In today’s market, it is imperative to be knowledgeable and have an edge over the competition. ACI members have it…they are engaged, informed, and stay up to date by taking advantage of benefits that ACI membership provides them.
Read more about membership
Become an ACI Member
Founded in 1904 and headquartered in Farmington Hills, Michigan, USA, the American Concrete Institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensus-based standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design, construction, and materials, who share a commitment to pursuing the best use of concrete.
American Concrete Institute
38800 Country Club Dr.
Farmington Hills, MI
Feedback via Email
Home > Publications > International Concrete Abstracts Portal
The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.
Title: Influence of Chemistry of Chloride Ions in Cement Matrix on Corrosion of Steel
Author(s): Ha-Won Song, Min-Sun Jung, Chang-Hong Lee, Sang-Hyo Kim, and Ki Yong Ann
Publication: Materials Journal
Appears on pages(s): 332-339
Keywords: buffering; chloride; corrosion; threshold value
Abstract:To assess the resistance of steel against corrosion, mortar specimens were manufactured with a centrally located steel reinforcing bar. The mortars were formulated by combining ordinary Portland cement (OPC) with a single supplementary cementitious material. The proportions were 30% pulverized fuel ash (PFA), 60% groundgranulated blast-furnace slag (GGBS), or 10% silica fume (SF) by weight. In addition, a pure OPC mortar was prepared. The mortar specimens contained chlorides from 0.0 to 3.0% by weight of binder to accelerate the corrosion process. Then, the corrosion rate was measured by a polarization technique to determine the chloride threshold level for corrosion in concrete. The buffering capacity of the cement matrix to a pH reduction was quantified by measuring the acid neutralization capacity. The suspension consisting of distilled water and paste powder was exposed to nitric acid to characterize a decrease in the pH. As a result, the chloride threshold level for corrosion was dependent on binders, with values of 0.74 to 0.93%, 0.48 to 0.59%, 0.29 to 0.44%, and 0.63 to 0.78% by weight of binder for OPC, 30% PFA, 60% GGBS, and 10% SF, respectively. It was found that an increase in the buffering capacity resulted in an increased threshold value, of which characteristics were used for a new representation of the chloride threshold. The threshold ratio of [Cl–]:[H+] for acidification to a pH value of 10 at corrosion accounted for 0.0063 and 0.0082, irrespective of binder type, at 1.0 and 2.0 mA/m2 (6.50 × 10–4 and 1.29 × 10–3 mA/in.2) of the corrosion rate, respectively.
Click here to become an online Journal subscriber