分类再生细骨料对建筑砂浆性能影响的试验研究

Classification recycled fine aggregate impact on the performance of building mortar experimental study

将不同来源的废弃混凝土破碎筛分后，按照《混凝土和砂浆用再生细骨料》分为Ⅰ、Ⅱ、Ⅲ类，依据《建筑砂浆基本性能试验方法标准》对这三类再生细骨料设计五种不同取代率的水泥砂浆标准试块，测定其和易性和抗压强度，并对取代率为100％的再生砂浆界面结合区的微观形貌进行观察。试验结果表明：Ⅰ、Ⅱ、Ⅲ类再生细骨料所配制的砂浆和易性和强度依次降低；控制稠度在60-90mm时，随取代率的增大，用水量增大，保水性降低，强度降低；通过SEM观察，Ⅱ类再生细骨料与水泥石黏结较好，强度也较高。建议Ⅰ类再生细骨料取代率不宜超过50％，Ⅱ、ⅢI类再生细骨料不宜超过30％。

After crushing and screening different sources of waste concrete,it divided them into Ⅰ、Ⅱ、Ⅲ, categories by the＂Recycled fine aggregate for concrete and mortar＂ .Then five different standard cement mortar test block of these three types recycled fine aggregate were designed according to five different replacement ratio, which was used to determine their workability and compressive strength by the ＂Standard for test method of performance on building mortar＂.The results showed that the workability and strength of Ⅰ、Ⅱ、Ⅲ class recy- cled fine aggregate mortar were decreasing;When controlling the consistency in the 60-90 mm,water consumption was increasing while water-retaining capacity and compressive strength was reducing with the replacement rate increasing; Class II fine aggregate and cement bond better by SEM observation,the intensity was higher.So it recommended that the replacement ratio of class Ⅰ recycled fine aggregate should not exceed 50% and Ⅱ、Ⅲclass recycled fine aggregate should not exceed 30%.