再生粗骨料混凝土及其构件抗冻性能研究进展

由于再生粗骨料中存在较多微孔隙和微裂缝,导致再生混凝土吸水率高且极易达到冻融破坏的临界水饱和程度,所以再生混凝土抗冻性能较差,严重危害了严寒地区混凝土建筑物的安全性和耐久性.因此,开展再生混凝土抗冻性能的研究对其在严寒地区的应用推广具有重要意义.基于再生混凝土冻融破坏的国内外研究现状,介绍了混凝土冻融破坏机理,综述了再...

Review on frost resistance property of recycled coarse aggregate concrete and its structural components

For severe cold areas, due to more micro-pores and micro-cracks in the recycled coarse aggregate (RCA), the high water absorption rate of recycled aggregate concrete (RAC) can easily reach the critical water saturation level of freezing-thawing damage, resulting in the poor performance in frost resistance, and seriously endanger the safety and durability of concrete buildings. Therefore, the research on frost resistance of RAC is of great significance to its engineering application. Based on the progress of research about the freezing-thawing damage of RAC at home and abroad, the deterioration mechanism of concrete was first introduced. Then, the influences of several factors including the quality and dosages of recycled coarse aggregates, water saturation degree, pore structure and the mineral admixtures on the frost resistance property of RAC were reviewed. Furthermore, the studies on the frost resistance of RAC members were summarized. The technical measures to improve the frost resistance of RAC were further discussed. Finally, the existing prediction models of freezing-thawing damage for RAC were summarized. Aiming at promoting the practical engineering application of recycled concrete in cold regions, the research on the frost resistance of RAC should be based on its actual service environment to reveal its influence on the macroscopic freezing-thawing damage mechanism from meso and micro level, and analyze the correlation mechanism between the meso- and micro-scale and the macro-scale.