The critical freeze-thaw cycle considering moisture content increase in the accelerated freeze-thaw test

Abstract

In the paper, specimens with 2 kinds of water to cement ratios were conducted with the accel- erated freeze-thaw test and the critical degree of saturation test. In the accelerated freeze-thaw test, the trend of the relative dynamic modulus of elasticity (RDM) can be divided into two parts. In the first part, RDM decreased slightly, while it dropped significantly in the next part. It is believed that with the con- duction of the freeze-thaw, the mass moisture content increases. Consequently, severe deterioration would occur when the critical mass moisture content is reached. The freeze-thaw cycle where RDM decreased significantly is defined as Nf. The mass moisture content (Wcr) at Nf is calculated and compared with that of the critical moisture degree (Scr). According to the results, Wcr almost equals to the mass moisture content of Scr. Besides, no clear relationship can be found out between the durability factor DF in the accelerated freeze-thaw test and Tpl calculated from the critical degree of saturation test. However, Nf is in good accordance with DF. The freeze-thaw function in the real environment can be converted into a portion of the new defined evaluation criterion Nf to evaluate the situation of the deterioration by the real environment.