Application Of Polymer Modified Cement Concrete/Mortar In Anticorrosion And Repair Of Marine Engineering

Because reinforced concrete structures in ocean engineering are eroded and corroded by sea water for a long time,they will cause serious structural damage,but the anticorrosion and repair measures commonly used at present have not achieved the anticipated effect of long-term saving.Polymer modified cement concrete/mortar is a new type of building material in recent years,which usually has excellent waterproof and durability.After consulting a lot of literature,epoxy resin,epoxy resin emulsion and polyacrylate emulsion were selected as cement modified concrete / mortar modified polymers and their main properties were studied.Among them,the design strength of polymer modified cement concrete is C40,the epoxy resin and epoxy resin emulsion content is 0 to 20%,the design strength of polymer modified cement mortar is M30,the content of epoxy resin emulsion and polyacrylate emulsion is 0 ~ 20% and 0 ~ 35%,respectively,and the change rule of workability,mechanical strength and durability of cement concrete is analyzed and compared.The modification mechanism of polymer on cement concrete was analyzed by means of micro-characterization.In the study,the anticorrosion and repair technical scheme and construction technology are also put forward for the structural parts and damage degree of reinforced concrete structures in ocean engineering.The main conclusions are as follows:1)Epoxy resin has little influence on the workability of polymer modified cement concrete,and makes its mechanical strength increase and then decrease.The degree of durability improvement tends to change quickly and slowly with the content of epoxy resin.When the content of epoxy resin is more than or equal to 5%,its mechanical and durability indexes meet the requirements of anticorrosion and repair indexes of marine engineering concrete.2)Epoxy resin emulsion and polyacrylate emulsion all reduce the compressive strength of polymer modified cement mortar to a certain extent,but it can significantly improve its volume stability and durability.Experimental studies have shown that the best volume of epoxy emulsion and polyacrylate emulsion ranges from 15% to 20% and 20% to 25%,but the epoxy resin emulsion modified cement mortar resists pressure in this range.The degree is lower than the strength index of concrete repair mortar,and the economy is poor.3)According to the corrosion characteristics of reinforced concrete structures in different marine environment zones and marine engineering,the application technology of multi-layer system of anti-corrosion and repair is put forward.For example,in the areas where splashing zone and water level fluctuate,the areas with the most serious corrosion of reinforced concrete structures are epoxy resin modified cement concrete pouring+polyacrylate emulsion modified cement mortar protective layer+silane impregnating agent spraying.The results showed that epoxy modified cement concrete and polyacrylate emulsion modified cement mortar were used as anticorrosive and repair materials for marine engineering reinforced concrete structures.It has excellent mechanical properties,dry shrinkage and durability,and meets the requirements of the indicators.It is firmly bonded with the old concrete.It has good repair effect and remarkable social and economic benefits.