再生混凝土的耐久性及其改善措施

Durability and improvement measure of recycled aggregate concrete

在大量文献研究的基础上,本文较为全面地综述和分析了再生混凝土的耐久特征及其改善措施,主要包括再生混凝土的抗渗性、抗冻融性、抗硫酸盐侵蚀性、碳化以及氯离子渗透性和耐磨性。研究表明,总体来讲,再生混凝土的耐久性较普通混凝土差。但是,通过减小水灰比、掺加粉煤灰、采用二次搅拌工艺、减小再生骨料最大粒径和采用半饱和状态的再生骨料等措施可以改善再生混凝土的耐久性。最后,提出了关于再生混凝土耐久性需要进一步研究的问题。

Based on the analysis of many related references,an extensive review on the durability of recycled aggregate concrete and improvement measure are given in this paper.The impermeability,the freeze and thaw resistallce,the sulphate and acid resistance,the carbonation resistance,the chloride penetration resisance as well as the abrasion are discussed in detail.It is shown that the durability of recycled aggregate concrete is generally lower than that of normal concrete.However,the poor durability of recycled aggregate concrete can be offset by lowing the water/cement ratio,the addition of fly ash,the double mixing method,the decreasing of the maximum size of recycled aggregate or the use of semi-saturated recycled aggregates.Finally,some recommendations on further studies on the dueability of recycled aggregate concrete are presented.