Special topics in the freeze-thaw resistance of lightweight concretes

摘要

Durability of lightweight aggregate concrete is tested in terms of freeze-thaw testing according to EN 12371 up to 150 freeze-thaw cycles. Open pore lightweight aggregates (expanded clay and expanded glass) and closed pore lightweight aggregate (expanded glass) have been used for the comparison of normal weight concretes. It was revealed that the tendency and magnitude of deterioration for the high strength, open pore expanded clay aggregates is similar to that of the normal weight aggregates. The very light, low strength, open pore lightweight aggregates (both expanded clay and expanded glass) showed special behaviour; the minimum strength does not correspond to the maximum freeze-thaw cycle that needs further experimental studies for a more complete understanding. The closed pore expanded glass aggregates show slight increase in compressive strength up to 25-50 cycles, however, 100-150 cycles result complete failure, a more serious deterioration than found for the other types of lightweight aggregates. The results confirm the need of further detailed experimental studies in the topic.