Scholar: Dipendra Shrestha
When: Thursday, November 20th at 2:30pm
Where: PKI 150
Zoom: https:// unl.zoom.us/91978515918
Title: EXPERIMENTAL EVALUATION OF CORROSION OF STRANDS AND WIRES TO ESTIMATE CORROSION RATE IN GROUT AND CONCRETE
Abstract: Chloride induced corrosion of prestressing steel remains a leading cause of premature structural failure. Non-destructive parameters such half-cell potential, grout resistivity are routinely used to examine structure health, however the existing guidelines have been developed for reinforced concrete systems.
This research delivers corrosion rate models that capture initiation and propagation phases of corrosion specific to prestressing steel in both concrete and grout. A robust correlation of half-cell potential and surface resistivity of encasing material with corrosion rate was found. Empirical equations developed from the statistical analysis of these correlations will allow reliable long-term deterioration rate forecasting. This study also revealed that for low cathode to anode ratio, total corrosion rate can be multiple times the macrocell corrosion rate. Forensic examination revealed the difference in corrosion mechanisms and chloride ion diffusion rates between concrete and grout.