Key technologies of crack control for super-long as-cast-finish concrete wall structure
WANG Demin
LU Chuanming
WANG Linyi
SHEN Xiaowen
ZHANG Yiqi
LI Zhixiang
Abstract：The shrinkage-compensating concrete prepared by calcium and magnesium oxides based expansive agent had achieved good crack control effect of super-long as-cast-finish concrete wall structure,and the continuous pouring length of wall concrete on the ground and exterior facades of the project was nearly 70 m.The data analysis showed that the 14 d limited expan-sion rate of C40 crack-resistant concrete in water was 0.028 percentage point higher than that of C40 benchmark,and the 14 d in water to air 28 d value was 0.036 percentage point higher,indicating that the calcium and magnesium oxides based expansive agent had high micro-expansion performance in the early stage of concrete,and there was still a moderate amount of micro-expansion re-lease in the middle and late stages.The maximum value of early maximum micro-strain with temperature correction in fair-faced concrete was about 1～110 με,and slowly decreased to about-44 με～31 με within 30 d,indicating that the shrinkage deformation of solid junction structure was small and the risk of shrinkage cracking was low.
Keywords：as-cast-finish concretesuper-long wall structurecalcium and magnesium oxides based expansive agentshrinkage compensated concretecrack control
Publication Date：2025-07-25
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：4( 49-52 )