Abstract: In order to solve the problem that the cementitious materials are easy to expand when exposed to water and affect the strength in the in-situ repair process of solid waste landfill leakage. KH560 with amphoteric groups was added to sodium polyacrylate and electrolytic manganese slag by two-step aqueous solution polymerization method to prepare electrolytic manganese slag-based composite cementitious materials. The compressive impermeability and corrosion resistance of the consolidated body were analyzed by water seepage test and corrosion test,the molecular structure of the consolidated body was characterized by infrared spectroscopy (FTIR),and the surface morphology and element content changes of the consolidated body were analyzed by SEM-EDS,and the mechanical enhancement mechanism and anti-seepage mechanism of KH560 on the electrolytic manganese slag cementitious material were revealed. The results show that:① the compressive resistance,impermeability and corrosion resistance of the composite cementitious material can be significantly improved by adding KH560 in an appropriate amount 3%,and the unconfined compressive strength of the consolidated body is 2. 25 times that of the consolidated body without KH560,and the permeability coefficient is 61. 3% lower than that of the consolidated body without KH560,and the corrosion resistance coefficient is 0. 85. ② The siloxy group Si—OCH3 in the molecular structure of KH560 underwent a hydrolytic condensation reaction with the free water in the electrolytic manganese slag to form a Si—O—Si connection structure,which reduced the water gap channel,made the surface of the consolidated body smooth,and significantly improved the impermeability effect and corrosion resistance.

Key words: KH560,electrolytic manganese slag,compressive strength,permeability coefficient,mechanism of action