EFFECTS OF SHORT-TERM ENVIRONMENTAL EXPOSURE ON AXIAL STRENGTHENING CAPACITY OF COMPOSITE JACKETED CONCRETE

Recent studies from the U.S. Department of Transportation (USDOT) esti mate that of the 575 000 bridges in the nation, 230 000 (or 40%) are e ither structurally deficient or functionally obsolete. The deteriorati on has been caused by a variety of factors including corrosion due to marine environments, high chloride content in the air and use of de-ic ing salts, alkali-silica reactions (ASR), environmental effects on mat erials, poor initial design, and poor construction and maintenance, or both. Cracking and spalling of concrete columns is often seen with co rrosion of internal reinforcement steel due to moisture and chloride i ngress. The loss of cementitious material, as well as the reduction in steel cross-section, leads to drastic reductions in the structural ef ficiency and load-carrying capacity of columnar supporting elements. T he high stiffness-to-weight and strength-to-weight ratios of advanced composites, combined with their inherent corrosion resistance, environ mental durability, and tailorability make them attractive for use in i nfrastructure renewal. In this paper, we investigate the effect of env ironmental exposure on the strengthening efficiency of composite-jacke ted concrete column stubs. The effects of short-term exposure to ambie nt and 0 degrees F conditions as well as to water and sea water on gla ss-, carbon-, and aramid-epoxy jackets is investigated.