硫酸盐侵蚀环境中EVA砂浆的耐久性能研究

Study on durability of EVA mortar in sulfate attack environment

将标养28 d的EVA热熔胶胶砂试件、承受了30%极限弯曲荷载的标养试件(预损伤试件)及加热修复后的预损伤试件放进0、0.3%、3.0%、10%的硫酸钠溶液中浸泡,通过比较试件浸泡前后抗折强度和质量的变化衡量了热熔胶的修复性能并通过强度衰减理论建立了EVA水泥基材料关于热熔胶掺量及浸泡浓度的耐久性寿命预测模型。结果表明,修复后的预损伤试件的质量的变化比标养试件及未修复的预损伤试件小,抗折强度均比无损伤的标养试件高。通过水泥基材料寿命预测模型计算,经加热修复后的EVA预损伤试件在硫酸盐侵蚀环境中的寿命均超过200年。

Three types of specimens,including standard cured specimens containing EVA hot melt adhesive,pre-damaged specimens（standard cured specimens after subjecting to 30% ultimate bending strength）and pre-damaged specimens after healing by heat,were placed in 0,0.3%,3.0% and 0.3% sodium sulfate solution.Anti-sulfate attack performance of EVA specimens was evaluated by comparing the changes of quality and flexural strength of mortars before and after immersing.Based on strength attenuation theory,service life prediction model of EVA mortar in sulphate attack environment was established.Test results show that quality variation of pre-damaged specimens after healing is lower than that of intact standard cured specimens,while flexural strength of healed specimens is higher than of reference samples.Service lives of EVA pre-damaged specimens after healing in sulphate attack environment are all exceeded 200 years.