Characteristics of self-compacting concrete in fresh state with artificial light-weight aggregate

摘要

Recently, a new type of artificial light-weight aggregate has been developed. This aggregate has lower water absorption ratio than ordinary light-weight aggregate because of its tight surface structure, and can be used for concrete mixing without prewetting procedure. Another advantage of this aggregate is its spherical shape that is expected to increase the fluidity of concrete. In this study, this new light-weight aggregate was applied to self-compacting concrete, and the self-campactability of this concrete was investigated and discussed. The results show that self-compacting concrete with this aggregate has higher self-compactability than that with crushed stone, while the deformation rate of concrete is very small. Segregation between the aggregate and mortar, however, tends to be large because of larger difference of specific gravity between them than in the case of ordinary self-compacting concrete with crushed stone. Increase of unit mass of the light-weight aggregate does not affect so much on self-compactability of concrete. Also, a drop of self-compactability of self-compacting concrete with the light-weight aggregate with the lapse of time after mixing is less than that with crushed stone.