陶粒预湿程度对轻骨料混凝土自收缩的影响

Effect of ceramsite prewetting degree on autogenous shrinkage of lightweight aggregate concrete

采用U型管微压测定装置测定不同预湿程度陶粒在陶粒混凝土中的吸水返水过程,用氮气吸附法测试陶粒混凝土中水泥石孔径分布情况,用测湿仪器监测陶粒混凝土内部湿度,用架立千分表的方法测试陶粒混凝土的自收缩.研究结果表明,随着陶粒预湿程度的提高,陶粒在陶粒混凝土中的吸水能力下降,返水能力提高,陶粒混凝土内部湿度下降幅度减小,陶粒混凝土产生的自收缩也减小.

The water absorption and desorption process of different prewetting degree ceramsites embeded in ceramsite concrete was obtained by an U-shape tube micro pressure measurement device.The pore size distribution of hardened cement paste in ceramsite concrete was tested by a nitrogen adsorption method.The ceramsite concrete internal humidity was monitored by adopting a humidity measurement instrument.The autogenous shrinkage of ceramsite concrete was also tested by using an erecting dial indicator method.The study reveals that for the ceramsites embeded in ceramsite concrete,with the increase of ceramsite prewetting degree,the ability of water absorption declines and the ability of water desorption increases,and the internal humidity of ceramsite concretes declines,and the autogenous shrinkage of ceramsite concretes also decreases.