盐渍土腐蚀环境下微胶囊自修复混凝土抗腐蚀性能研究

Study on the corrosion resistance of microcapsules self-healingconcrete under corrosive environment of saline soil

为保证盐渍土地区混凝土服役寿命,区别于以往自修复材料,合成一种可以感知外界腐蚀离子并释放内部修复剂的微胶囊,以合成温度为变量控制引发剂分解速率得到了具有不同包裹率的微胶囊。选取其中包裹率、腐蚀离子响应能力较好的微胶囊,将其掺入混凝土中得到具有自修复功能的混凝土。改变微胶囊掺量测试混凝土动弹性模量及抗腐蚀能力。研究结果表明:在合成温度为75℃环境条件下的微胶囊包裹率优于65和85℃环境条件下。盐渍土-硫酸盐干湿循环腐蚀下混凝土构件动弹性模量均呈现先上升后下降的趋势,在20次干湿循环后未掺微胶囊的混凝土动弹性模量急速下降,在40次干湿循环后为掺微胶囊的混凝土内部侵入了更多的硫酸盐,试验拌制的自修复混凝土具有良好的抗硫酸盐侵蚀能力,对实际工程中建筑结构应对硫酸盐腐蚀具有十分重要的借鉴意义。

In order to ensure the service life of concrete in the saline soil area,different from the previous self-healing materials,a microcapsule that can sense external corrosion ions and release internal repair agents is synthesized,and the decomposition rate of the initiator is controlled by the synthesis temperature variable to obtain microcapsules with different parcel rates.The microcapsules with good wrapping rate and corrosion ion response ability were selected and incorporated into the concrete to obtain concrete with self-healing function.The amount of microcapsule doping was changed to test the dynamic elastic modulus and corrosion resistance of concrete.The results show that the microcapsule wrapping rate at an ambient temperature of 75℃is better than that of 65℃and 85℃.Under the corrosion of the dry and wet cycle of saline soil-sulfate,the modulus of concrete components showed a trend of first rising and then falling.The modulus of concrete without microcapsules dropped rapidly after 20 dry and wet cycles.More sulfates were invaded into the interior of the concrete mixed with microcapsules after 40 dry and wet cycles,and the self-repairing concrete mixed in this test has good resistance to sulfate erosion,which is of great reference significance for building structures to cope with sulfate corrosion in actual projects.