Degradation of mechanical properties of CA mortar caused by calcium leaching
Degradation of mechanical properties of CA mortar caused by calcium leaching
复制标题
钙浸出导致CA砂浆力学性能下降
DOI：
10.1016/j.conbuildmat.2019.02.164
复制
发表时间：
2019-05-30
影响因子：
7.4
通讯作者：
Deng, Dehua
中科院分区：
文献类型：
--
作者：
Wang, Yong;Yuan, Qiang;Deng, Dehua
钙渗漏是无碴板式轨道用水泥沥青(CA)砂浆的重要耐久性问题。本文研究了用6mol/L硝酸铵溶液浸泡CA砂浆加速钙的浸出。研究了CA砂浆的浸出动力学及其力学性能和微观结构的变化。结果表明，钙的浸出符合Fick定律。钙的浸出导致在试件半径方向形成三个不同的钙含量区域。由于氢氧化钙的淋溶和C S H的逐步脱钙，三个带的化学成分不同。压缩力学行为用基于威布尔分布的压缩损伤模型来描述。建立了基于局部弹性模量分布的退化损伤模型。这两个模型的结合可以很好地预测部分淋溶CA砂浆的抗压性能。(C)2019爱思唯尔有限公司。保留所有权利。
Calcium leaching is an important durability problem for cement asphalt (CA) mortar used in ballastless slab track. In this paper, calcium leaching in CA mortar was accelerated by immersing in 6 mol/L ammonium nitrate solution. The leaching kinetics and related changes in mechanical behavior and microstructure of CA mortar were studied. Results showed that calcium leaching followed the Fick's law. The calcium leaching led to the formation of three distinct zones in term of local calcium content in the direction of radius of the specimen. Due to the leaching of calcium hydroxide and the progressive decalcification of C S H, the three zones had different chemical compositions. The compressive mechanical behavior was modeled by a compression damage model derived from Weibull distribution. The degradation damage model was established on the distribution of local elastic modulus. The combination of these two models can well predict the compressive behavior of partially leached CA mortar. (C) 2019 Elsevier Ltd. All rights reserved.