Influence of Stay-in-Place Forms on Concrete Bridge Deck Corrosion

This research is focused on the influence of stay-in-place (SIP) forms on the corrosion of reinforcement in concrete bridge decks. The laboratory study plan contained a total of 27 specimens—nine cells of three specimens each. The nine cell test conditions were with and without SIP forms, one and two cathode bars for each anode bar, and spacing distances between cathode and anode of 2, 3, and 4 in. (51, 76, and 102 mm). The specimens were maintained at a constant temperature and humidity throughout the 45-month chloride ponding cycles with testing periods between 0 to 14 months and 35 to 45 months. Corrosion testing during the two test periods included concrete resistivity, half-cell potential, corrosion rate, and macrocell currents with chloride concentrations and autopsies at 45 months. The effects of SIP forms on micro- and macrocell corrosion of reinforcement were investigated by statistically comparing the performance of specimens with and without SIP forms. It was determined that microcell corrosion was the principal corrosion mechanism. The presence of SIP forms showed a reduction in macrocell currents; however, it had no significant influence on the corrosion rate of steel reinforcement.