抄録
Influences of water/cement ratio, type and moisture content of artificial lightweight aggregate on deterioration of lightweight concrete due to freezing and thawing cycles were experimentally studied by measuring strain changes in specimens.
As a result, at the early cycle lightweight concrete contracted more than thermal strain through the freezing stage and expanded during the phases of thawing. At the lowest temperature, the specimen using lightweight aggregate containing large amount of water content contracted more than the other specimen. When expansion instead of contraction occurred on freezing, the rate of residual strain per cycle increased and then quickly destroyed after several cycles.
The increase in contraction strain suggests that not only the gel water but also moisture in lightweight aggregate has been transferred to mortar by freezing of water in the aggregate. When there is no spaces where the water can diffuse, high hydraulic pressure is occurring in the capillaries near at zero degree during freezing.
