Journal Published Online: 01 June 1997
Volume 19, Issue 1

Frost Deicer Salt Scaling Testing of Concrete: Effect of Drying and Natural Weathering

CODEN: CCAGDP

Abstract

Laboratory deicer salt scaling of concrete is very sensitive to prior drying and resaturation, weathering, or aging. Previous investigations have shown both positive and negative effects. The object of this investigation was to quantify the effect of pre-conditioning on scaling test results and to provide data for the relationship between laboratory testing and field exposure. Four concretes with W/B = 0.45 and various binders and air void systems were subjected to a range of different pre-treatments. These included a variety of RH, temperature, and wind combinations that resulted in a variety of evaporation rates from free water surface. Other pre-treatments were no drying (virgin condition) and natural weathering for 3 months and 1 year in Québec City. Subsequent resaturation with water and scaling testing with 3% NaCl confirmed that mild drying gives lower scaling than both virgin condition and severe drying. Natural weathering resulted in scaling of the same magnitude as that of mild drying, indicating that the standard mild laboratory drying at 50% relative humidity and 20°C is suitable. The protective effect of the air voids is considered activated after mild drying, vanishes after more severe drying, and not affected by natural weathering. Water filling of air voids during wet curing can be the cause of the high scaling on virgin concrete. 5% silica fume reduced the effect of weathering and drying, and gave lower scaling than OPC concrete. Wet freeze/thaw gives high uptake of liquid compared to capillary absorption and therefore rather severe test conditions.

Author Information

Jacobsen, S
The Norwegian Building Research Institute, Oslo, Norway
Marchand, J
Laval University, Québec, Canada
Boisvert, L
Laval University, Québec, Canada
Pigeon, M
Laval University, Québec, Canada
Sellevold, EJ
The Norwegian University of Technology and Science, Trondheim, Norway
Pages: 9
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Stock #: CCA10015J
ISSN: 0149-6123
DOI: 10.1520/CCA10015J