Author: Dritan Topuzi
Bridges and barrier walls are often constructed of reinforced concrete, a material where the low tensile strength of concrete is compensated by the high tensile strength of steel. Steel rebar is commonly used within the concrete, however, certain properties of steel, such as electrical conductivity, magnetism, thermal conductivity, and most importantly, low resistance to corrosion, may negatively affect the performance of a reinforced concrete bridge.
Depending on the application and conditions of the structure these properties of steel can affect the performance of bridges. Corrosion control is crucial in reinforced concrete bridges, especially when exposed to de-icing salts. Corrosion of steel reinforcement in bridges causes increased maintenance cost, and if not properly maintained, it affects aesthetics and can lead to structural collapse.
These corroded bridges are found practically everywhere. The Gardiner Expressway in Toronto is a prime example of steel rebar corrosion, and was best described in an article by Dr. Paul Gauvreau on The Globe and Mail, “Toronto’s crumbling Gardiner: Bring on the engineering innovation.”
“…Gardiner was built with materials and structural details that make it prone to deterioration and difficult to maintain…”
More projects are considering GFRP reinforcement as an alternative to steel, bringing in the need for continuous research, whether for new applications or optimizing existing ones.
As always, Schöck has continued to invest on further researching ComBAR® properties and applications, collaborating with research institutions in North America as well as Europe.
Annual Ontario Concrete Awards Banquet honors the most creative and visionary projects that have made concrete their construction material of choice. This year it was held on the 28th of November at the Metro Toronto Convention Center, in Toronto.
Awards are given for the following categories: Architectural, Structural, Materials & Constructability, and Sustainability. ComBAR® GFRP, as an innovative material, provided points to the Whitemans Creek Bridge project, which received the Structural Design Innovation Award, in the Structural Category.
Last week I had the chance to attend two important conferences in Toronto and Mississauga.
The first one was the ACI Fall 2012 Convention, at Sheraton Centre in Toronto. ACI (The American Concrete Institute) is one of the world’s leading authorities in concrete technology. It conducts two conventions a year and this Fall the event was held in Toronto. Domenico and I attended the Convention for two days, the 22nd and 23rd of October, where we introduced Schöck and our products to several potential clients. An important event was the ACI 440 Committee meeting. ACI 440 is an ACI Committee focused on fiber-reinforced polymer reinforcement. During this meeting we heard good news about the Committee’s plans with regard to further developments of codes and guidelines related to the FRP reinforcement in concrete structures. At the end of the meeting we talked to Mr. Busel, a director at ACMA (American Composites Manufacturers Association), and Dr. Shield, the ACI 440 Committee Chair. We have an application in process for becoming a voting member of this Committee, in order to have our say as a local FRP supplier on the future development of codes published by this prestigious institute. … read more