It is now realised that for many concrete structures durability is of a major importance, and that there is a need to minimise the risk of damage due to reinforcement corrosion in the aggressive environment. The vastly improved anti corrosive performance obtained, and the whole life cost benefits, from the use of stainless steel rebar can now be more readily recognised. There is a strong technical and economic case for giving consideration to the use of a rebar that provides the highest possible levels of long term resistance to corrosion, thus greatly reducing the need for maintenance and repair operations. The above case has been recently recognised by Government bodies such as the UK Highways Agency which has now issued the “Design Manual for Roads and Bridges” Volume 1, Section 3, Part 15, BA84 / 02. This paper strongly recommends the use of stainless steel rebar in those elements of the bridges and other concrete highways structures that are at risk from chloride attack. Reval rebar grades 304 S31 (1.4301), 316 S33 (1.4436), Lean Duplex (1.4362) and Duplex (1.4462) show an exceptional resistance to corrosion attack from chlorides, salts and atmospheric agents. Reval rebar offers economic advantages in the medium and long term, as the initial costs of Reval rebar is off-set by significant savings in maintenance costs over the life of the concrete structure.
The benefits of using Reval rebar in concrete on Bridges and other Highways structures, Flood Defence schemes and sensitive buildings are as follows:
- Excellent corrosion resistance to chlorides
- Superior resistance to localised corrosion mechanisms
- The corrosive resistance is unaffected by abrasion damage
- Higher resistance to seismic and shock loading
- Expected service life in concrete of 75 years.
- Very low life cycle costs.
- High strength and ductility.
- Very low magnetic permeability.
Still Going Strong since 1937One of the very best examples of “stainless steel rebar durability” is the Progresso Pier, Mexico. The pier in the background of the photo is over 75 years old and was built using grade 304 stainless rebar. The pier in the foreground was built 40 years ago using carbon steel rebar and has virtually disappeared. In December 1998, Ramboll Consulting Engineers of Denmark inspected the pier and issued a 12 page report, they reported that the pier still performs very well and with no sign of deterioration. They estimated the remaining service lifetime to be at least 20-30 years even without any significant maintenance.