The complex compositions and large shrinkage of concrete,as well as the strong constraints of the structures,often lead to prominent shrinkage cracking problems in modem concrete structures.This paper first introduces...The complex compositions and large shrinkage of concrete,as well as the strong constraints of the structures,often lead to prominent shrinkage cracking problems in modem concrete structures.This paper first introduces a multi-field(hydro-thermo-hygro-constraint)coupling model with the hydration degree of cementitious materials as the basic state parameter to estimate the shrinkage cracking risk of hardening concrete under coupling effects.Second,three new key technologies are illustrated:temperature rise inhibition,full-stage shrinkage compensation,and shrinkage reduction technologies.These technologies can efficiently reduce the thermal,autogenous,and drying shrinkages of concrete.There after,a design process based on the theoretical model and key technologies is proposed to control thecracking risk index below the threshold value.Finally,two engineering application examples are provided that demonstrate that concrete shrinkage cracking can be significantly mitigated by adopting the proposed methods and technologies.展开更多
基金supported by the National Key R&D Program of China(2017YFB0310100)the National Basic Research Program of China(2015CB655105)the National Outstanding Youth Science Foundation Program(51225801).
文摘The complex compositions and large shrinkage of concrete,as well as the strong constraints of the structures,often lead to prominent shrinkage cracking problems in modem concrete structures.This paper first introduces a multi-field(hydro-thermo-hygro-constraint)coupling model with the hydration degree of cementitious materials as the basic state parameter to estimate the shrinkage cracking risk of hardening concrete under coupling effects.Second,three new key technologies are illustrated:temperature rise inhibition,full-stage shrinkage compensation,and shrinkage reduction technologies.These technologies can efficiently reduce the thermal,autogenous,and drying shrinkages of concrete.There after,a design process based on the theoretical model and key technologies is proposed to control thecracking risk index below the threshold value.Finally,two engineering application examples are provided that demonstrate that concrete shrinkage cracking can be significantly mitigated by adopting the proposed methods and technologies.
