气泡参数对无砟轨道支承层混凝土抗冻能力影响分析  

Analysis of the Influence of Bubble Parameters on the Frost Resistance of Ballastless Track Slab Concrete

作　　者：杨怀志 刘学文 杨志强 YANG Huaizhi;LIU Xuewen;YANG Zhiqiang(Beijing-Shanghai High Speed Railway Ltd.Company,Beijing 100038,China;Southeast University,Nanjing 210089,China)

机构地区：[1]京沪高速铁路股份有限公司,北京100038 [2]东南大学,江苏南京210089

出　　处：《国防交通工程与技术》2024年第6期20-24,共5页Traffic Engineering and Technology for National Defence

基　　金：中国铁路总公司科技研究开发计划(P2018G005)。

摘　　要：冻融循环作用是导致寒区板式无砟轨道支承层服役性能下降的主要因素之一。制备了C10、C15低强度混凝土及Ca10、Ca15低强度引气混凝土,分析了支承层混凝土含气量、气孔结构特征以及抗压强度变化规律,研究了冻融循环下含气量对支承层混凝土抗压强度、质量损失及相对动弹性模量的影响。研究表明:支承层混凝土强度等级和含气量是影响抗冻能力的主要因素,适当提高混凝土强度等级和含气量,可显著增加其抗冻能力;硬化混凝土气泡间距系数与支承层抗冻性能具有良好的相关性,采用气泡间距系数可较好的评价低强度等级支承层混凝土的抗冻性能。基于冻融循环作用后混凝土力学性能演变规律建立了支承层混凝土冻融损伤预测模型,旨在为寒区无砟轨道支承层设计与施工提供参考。Freeze-thaw cycles are one of the main factors that contributing to the deterioration of the service performance of the supporting layer concrete in ballastless track systems in cold regions.In this study,four different concrete mixtures with varying compressive strengths and air contents were prepared.The air content,pore structure characteristics,and compressive strength of the concrete were analyzed.The effects of air content on the compressive strength,mass loss,and relative dynamic elastic modulus of the supporting layer concrete through freeze-thaw cycles were investigated.The results show that the compressive strength and air content are key parameters affecting the frost resistance of ballastless track supporting layer concrete.Increasing the compressive strength and air content significantly improves the frost resistance of the supporting layer.Furthermore,the bubble spacing coefficient of hardened concrete was found to correlate well with the frost resistance of the supporting layer,making it a useful indicator for evaluating the frost resistance of low-strength supporting layer concrete.Based on the evolution of the mechanical properties of concrete after freeze-thaw cycles,a prediction model for freeze-thaw damage of supporting layer concrete was developed.This model aims to provide guidance for the design and construction of ballastless track supporting layers in cold regions.

关 键 词：支承层 低强度混凝土 含气量 抗冻性能 评价指标 预测模型 

分 类 号：U214.18[交通运输工程—道路与铁道工程]