Study On Properties And Mechanism Of Super Absorbent Polymer Modified Cement Mortar

For cement based composite material itself is a kind of porous material,prone to water seepage problem,so this topic from the "water seal" point of view,to find water swellable super absorbent polymer materials with good water absorption and water retention.The purpose of "water seal" is achieved by adding super absorbent polymer in cement mortar.In this study,the super absorbent polymer was mixed and added with a certain amount of added water to ensure the working performance of cement mortar,super absorbent polymer system research to the influence of cement mortar in all aspects.Through the research on the performance of super absorbent polymer modified cement mortar,it is found that due to the addition of the additional water by dry mixing,the consistency and fluidity of cement mortar increased with super absorbent polymer mixed with the increase of the amount,but the wet density and water retention rate decreased.At the same time,it also results in the decrease of the dry density of the super absorbent polymer modified cement mortar,but the water absorption increased.The mechanical properties of super absorbent polymer modified cement mortar were found to be lower than those of non-doped super absorbent polymer,and the mechanical strength decreased most obviously at the 3rd day.However,with the increase of curing time,the mechanical strength decreased in the range of reduced slowly and slowly compared with the blank group.Through the study of the durability of the super absorbent polymer modified cement mortar,it is found that the incorporation of the super absorbent polymer can obviously improve the early crack resistance of the cement mortar.At the same time,with the increase of super absorbent polymer admixture,cement mortar shrinkage decreased,the sulfate resistance and frost resistance gradually increased.And when the amount of super absorbent polymer is 0.5%,the impermeability of the super absorbent polymer modified cement mortar is the best.The non evaporable water and SEM analysis of super absorbent polymer modified cement mortar showed that non evaporation content of cement mortar increased gradually and ettringite and hydrated calcium silicate gel content is gradually increasing with the increase of the doping amount of super absorbent polymer.It can be seen that the super absorbent polymer can improve the degree of hydration of cement and make cement hydration more fully.