Comparison of Two Freeze-Thaw Apparatus

About the report:

The purpose of this study was to compare the results of rapid freezing and thawing tests conducted on machine A with results from machine B, which is intended to replace the aging machine A. Concrete samples were prepared to attain levels of resistance to cycles of freezing and thawing. For comparison purposes, tests were conducted using the Research Council's procedure that is a modified version of ASTM C666 Procedure A. The modifications are the addition of one week of air drying following the two week moist cure and testing the specimens in a 2% NaCl solution rather than water. Also in machine B, because of its large size, some specimens were tested using the standard ASTM C666 Procedure A. The results indicate that both machines satisfactorily determine the relative freeze-thaw durabilities of concretes and that the data from one machine Can be related to the data from the other. In addition, the study showed that the use of salt in test water enables the differentiation of concretes resistant to severe environments from those resistant to moderate conditions. Also, modifications to the present acceptance criteria are given to differentiate between the moderate and severe exposure conditions.

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