Title: Chloride Ion Penetration in Conventional Concrete and Concrete Containing Condensed Silica Fume

Author(s): Stella L. Marusin

Publication: Symposium Paper

Volume: 91

Issue:

Appears on pages(s): 1119-1134

Keywords: chlorides; concretes; cubes; penetration; portland cements; silica; tests; weight measurement.

DOI: 10.14359/10115

Date: 2/1/1986

Abstract:
The purpose of this work was to determine the chloride ion content distribution profile through l0-cm concrete cubes made from conventional portland cement concrete and concretes containing condensed silica fume. The conventional portland cement concrete and four concretes containing condensed silica fume were prepared and tested using a test procedure developed at Wiss, Janney, Elstner Associates, Inc. (WJE). The chloride ion penetration characteristics were studied on l0-cm concrete cubes, which were immersed in 15 percent NaCl solution for 21 days. Following the 21-day soaking period and a subsequent 21-day air-drying period, concrete powder samples were removed by drilling at depth intervals of 0 to 12 mm, 12 to 25 mm, 25 to 37 mm and 37 to 50 mm, and tested for acid-soluble chloride ion content using a potentiometric titration procedure. The test results showed that weight gain and chloride ion penetration are both reduced by concretes containing condensed silica fume. The best performance for both reductions, at all tested depths, was shown by concrete containing 10 percent of condensed silica fume. The chloride ion content at a depth of 12 to 25 mm reached the acid-soluble corrosion threshold level of about 0.03 percent by weight of concrete (as normally assumed for reinforced concrete) and was lower than this criterion below the depth of 25 mm.