Application of Expansion Agent in Crack Control of Immersed Tube Concrete
The effect of magnesium expansion agent,calcareous expansion agent and calcium magnesium compound expansion agent on shrinkage compensation of immersed tube concrete was studied.The crack control effect of different components of expansion agent was analyzed by crack observation.The results show that the shrinkage compensation effect of calcium magnesium complex expansion agent at early age of 2~3 d is the most obvious,and the central microstrain compensation value is up to 288.The expansion agent can effectively reduce the cracking risk of immersed tube concrete,the actual crack number is reduced by more than 40%,and the average crack width is reduced by 39%.