再生骨料混凝土耐久性能影响因素研究

简单破碎再生骨料混凝土的需水量很大,导致混凝土的收缩大、氯离子渗透系数大、碳化速度快以及抗冻性差等弱点.骨料颗粒整形技术可以除去骨料表面粘附的水泥石,减少表面微裂缝使得再生骨料变得圆滑,显著降低需水量,混凝土的收缩性能、抗氯离子渗透性、抗碳化性能和抗冻性能均显著改善,改善了再生骨料混凝土的耐久性能.

Influence Factors of Durability of the Recycled Aggregate Concrete

Compared with natural aggregate, simply-crushed recycled aggregate particles are attached by many hardened cement mortar remains on its surface, and micro-cracks are formed in the crushing process. Therefore, simply-crushed recycled aggregate concrete re-quests greater water demand which in turn leads to larger shrinkage, greater chloride ion permeability coefficient, quicker carbonization and lower freezing-thawing resistance. Nevertheless, particle reshaping is able to remove the adherent mortar and makes aggregate par-ticle smoother and stronger. The paper presents experimental researches on recycled concrete durability influences by particle-shaping. The results indicate that it reduces the water demand and the corresponding shrinkage, and herein improves the resistance to chloride ion permeability, carbonization property and freezing-thawing resistance. Consequently, the application domain of recycled concrete will be developed.