机制砂及其胶砂性能试验研究

Study on Properties of Manufactured Sand Its Mortar

随着天然砂的日益短缺,机制砂成为解决混凝土细骨料短缺问题的途径之一。文章选取4个批次机制砂,测试了其物理性能指标,分析了不同机制砂的胶砂性能差异,进行了胶砂流动度、强度及收缩性能试验,结果表明:①MB值是影响机制砂胶砂流动度的主要因素,不同机制砂砂粉微观形貌差异较大,MB值较高的机制砂粉体颗粒表面较粗糙;②不同机制砂胶砂强度差异较大,强度差异原因仍需试验分析;③减缩剂可降低机制砂胶砂试件的收缩率值,减缩剂掺量1%、2%时,胶砂试件56 d收缩率值分别降低约30%和40%。

With the shortage of natural sand,manufactured sand has become one of the ways to solve the shortage of concrete fine aggregate.In this paper,four batches of manufactured sand are selected,their physical properties are tested,the differences of the properties of different manufactured sand are analyzed,and the fluidity,strength and shrinkage of the mortars are tested.The results show that:①MB value is the main factor that affects the fluidity of mortar,the micro-morphology of different manufactured sand powder is different,and the surface of manufactured sand powder with higher MB value is coarser;②The strength of mortar made by different manufactured sand has great difference,and the reason of the difference still needs to be analyzed by experiment;③Shrinkage reducing agent can reduce the shrinkage value of mortar made by manufactured sand.When the dosage of shrinkage reducing agent is 1%and 2%,the shrinkage value of mortar specimens decreases about 30%and 40%respectively at 56 days.