Abstract
This paper discribes the effects of the rate of cooling on three dimension changes of freezing and thawing mortars. Nine river sand mortars, three cement pastes and one standard sandmortar were used to laboratory freezing and thawing tests. The rate of cooling of freezing and thawing was prepared at six levels from 0.09℃/min to 0.41℃/min. The results obtained are summarized as follows, (1) Longitudinal length change of freezing and thawing river sand mortars was less the change of laternal dimension. (2) e_l/e_b ratio was affected by the rate of cooling, and the experimental formulae were obtained as follows, River sand mortars…e_l/e_b=0.31α+0.43 Cement pastes…e_l/e_b=9(α-0.22)^2+0.37 Standard sand mortars…e_l/e_b=[numerical formula] Where α : rate of ccoling (℃/min) (3) Frost damage of mortars was affected by the rate of cooling and three dimension changes, and the experimental formula was obtained.
