The aging and structurally deficient concrete infrastructure is one of the serious and expensive problems faced by public and construction agencies worldwide. In the past few decades, the construction industry has focused primarily on designing corrosion prevention and control systems for roads, bridges, plants, waterside buildings, water tanks, etc. As the old and deteriorated infrastructure reaches the end of its expected lifetime, governing authorities put emphasis on rehabilitating and extending the life of these structures.
In the US, there are approximately 600,000 bridges and the majority of them are steel-reinforced. More than 15% (ref Rita) of bridges are structurally deficient due to the corrosion of reinforced steel. Governments spend billions of dollars annually as a corrosion cost to replace and rehabilitate the deteriorated bridges. Corrosion is the primary factor affecting the reliability and durability of concrete members. It is difficult, if not impossible, to control corrosion-induced deterioration process using conventional materials and construction techniques.
Direct corrosion cost is in billions, but the indirect costs in forms of traffic delays and user inconvenience increase expenses tenfold. The bridge management authorities usually have limited funds to deal with new constructions, rehabilitation activities, and maintenance. Therefore, it is important to develop and utilize modern materials capable of eliminating the corrosion-related problems permanently and cost-effectively.
The civil engineering community and researchers and have been striving to develop reliable technologies and construction practices to control corrosion-related issues for decades. The development and incorporation of corrosion control strategies still demand widespread changes in government policies and industry management.
Effective corrosion solutions
FRP composites are emerging construction materials of the 21st century. These materials have the potential to construct corrosion-free concrete members no matter the environment. For instance, GFRP reinforcement rebar, a variant of FRP composites, offers practitioners and bridge engineers a solid alternative to resolving practical problems of steel-reinforcement in the harsh environment and where electrical and magnetic sensitivity is a concern. The advanced composite materials can be used in both new and rehabilitation applications. The implementation of these sustainable construction materials can save billions of dollars.
As a sustainable construction material, GFRP reinforcement offers high strength, corrosion-resistance, fatigue-resistance, consistent quality and extended service life. In-practice data and studies have concluded that structural performance of FRP composites is far better than conventional materials. Design guidelines of FRP for bridge applications have been considerably developed and incorporated into existing ACI guides. The civil engineering community should explore and implement FRP technology at large scale in order to build maintenance-free and long lasting concrete structures.