Paper by ?AHIN GÜL TA?DEMIR ÇELIK from ISCR 9th 2004 Instanbul Turkey
The main difference between pavements and other elements made of concrete is the surface property. The surface in concrete pavement must be finished properly. It has been known for a long time that air-entrainment can be used against freezing and thawing deterioration of concrete pavement slabs. In the freeze-thaw attack, most severe conditions are; i) horizontal concrete surfaces exposed to rain and freezing, and ii) roads and bridge decks exposed to de-icing agents. The main objective of this work is to investigate combined effects of finishing procedure and air-entrainment on the freeze-thaw scaling of horizontal concrete surfaces exposed to de-icing salt. For this purpose, at the experimental stage a total number of 50 cycles were applied. The parameters studied in this work were; watercement ratio, cement content, curing condition, the air-entraining admixture, and second finishing treatment. The experiments were conducted in accordance with ASTM C 672 and RILEM CDF. The parameters studied were optimized using Taguchi Optimization Method (L27). It has been shown that the use of de-icing salt on concrete surface causes progressive deterioration starting from the surface into the inner section. There is a significant effect of air-entrainment on the freeze-thaw scaling of horizontal concrete surfaces. It can be concluded that the second finishing treatment has a positive effect on first cycles but this effect diminishes its effect on the proceeding cycles.