MAADI Group Now Builds Pedestrian and Bicycle Bridges

The key challenge in this emerging market is controlling lifelong maintenance costs. That’s why MAADI Group exclusively uses aluminum for these bridges—an advanced, eco-friendly material with an essentially unlimited lifespan. Their aluminum alloys offer exceptional benefits, including mechanical strength comparable to mild steel, the traditional material for pedestrian bridges.

CQRDA Study Supports Aluminum for Bridge Construction

A study on the maintenance cost of a steel pedestrian bridge built according to the Canadian Highway Bridge Design Code Products (CSA S6-05) was commissioned in April 2010 by the Centre québécois de recherche et de développement de l’aluminium (CQRDA). Conducted by engineer and scientist Frank Ajersh, a retired professor at the École Polytechnique de Montréal, the report strongly endorsed using aluminum for such bridge projects.

MAADI Group’s 50-Year Cost Comparison of Aluminum vs Steel

Based on Prof. Ajersh’s study and the same CSA S6-S5 standard, MAADI compared costs for two similar bridges—one in steel and the other in aluminum—over a 50-year period. Although the steel bridge’s purchase cost was some 20% lower, it became far less attractive once actual operating costs over 50 years were taken into account. Internal results of the MAADI Group’s study are astonishing. When we calculate the constant maintenance required to keep a “less expensive” steel bridge from rusting over 50 years and consider a residual value from the ‘scrap metal’, the cost of the steel bridge (based on Prof. Ajersh’s study) will vary from 233% to 406%¹ from its aluminum counterpart.

Read the complete study

Expert Insight: Aluminum’s Longevity and Sustainability

Alex de la Chevrotière, an aluminum structural design specialist said, “The Canadian Bridge Code requires a lifespan of 75 years. We don’t need to extend our cost studies over a period of more than 50 years to realize that if municipal tendering specifications factored in a structure’s full service life and not just its purchase cost, aluminum would help cut expenses dramatically, while contributing to sustainable development and respect for the environment. Unfortunately, the issue is one of education. Engineers and architects are not aware of all the possibilities that aluminum affords.”

Aluminum’s Natural Corrosion Resistance and Recyclability

Because the oxide layer that naturally forms on the surface of aluminum provides permanent corrosion resistance, this material can be endlessly recycled without losing its properties. Aluminum is also well suited to the economic, technical, environmental and aesthetic demands of this growing market.

Versatile Applications of MAADI Group Aluminum Bridges

MAADI Group aluminum bridges — with spans up to 53 m and clear widths up to 3.7 m — are ideal for applications such as:

• Expanding existing bridges

• Golf courses and property crossings

• Naval and marine facilities

• Bike paths and recreational trails

• Elevated walkways between buildings

• Bridges for snowmobiles and all-terrain vehicles (ATVs)

¹ The extent of this difference depends on the coating used to protect the steel. Prof. Ajersh’s costs analysis employed methods developed by Riena et al.² and Helsel et al.³.

Bibliography for Prof. Ajersh’s Study

² M. P. Reina, K.R. Shields and M.F. MeLampy, “Costing considerations for maintenance and new construction coating work,” Corrosion 98, NACE International, paper No. 509.
³ J.L. Helsel, R. Lanterman and K. Wissmar, “Expected service life and cost considerations for maintenance and new construction protective coating work,” Corrosion 2008. NACE International, paper No. 08279.