纤维级配碎石性能研究

Study on Technical Performance of Fiber Graded Crushed Rock

关键词:  道路工程  级配碎石  纤维  抗剪强度  抗车辙能力

Key words:  highway engineering  graded crushed rock  fiber  shear strength  rutting resistance

摘要:

在级配碎石中掺加纤维，以提高其路用性能；采用振动成型方法，以劈裂强度为标准，优化了纤维种类、掺量及长度；采用自行开发的级配碎石剪切仪，系统研究了纤维级配碎石抗剪强度的影响因素；同时，对纤维级配碎石的抗车辙能力进行了研究.结果表明：在50kPa的围压下，掺加纤维的级配碎石抗剪强度最大可提高27倍；含水量增大，纤维级配碎石抗剪强度减小；压实度提高，纤维级配碎石抗剪强度增大；相比之下，小粒径纤维级配碎石抗剪强度较大；纤维的掺加显著提高了级配碎石的抗车辙能力；优化的纤维能够均匀分散于级配碎石混合料中；纤维级配碎石基层路表弯沉小于普通级配碎石基层的路表弯沉，表明这种柔性路面可用于重载交通.

Abstract:

To improve the graded crushed rock road performance, a new technical measure was taken to add the fibers to graded crushed rock mixtures. Using vibration as molding method and splitting strength as the standard, the type, dosage and length of fiber were optimized. Using the self developed graded crushed rock shear apparatus, the influence factors of the shear strength of fiber graded crushed rock were systematically studied. At the same time, the fiber graded crushed rocks rutting resistance performance was studied. The experiment results show that when the confining pressure is 50kPa, the fiber graded crushed rock maximum shear strength can be increased by 27 times; water content, compaction degree and maximum particle size have significant effects on the shear strength; with the water content increasing, the shear strength decreases; the greater degree of compaction, the bigger the shear strength becomes; the fiber graded crushed rock with small particle size has a bigger shear strength. Rutting test results show that the adding of fibers significantly improved the rutting resistance of graded crushed rock. Construction test results show that the fibers self developed can be evenly dispersed in the graded crushed rock mixtures; the surface deflection of the fiber graded crushed rock base is less than that of the ordinary graded crushed rock base; it has also been shown that fiber graded crushed stone flexible pavement can be used for heavy traffic.