Freeze–Thaw Resistance of Lightweight Concrete and Aggregate at Different Freezing Rates

Abstract

In this study, freezing and thawing tests were conducted on lightweight concrete and aggregate at different freezing rates (one cycle per day and six cycles per day) in order to investigate their freeze–thaw resistance and clarify the effects of various lightweight aggregate properties (density, water content, crushing strength, and pore structure) and freezing rates on their freeze–thaw resistance. The results indicate a high and direct correlation between the freeze–thaw resistance of lightweight concrete and aggregate. The higher density lightweight aggregate concrete showed superior freeze–thaw resistance at each freezing rate, while concrete made with the lower density aggregate achieved freeze–thaw resistance only at the low freezing rate. The aggregate tests showed similar results, too. The freeze–thaw resistance can be influenced by the properties of lightweight aggregate and the freezing rate, but the most fundamental factor is the pore structure of the aggregate. Lightweight aggregate, which has lower pore volume and more small pores, can have good resistance to freezing and thawing.