Title: Study on Corrosion Prevention in Reinforced Concrete Containing Condensed Silica Fume and its Application

Author(s): Lu Anq

Publication: Symposium Paper

Volume: 126

Issue:

Appears on pages(s): 499-510

Keywords: carbonation; chlorides; concretes; corrosion; durability; electrical resistance; permeability; reinforced concretes; silica fume; Materials Research

DOI: 10.14359/2286

Date: 8/1/1991

Abstract:
This paper addresses the effect of condensed silica fume on the factors controlling the two stages of corrosion of reinforced concrete. The corrosion-resisting capabilities of concretes with and without condensed silica fume were evaluated through impermeability, electrical resistivity, carbonation, chloride penetration, and soaking and stoving tests of reinforced concrete. In the case of concrete containing condensed silica fume, tests were carried out with various amounts of condensed silica fume. The test results show that concrete with condensed silica fume exhibits excellent corrosion resistance. A comparison between concrete containing condensed silica fume and conventional concrete for the same cement content shows the following: Use of condensed silica fume raises impermeability to 4 to 46 times and electrical resistivity to 2 to 9 times: the total charge passed decreases markedly after 6 hr of testing at 70 VDC; the silica fume concrete has a depth of carbonation of only 3.7 mm, while the conventional concrete has a depth of carbonation of 17.8 mm after 28 days of exposure to 20 percent carbon dioxide; and the concentration of chloride ions in the concrete surrounding the reinforcing bar is reduced 9 times after 22 soak-stove cycles in seawater. The durability of silica fume concrete in seawater is extended more than 2.2 times, as inferred from the time of initiation of corrosion. The paper gives a description of the application of concrete containing condensed silica fume to the Lianyun Harbor timber warf.