial compression modulus has a maximum value at 2 ‰. The unconfined compressive strength and splitting strength of 90 d are increased by 14.1 % and 9 % respectively after adding 1 ‰ fiber. The shrinkage performance of cement stabilized gravel can be improved by adding the special high-toughness fiber. When the fiber content is 1 ‰, the temperature shrinkage coefficient and the dry shrinkage coefficient are increased by 14.1 % and 12.8% respectively compared with those without fiber.