Title: Influence of Curing on Chloride Ions Penetration in Concretes

Author(s): A.R. Martins and G. Camarini

Publication: Symposium Paper

Volume: 207

Issue:

Appears on pages(s): 151-168

Keywords: blast furnace slag; chloride ions penetration; concrete; curing; durability; stream curing

DOI: 10.14359/12388

Date: 10/7/2002

Abstract:
Chloride ions penetration can be an important cause of concrete reinforcement depassivation and corrosion, especially in marine environment structures. The influence of ground granulated blast furnace slag replacement in portland cements on chloride ions penetration in cover concrete was investigated. Concretes with W/C of 0.42 and three different Portland cements, containing O%, 27% and 53% of blast furnace slag replacement by mass, were manufactured. The influence of two curing conditions on chloride ions absorption was also investigated: immersion inwater (25OC) for 7 days and steam curing (6O’C) for 2 hours. Concrete samples were submitted to 8 wetting-drying cycles in 5% NaCl solution. Water-soluble chloride ions concentration was monitored in all the 8 cycles, in the cover depth from 0 to 40mm. Concretes produced with slag cements have shown the lowest chloride ions content in both curing methods investigated. Considering 0.4% by cement mass as a maximum value of chloride ion content to prevent reinforcement depassivation, it was observed that blast furnace slag cement concretes have shown results under this limit from the depth of 1Omm when wet-cured and from the depth of 20mm when steam cured.