Research On The Strength And Volume Stabitily Of Internl Curing Concrete

Along with social progress and the growing shortage of natural resources, durability of concrete has aroused extensive attention. However, the continuous advances of modern concrete technology lead to finer and finer cement and lower and lower water-cement ratio. These technology results in large amounts of original concrete defects, which directly affect the durability of concrete, the most obvious one of which is the autogenous shrinkage of concrete.Super Absorbent Polymer (SAP) has a strong absorption and water-retention capacity. Being processed into the SAP powder with one dispersant(ICSAP, internal curing agent of concrete) to a certain size and added to the concrete, ICSAP can be used as good concrete curing agent to converse the concrete insides, increase the internal humidity, reduce the shrinkage resulting from internal humidity and then reduce the defects of concrete itself and improve the durability of concrete.Through a large number of experiments, this paper does a deep research on the regular pattern of how intermingled quantity and additional amount of water influence the strength and volume stability of concrete, how internal curing agent of ICSAP affects concrete of different cementitious materials and how internal curing agent of ICSAP affects the strength of concrete under different environmental conditions. And this thesis also presents readers the exploration and analysis of mechanism to increase the strength, reduce the autogenous shrinkage and improve volume stability of concrete by means of micro tools including SEM (Scanning Electron Microscope) and DTA/TG thermo gravimetric differential thermal analysis.Through the research above, the paper conclude that the incorporation of ICSAP can slightly increase the strength, significantly reduce the autogenous shrinkage of concrete and improve the volume stability of concrete. And the analysis of the whole tests shows that the best content of ICSAP is between 0.15% and 0.2% and the will relatively decreases as the content of SAP increases. When the content of SAP is 0.15%, the best additional amount of water is 15 to 25 times as much as the quantity of ICSAP. Study of varieties of micro tests demonstrates that ICSAP can promote hydration of cementitious materials significantly, increase the hydration degree of binder and the density of concrete and then enhance the durability of concrete, which will play a good effect within the inernal curing.