Impact of frost temperature and moisture content on frost damage to ceramic bricks

Abstract

Reliable knowledge on how frost deteriorates building materials is necessary when assessing the hygrothermal performances of building facades. Unfortunately, the current frost-thaw testing methods do not offer dependable knowledge, as they only test at very low temperatures and very high moisture contents, contrary to the spectrum of milder conditions usually met in reality. This paper therefore studies frost damage to four ceramic bricks, with accele-rated frost-thaw tests at frost temperatures from -2 °C to -20 °C and moisture saturation degrees from 0.1 to 1.0. The ultrasonic method is used to quantify the resulting frost damage, with the Young’s modulus reduction as index. The actual frost temperature and moisture content affect the level of frost damage, an effect which is not recognised however in current frost-thaw test protocols.