Title: Performance of Ultra-High-Performance Concrete in Harsh Marine Environment for 21 Years
Author(s): Edward G. Moffatt, Michael D. A. Thomas, Andrew Fahim, and Robert D. Moser
Publication: Materials Journal
Appears on pages(s): 105-112
Keywords: chloride ingress; corrosion; durability; marine exposure; ultra-high-performance concrete
This paper presents the durability performance of ultra-high-performance concrete (UHPC) exposed to a marine environment for up to 21 years. Concrete specimens (152 x 152 x 533 mm [6 x 6 x 21 in.]) were cast using a water-cementitious materials ratio (w/cm) in the range of 0.09 to 0.19, various types and lengths of steel fibers, and the presence of conventional steel reinforcement bars in select mixtures. Laboratory testing included taking cores from each block and determining the existing chloride profile, compressive strength, electrochemical corrosion monitoring, and microstructural evaluation. Regardless of curing treatment and w/cm, the results revealed that UHPC exhibits significantly enhanced durability performance compared with typical high-performance concrete (HPC) and normal concretes. UHPC prisms exhibited minimal surface damage after being exposed to a harsh marine environment for up to 21 years. Chloride profiles revealed penetration to a depth of approximately 10 mm (0.39 in.) regardless of exposure duration.
Electrochemical corrosion monitoring also showed passivity for reinforcement at a cover depth of 25 mm (1 in.) following 20 years.