高原高海拔地区混凝土抗冻性能研究进展

Research progress on frost resistance of concrete in high plateau and High altitude areas

随着工程项目向西部地区的转移,对混凝土的抗冻性能有着更高的要求。在综述国内外混凝土冻融循环测试技术之后,从时间顺序总结了静水压理论、渗透压理论、结晶应力理论、微冰晶生长理论、不饱和孔隙弹性理论和带电多孔介质中电解质的冻结理论等六种普遍认可的冻融破坏机理。再从配合比、外掺剂、施工工艺三个方向对改善混凝土抗冻性能进行论述。最后,对混凝土抗冻性能进行了全面总结,为高原高海拔地区混凝土抗冻性能研究提供参考。

With the transfer of engineering projects to the western region,the frost resistance of concrete has higher requirements.This paper summarizes concrete's freeze—thaw cycle testing techniques at home and abroad.Secondly,it summarizes six generally accepted freeze—thaw damage mechanisms in chronological order,such as hydrostatic pressure theory,osmotic pressure theory,crystallization stress theory,micro—ice crystal growth theory,unsaturated pore elasticity theory,and the freezing theory of electrolytes in charged porous media.Then,the improvement of concrete frost resistance is discussed from three directions:proportion,external admixture,and construction process.Regarding admixtures,the most common improvement means are air—entraining agents,fiber reinforcement,nanoparticles,and superabsorbent resins.Finally,the antifreeze performance of concrete is comprehensively summarized,which provides a valuable reference for the research of antifreeze performance of concrete in high plateau and high altitude areas.