(Photo credit: New York State Thruway Authority)
For over a century, hot-dip galvanized reinforcing steel has been protecting concrete structures around the world, helping to extend their lifespans and reduce maintenance costs. From early projects like concrete water tanks to iconic modern-day landmarks, galvanized reinforcing steel has a storied history of durability in harsh environmental conditions. In this post, we’ll explore the origins of this material, its rise in usage, and its lasting impact on infrastructure around the world.
Origins of Galvanized Reinforcing Steel
Hot-dip galvanizing, a coating process whereby steel is immersed into a molten zinc bath, has been used to protect steel from corrosion since the 19th century. However, it wasn’t until the early 1900s that galvanized steel was first applied in concrete. One of its earliest uses was to strengthen concrete water tanks, where galvanized wire was used to pre-stress the tank walls, protecting them from water-induced corrosion.
Post-WWII Era and Expanding Use
After World War II, galvanized reinforcing steel gained popularity, especially in the United States. During the 1960s and 1970s, highway and bridge projects in particular saw widespread use of galvanized steel as a way to improve durability and reduce maintenance. For example, by 1963, the iconic Sydney Opera House was being constructed with galvanized steel chevron tile assemblies, providing over 60 years of recorded corrosion protection.
Landmark Projects and Rising Demand
With increased infrastructure demands and a growing awareness of the costs associated with corrosion, the use of galvanized reinforcing steel continued to rise. Since 1995, every New York Thruway Authority bridge project has incorporated galvanized steel, and periodic tests have shown the steel to remain in excellent condition decades later. The durability of galvanized steel reinforcement can be modelled using conventional industry models, and galvanized steel’s durability in real-world conditions often surpasses expectations.
Galvanized Reinforcing Steel Today
Today, galvanized reinforcing steel is widely recognized as a cost-effective, durable solution for concrete projects in environments prone to corrosion, such as coastal and industrial areas. Its unique properties not only reduce the likelihood of carbonation and chloride-induced corrosion but also prevent rust stains, making it ideal for exposed elements like external facades and surface panels.
The ongoing success of galvanized steel in concrete applications has not only contributed to the longevity of iconic buildings and bridges but has also opened new possibilities for durable infrastructure around the world.
By understanding the historical applications and proven durability of galvanized reinforcing steel, we can make more informed decisions about protecting our structures against the costly effects of corrosion.
For further technical details, download the full Concrete Guide from the Galvanizers Association of Australia here.
