硫酸盐侵蚀后水泥砂浆力学性能变化

Study on mechanical properties of the mortar corraded by sulfate

通过进行对不同水灰比、不同硫酸盐侵蚀时期的砂浆进行单轴压缩试验,获得其应力应变全过程的关系曲线。试验结果表明:随侵蚀的进行,砂浆的峰值应力经历一个先增大后降低的过程,强度增大过程随水灰比而变化,水灰比越大,增大期越早。在试验的基础上,利用分段曲线损伤模型对砂浆单轴受压损伤演化进行了描述,该模型能反映砂浆单轴损伤演化规律,所拟合的损伤演化曲线符合砂浆损伤的两阶段特点。

Uniaxial compression tests on the mortar of different water-cement ratio and sulfate corrosion were carried out to obtain the entire stress-strain curves. Test results show that the peak stress firstly increases and then decreases with the increase of sulfate corrosion. The processes of strength increase are different with different water-cement ratios. The greater the water-cement ratio is, the earlier the increase appears. Based on the tests, a subsection curve damage model is applied to describe the damage evolution of the mortar and the parameters of the damage model are determined by the evolution curves from the uniaxial compression tests. It is shown that the subsection curve damage model can reflect the two damage stages of mortar.