FROST DAMAGE MECHANISM AND PORE STRUCTURE OF CONCRETE

摘要

This study aims to clarify the frost damage mechanism of mortar. In this paper, features of the freeze-thaw phenomenon are obtained by experimental studies, which are the measurements of strain change and pore-size distribution under freezing-thawing conditions. From the experimental results, it has been clarified that these is an increase in the micro-pores (d=1.0~0.1μm) of the specimens subjected to freezing-thawing cycles. It is estimated that water in the pores under 0.05μm diameter does not freeze at -20℃. Calculation of the ratio of frozen water were made. These calculation results can well explain the behavior of frost damage.