Frost testing of HP/HVFA concrete for severe offshore conditions

Abstract

In the Durable Advanced Concrete Solution (DACS) project lead by Kvaerner and supported by a group of Norwegian concrete industries and The Norwegian Research Council the production and documentation of frost durable concrete for arctic and subarctic marine conditions is studied. The area encompasses frost exposure conditions and national standards relevant for the Arctic region. A series of HP/HVFA concretes were therefore subjected to various severe freeze-thaw tests of degradation due to internal cracking and surface scaling. Two of the most used methods, ASTM C666, procedure A for rapid freeze-thaw in water and CEN/TS 12390 for surface scaling in presence of 3 % NaCl solution, were used and extended to investigate how cracking, scaling and saturation progress at standard (-20 C) and very low (-50 C) temperatures in such severe conditions. This paper presents some preliminary results made to proceed in the understanding of how internal frost damage and surface scaling occur in rapid freeze-thaw testing in water (by far the most common way of frost testing concrete), how this relates to water uptake during curing and during subsequent freeze-thaw and the effect of air entrainment in this kind of frost testing. Keywords: Frost resistance, Fly ash, Air voids, Arctic Exposure, Freshwater scaling