混凝土内养护技术研究进展评述

Review of Research Progress on Concrete Internal Curing Technology

摘要:

高强混凝土水胶比低、渗透性差，外部养护水难以进入混凝土内部，造成传统外部养护效果变差，由此产生的自收缩会导致材料的开裂敏感性提高。通过在混凝土配合比中引入高吸水性材料实现内部养护是解决此问题的有效途径。综述了目前混凝土常用的内养护材料及其物理力学特征和用量；阐述了混凝土内养护理论基础、自收缩产生机理和内养护减缩机制；总结了不同内养护材料对减少混凝土收缩和影响力学性能的规律：一般来说，内养护可以减少自收缩，但对干燥收缩的影响与引入的额外水量有关，对混凝土强度和弹性模量则会产生不利影响；最后，提出了当前混凝土内养护技术研究存在的问题及未来可能的研究方向。

Abstract:

High strength concrete has low water-binder ratio and poor permeability, so it is difficult for external curing water to enter the interior zone of concrete, leading to the worse effect of traditional external curing, and faces the risk of cracking caused by autogenous shrinkage. It is an effective method to solve the problem by adding super absorbent material to concrete mix proportion to realize internal curing. The internal curing materials, physical and mechanical characteristics and dosage of concrete are reviewed. And the theoretical basis of concrete internal curing is explained. Furthermore, the mechanism of autogenous shrinkage and the mechanism of internal curing shrinkage reduction are discussed. In general, internal curing can reduce autogenous shrinkage, but the effect on drying shrinkage is related to the extra water. And it has a negative effect on the strength and elastic modulus of concrete. Finally, the existing problems and possible future research directions for the current internal curing technology of concrete are discussed.