Performance of plain and galvanized reinforcing steel during the initiation stage of corrosion in concrete with pozzolanic additions

Book · Thu Oct 31 23:00:00 EST 1996

OSTI ID:382568

Moreno, E I; Saguees, A A ^[1]; Powers, R G ^[2]

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1. Univ. of South Florida, Tampa, FL (United States). Dept. of Civil and Environmental Engineering
2. Florida Dept. of Transportation, Gainesville, FL (United States). Materials Office

The pH of the concrete pore solution is expected to be somewhat lower in concretes using pozzolanic additions than in concrete using unblended cements. Variations in pH pore solution may hold the key to explaining conflicting reports on the performance of galvanized rebar. To examine that factor, plain and galvanized rebars have been tested for over two years in concrete specimens made with cement type 2, with various contents of fly ash and silica fume. Electrochemical impedance measurements and sensitive polarization techniques have been used to measure the rate of metal dissolution in the absence of chloride contamination at two different levels of concrete moisture. The plain steel specimens have shown little tendency for passivation in two of the cement compositions with the highest levels of pozzolanic addition. The galvanized steel passivated in all cases and showed apparent corrosion current densities of less than 0.3 {micro}A near the end of the test. Implications of the length of the corrosion initiation period and on current materials selection criteria are presented.

• OSTI ID: 382568
• Report Number(s): CONF-960389--
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
36 MATERIALS SCIENCE
CORROSION
CURRENT DENSITY
ELECTRIC CONDUCTIVITY
ELECTRIC POTENTIAL
ELECTROCHEMICAL CORROSION
EXPERIMENTAL DATA
FLY ASH
PASSIVATION
PH VALUE
REINFORCED CONCRETE
ROADS
SAMPLE PREPARATION
SERVICE LIFE
SILICA
STEELS
TIME DEPENDENCE
ZINC