Research On Physical And Mechanical Properties Of Hard Shell Pumice And Concrete Hollow Block

Make the best of rich lightweight aggregates resources all over the country, the development new type wall material with local characteristic, it means a great deal to social and economic benefits for energy shortage in our country. Pumice is a type of natural rock from volcano, reserves giant in our country. The paper is based on a series of research on physical and mechanical properties of hard shell pumice aggregate and a new type lightweight hollow concrete block.Curing the pumice aggregates coated with mortar, to form semisynthetic lightweight aggregates(hard shell pumice), then mix concrete. With the hard shell, pumice's water absorption rate reduce because of the changing irregularly porous structure state and the applying limitation of pumice concrete.The performance test of hard shell pumice and concrete indicated that, the physical and mechanical properties of hard shell pumice improved steadily. While in the process of mixing, cement usage, density, thermal conductivity reduced, workability and the ability of soundproof become better. Because the ingredients, mixing and pouring of hard shell pumice lightweight concrete is different to general ones. The paper also do tests on the preparation, mixing proportion, compressive strength and the thermal properties of hard shell pumice lightweight concrete. Hard shell pumice concrete product can achieve higher strength compared with general pumice in equal mixing proportion. In addition do some research on the influence of concrete additives to the properties of hard shell pumice lightweight concrete. Finally do tests on the shape, preparation, physical and mechanical properties of hard shell pumice concrete hollow block, results shows the block can be characterized by higher strength, construct easily and good energy-saving, according with GB15229-1994, this product can be generalized as a substitute for fire-clay brick in north China.