Corrosion behavior of ASTM A416 tendon steel in wet conditions under various chloride concentrations

This study examines the corrosion behavior of steel tendons for prestressed concrete (PSC) structures under varying chloride concentrations and [Cl - ]/[OH - ] ratios. Tendons were exposed to controlled wet conditions, with chloride concentrations ranging from 0.0 to 0.25 mol/L, and [Cl - ]/[OH - ] ratios from 0.3 to 0.9. Results showed significant corrosion even at low chloride levels, with corrosion current density escalating from "high-risk" to "severe" as chloride concentration increased. The study also found that complete grouting is critical, as tendons exposed to humid environments without proper protection corrode significantly, irrespective of the chloride content. The findings suggest that traditional "critical chloride content" concepts may not apply to PSC tendons, highlighting the need for meticulous grout quality control to prevent corrosion. This research provides essential insights into the factors influencing tendon corrosion, offering guidance for improving PSC durability. • Corrosion risk increases with chloride concentration in PSC tendon environments. • [Cl⁻]/[OH⁻] ratio impacts corrosion current density in tendons. • Corrosion observed even at low chloride levels, challenging critical chloride concepts. • Study emphasizes grout quality over chloride limits for PSC durability.