Experimental Study On Underwater Anti-dispersion Concrete

Due to the continuous development of human society and an increasing number of sea projects and underwater engineering, more attention is paid to the underwater concrete engineering. Ordinary concrete pouring underwater prone to the phenomenon of segregation and exudation, intensity is low too.Underwater concrete that anti-dispersion can overcome the shortcomings of normal concrete pouring in the water because of the agent resist concrete segregation.This paper introduces the development history and research status of underwater concrete that anti-dispersion firstly and the test method of it is presented, and then using the single factor rotation test to research the flow resistance, dispersion and cube compressive strength of underwater concrete that anti-dispersion on different conditions of the resistance of concrete to dispersing agent, the amount of fly ash and water-binder ratio, finally,we can find the underwater concrete that anti-dispersion,the amount of fly ash and water-binder ratio more reasonable. Main conclusions are as follows:Underwater concrete that anti-dispersion in certain dosage can significantly improve the strength of the underwater concrete and guarantee the concrete without segregation and exudation when pouring in the water, but it has certain influence on the liquidity of concrete, and it will decrease as the dosage of underwater concrete that anti-dispersion increase. The dosage of3%of the agent resist concrete segregation is reasonable.The water-cement ratio of concrete is an important factor affecting the mobility and strength of underwater concrete that anti-dispersion. The larger the water-cement ratio of concrete, the higher the fluidity of concrete underwater and the lower the strength is. Underwater concrete strength reached maximum when water-binder ratio get0.46, however,when lower than0.46its strength will reduce along with the depression of the water-cement ratio instead.Fly ash can enhance the liquidity of underwater concrete that anti-dispersion and cut down the gradual loss of the liquidity of concrete. Fly ash also can improve the late concrete strength of underwater concrete that anti-dispersion, the effect of fly ash is the most obvious between20%and30%.