预应力钢纤维高强混凝土特种轨枕的疲劳特性

采用双重和多重复合技术， 在预应力高强混凝土轨枕的基础上分别制备了预应力钢纤维高强混凝土和预应力钢纤维硅灰高强混凝土特种轨枕；在５００ ｋＮ 伺服液压疲劳试验机上测试了三个系列轨枕疲劳荷载时裂缝宽度和高度的变化规律．研究结果表明，由于钢纤维的阻裂效应，显著提高了高强混凝土轨枕的抗疲劳性能；再因硅灰的填充效应、微集料效应和火山灰效应改善了高强混凝土内部的微观结构，尤其是界面结构， 使预应力钢纤维高强混凝土轨枕的抗疲劳性能进一步提高．该轨枕不仅可用于特殊应力下承担复杂荷载，而且可带裂缝工作．

Study on the Fatigue Characteristics of Pre stressed Steel Fiber High Strength Concrete

The double and multiple composite techniques were applied to make the pre stressed steel fiber high strength concrete sleeper and the pre stressed steel fiber and silica fume high strength concrete sleeper. The change regularity of crack width and height of three series of sleepers loaded fatigue loading were tested in a 500?kN servo hydraulic fatigue test machine. The study results demonstrated that the fatigue performance of SFPRHSC sleeper was enhanced obviously because of the resistance effect of steel fiber. The fatigue performance of SFSIFUPRHSC sleeper were enhanced further because of the improvement of concrete microstructure resulted by the pozzolanic effect, crystallite effect and micro aggregate effect of silica fume. The SFPRHSC sleeper not only can load complex loading in specific stress, but also can work with cracks.