轻骨料吸水返水特性及其对轻骨料混凝土抗裂性能的影响

Effect of water absorption and desorption property of lightweight aggregates on the cracking resistant behavior of lightweight aggregate concrete

采用U型管微压测定装置测定页岩陶粒的吸水返水过程,采用带隔板环形约束收缩装置测定轻骨料混凝土的抗裂性能。研究表明:未预湿页岩陶粒在陶粒混凝土中的吸水返水过程分为3个阶段:吸水、吸水返水、返水。陶粒混凝土在龄期10d左右在隔板处突然出现贯通性裂缝,而普通混凝土内部微裂缝在龄期10d后逐渐发展;28d龄期时,陶粒混凝土的裂缝宽度比普通混凝土的大。

The water absorption and desorption process of shale ceramsite was obtained by a U-tube micro pressure measurement device.The cracking resistant behavior of lightweight aggregate concrete was evaluated by a ring restrained shrinkage equipment with a clapboard.The study reveals that the water absorption and desorption process of non-prewet shale ceramsite in ceramsite concrete includes three stages：water absorption,water absorption and desorption and water desorption;a crack throughout the whole section of ceramsite concrete was appeared at the age of approximate 10 days,while the micro-cracks of normal concrete developed gradually after 10 day curing;at the age of 28 days,the crack width of lightweight aggregate concrete was larger than that of normal concrete.