板式无碴轨道CA砂浆的配制和性能

Configuration and Performance of CA Mortar for Ballastless Slab Track

CA砂浆是板式无碴轨道结构弹性调整层的核心.对CA砂浆的拌和工艺、配合比的选取以及试验数据、技术参数之间的关系进行了系统对比和统计分析.通过多次试验,确定了水泥、乳化沥青、掺和材、细骨料、表面活性剂、减水剂和铝粉等材料的选取、投料顺序、搅拌速度、搅拌时间和配合比,配制的CA砂浆流动度好、可工作时间长、早期有膨胀、后期收缩小,性能满足板式轨道功能和施工现场需要.对CA砂浆拌制中的时间与密度及空气含量、静停时间与密度及空气含量、静停时间与流动度的关系进行了对比分析;对强度与水灰比、砂用量、乳化沥青用量,不同龄期抗压强度发展,不同尺寸试件之间抗压强度,用水量和乳化沥青用量与流动度,弹性模量与抗压强度关系等提供了规律性的结果.结果表明,CA砂浆的关键是配制乳化沥青,其掺和成分为聚乙烯醇、乳化剂,采用中裂乳化剂乳化的沥青配制的CA砂浆性能最稳定.

CA mortar is the most important component of flexible adjusting layer of ballastless slab track structure. The mixing technique, designed mixing ratio, and the relation between testing data and technical parameters of CA mortar were compared and analyzed statistically. After several tests, the choosing, feeding sequence, mixing speed, mixing time and mixing ratio of materials such as cement, emulsification asphalt, admixture, fine aggregate, surface activator, water reducing agent and aluminum were determined. And mixed CA mortar shows good fluidity and long workability, with expansion during early phase while small shrinkage during later phase to ensure its performance to the requirement of slab track function and actual construction demand. Furthermore, the paper analyzed the relations between diffeiential mixing time and density and air content, between initial curing time and density and air content, and belween initial curing time and fluidity. The regular results between strength and water-binding ratio, sand and emulsification asphalt consumption, compressive strength development during different ages and different dimension specimen, water consumption and emulsification asphalt consumption and fluidity, compressive strength and elastic modulus, etc. were provided. The results show that the key part of CA mortar is emulsification asphalt configuration, while polythene alcohol and emulsification agent are the main admixtures. CA mortar becomes the most stable mixed using the asphalt with medium-setting emulsification agent.