Protective Systems for New Prestressed and Substructure Concrete

摘要

A three-year corrosion research project on 11 corrosion protection systems was undertaken in two laboratory studies. A total of 124 small reinforced concrete slabs were subjected to a 48-week, cyclic wet and dry saltwater exposure in the first study. The second year-long study dealt with cyclic saltwater exposure on 19 full-size sections of reinforced concrete columns and beams and precast, prestressed piles and stay-in-place bridge deck panels. The slab tests evaluated concrete having w/c ratios of 0.51, 0.40 and 0.28 with clear cover of 1, and 3 in. The reinforcing steels evaluated were normal gray bars, normal prestressing strands, galvanized bars, and fusion-bonded epoxy-coated bars and prestressing strands. A calcium nitrite corrosion-inhibiting admixture for fresh concrete was evaluated. Design considerations are suggested for these different corrosion protection materials to provide for greater corrosion protection for new cast-in-place reinforced concrete and precast, prestressed concrete bridge members.