Title: Durability of Concrete Structures Exposed to CaCl 2 Based Deicing Salts

Author(s): M. Collepardi, L. Coppola, and C. Pistolesi

Publication: Symposium Paper

Volume: 145

Issue:

Appears on pages(s): 107-120

Keywords: calcium chlorides; chlorides; corrosion; deicers; durability; salts; silica fume; slags; water-cement ratio; Materials Research

DOI: 10.14359/4543

Date: 5/1/1994

Abstract:
The authors indicate that, in addition to steel corrosion, calcium chloride can act specifically as an aggressive agent for concrete through the formation of calcium oxychloride (3CaO CaCl 2 15H 2O). This product is formed by reaction of CaCl 2 diffusing through the cover and Ca(OH) 2 produced by cement hydration. The main purpose of the paper was to study the influence of the cementitious system (portland cement with and without a pozzolanic addition) on the damaging effect caused by CaCl 2 used as a deicing agent. To block both steel corrosion and concrete deterioration, the reduction of the water-cement ratio in the concrete mix should be accompanied by the utilization of slag cement or pozzolanic cement. The slag content should be at least 50 percent of the cement, but silica fume (> 15 percent by weight of cement) instead of fly ash (30 percent) is preferred.