多孔火山岩骨料混凝土轨枕疲劳裂缝扩展研究

为研究多孔火山岩粗骨料混凝土轨枕在东非地区铁路轨道工程中应用的可行性,对其进行了疲劳试验,利用三维光学应变测量仪和裂缝测宽仪对轨枕疲劳试验中产生的裂纹高度和宽度进行测量,研究轨枕疲劳裂纹扩展规律。研究发现:疲劳裂纹扩展速率呈现明显的非线性特征,多数情况下最终裂纹高度小于中和轴高度;最大残余裂纹宽度小于0. 05 mm,满足规范要求。表明多孔火山岩骨料混凝土轨枕疲劳性能满足中国现行规范要求,可在东非地区推广应用。

Study on Fatigue Crack Propagation of Porous Volcanic Aggregate Concrete Sleepers

To study the feasibility of using porous volcanic coarse aggregate concrete sleepers in railway track engineering in East Africa region,the fatigue test was carried out,the height and width of cracks in sleeper fatigue test were measured by three-dimensional optical strain gauge and crack width gauge,and the fatigue crack propagation law of sleeper was studied.The results show that the fatigue crack propagation rate shows obvious non-linear characteristics and the f inal crack height is less than the neutral axis height in most cases,and the maximum residual crack width is less than 0.05 mm,which meets the requirements of the code.The work presented in this paper indicate that the fatigue properties of porous volcanic aggregate concrete sleepers meet the requirements of current Chinese codes and can be popularized and applied in East Africa.