掺超细粉煤灰高性能混凝土Ⅲ型轨枕的力学性能试验研究

Experimental Research on the Mechanical Properties of Type Ⅲ Sleeper of Ultra-pulverized Fly Ash

对掺超细粉煤灰的HPC Ⅲ型轨枕和普通C Ⅲ型轨枕的力学性能,如枕中和枕下截面的抗裂、极限承载力、轨枕端部局压和轨枕的疲劳性能进行了对比试验研究。试验表明,各种龄期HPC Ⅲ型轨枕与C Ⅲ型轨枕枕中和枕下的开裂荷载与极限承载力均比较接近,满足标准的要求。还对轨枕端部进行了非线性有限元分析,分析很好地验证了试验结果,分析与试验结果均表明,轨枕端头局压破坏为主拉劈裂破坏,试验实测的超细粉煤灰HPC Ⅲ型轨枕端部局压的极限承载力远大于锚固板设计最大张拉预应力,有较大的安全储备。HPC Ⅲ型轨枕的疲劳性能与C Ⅲ型轨枕的相近,HPC Ⅲ型轨枕的疲劳残余裂缝宽度略小于C Ⅲ型轨枕。

This paper reports the mechanical properties of Type Ⅲ sleepers of Ultra-pulverized Fly Ash(HPC-Ⅲsleepers) and Type Ⅲ sleepers(C-Ⅲ sleepers), such as the cracking loads and ultimate loads at the middle and bottom sections, the pressures at the ends and the fatigue properties. It is found by experiment that the HPC-Ⅲ sleepers are similar to the C-Ⅲ sleepers in the cracking loads and ultimate loads and the fatigue properties at the middle and bottom sections. The non-linear analysis of the anchor parts of Type Ⅲ sleepers agrees with the experimental result, the experimental ultimate load beneath the anchor parts being larger than the load applied by the prestressing steel on the anchor parts. The crack of the HPC-Ⅲ sleeper in the process of fatigue experiment is narrower than that of the C-Ⅲ sleeper.