水性环氧树脂改性水泥基快速修补砂浆的性能研究

Performance of Waterborne Epoxy Resin Modified Cement Based Rapid Repair Mortar

针对水泥混凝土路面早期出现的浅层病害对修补材料高早强及高耐久性需求,利用水性环氧树脂、自制特种胶凝材料和外加剂等进行复合设计,制备出2h抗压和抗折强度分别达到20.0 MPa、4.5 MPa以上,且后期强度不降低的快速修补砂浆,并研究了水性环氧树脂掺量对其力学、收缩和耐磨等性能的影响,在此基础上采用SEM分析了其微观性能。结果表明,在一定范围内提高水性环氧树脂掺量可使砂浆早期抗压、抗折强度降低,而粘结强度和28d抗折强度则明显增大;掺加水性环氧树脂可显著降低砂浆收缩并缩短收缩稳定期,对砂浆的抗硫酸盐侵蚀性能和耐磨性能有改善作用。SEM结果显示,修补砂浆2h即有大量的水化产物生成,引入适量水性环氧树脂可改善其微观结构。

Rapid repair mortar was designed by combining use of waterborne epoxy resin,self-made cementitious materials and admixtures to address the diseases of shallow pavement and meet the requirements of high early strength and high durability of repair materials.A kind of rapid repair mortar had a compressive strength of 20.0 MPa and flexural strength of 4.5 MPa after 2 hof paving.The influence of waterborne epoxy resin content on mechanical properties,shrinkage,and wear resistance of rapid repair mortar was investigated.Besides,the micro-structures were analyzed by SEM.Results indicate that,waterborne epoxy resin reduced the early compressive strength and flexural strength of mortar in a certain range of content,while the bond strength and 28 dflexural strength increased obviously.The shrinkage performance of the mortar was significantly reduced and the shrinkage stable period was shortened by adding waterborne epoxy resin.At the same time,it improved the sulfate resistance and wears resistance of the mortar.SEM results showed that there are a lot of hydration products in the repair mortar after 2 h,and the microstructure can be improved by introducing an appropriate amount of waterborne epoxy resin.