Alternative salt frost scaling test procedure for exposure class XF2

Abstract

Concrete structures in cold and moderate climates are often exposed to a combined salt frost attack, which can cause scaling damage. Consequently, numerous test procedures were developed to determine the resistance of concrete compositions against this kind of attack. These tests mimic a severe attack with high levels of saturation, which is typical for horizontal concrete elements or structures, such as concrete pavements. Very few approaches exist for testing the salt frost scaling resistance of concretes for vertical concrete elements like bridge columns, which are subjected to only moderate levels of saturation during salt frost attack (exposure class XF2). As such elements usually didn’t show notable scaling damage in practice, this hasn’t posed a problem until recently. However, the increasing use of low carbon cements with high clinker substitution rates might increase the vulnerability against salt frost exposure for such concrete elements to some extent. To ensure adequate durability it is desirable to determine the performance of the concrete in an actual test procedure instead of relying on descriptive criteria alone. Thus, a less severe test method was developed, which is based on the CDF test. It was shown that the modified test procedure can distinguish correctly between different concrete qualities. Furthermore, the applicability of an acceptance criterion for the method was investigated.