相变混凝土抗冻性研究现状及发展方向

Research Status and Development Trend of Frost Resistance of Phase Change Concrete

混凝土的抗冻性是混凝土耐久性评价的关键指标,外部环境正负温循环影响和混凝土饱水度变化所引发的冰胀应力和静水应力将会使混凝土结构产生内外裂缝,降低混凝土的强度和刚度,损伤混凝土结构的整体性、稳定性和耐久性,甚至诱发贯穿性裂缝,直至破坏。利用相变材料在相变过程中释放潜热补偿缓解混凝土内部孔隙水冻结,从而达到改善混凝土抗冻性的目的,对延长混凝土结构的服役寿命有重要意义。本文总结分析了国内外利用相变材料改善混凝土抗冻性的研究进展,提出了目前研究中亟待解决的问题与相变混凝土未来研究的发展方向。

The frost resistance of concrete in cold regions is a key indicator for evaluating the durability of concrete.The ice swelling stress and static water stress caused by the positive and negative temperature cycles in the external environment and changes in concrete saturation will cause internal and external cracks in the concrete structure,reduce the strength and stiffness of the concrete,damage the overall integrity,stability and durability of the structure,and even induce penetrating cracks until failure.The use of phase change materials to release latent heat compensation during the phase change process to alleviate the freezing of internal pore water in concrete,thereby improving the frost resistance of concrete in cold regions,will be of great significance for extending the service life of concrete structures.This article summarizes and analyzes the research progress on using phase change materials to improve the frost resistance of concrete at home and abroad,and proposes the urgent problems in current research and the future research directions of phase change concrete.