Hybrid composite rods for concrete reinforcement

Abstract

The concrete construction industry deals every day with the deterioration of concrete structures. Nowadays a large number of bridges, buildings and other structural elements require rehabilitation and repair and its maintenance have become an increasingly serious problem. Concrete structures when subjected to repeated loading and to aggressive environmental agents present a decrease in terms of mechanical properties and durability performance. Corrosion of steel is one of the most serious problems of concrete structures. Several techniques have been developed to reduce corrosion of steel but none seems to be a suitable solution for the corrosion problem. Therefore, the use of fibre reinforced composite rods as concrete reinforcement material seems to be an effective solution to overcome durability problems of traditional steel reinforced concrete structures. The main advantages of fibre reinforced composite materials over steel include the excellent corrosive resistance, mechanical properties similar to steel, high strength-to-weight ratio and excellent fatigue resistance, among others. Thus, the replacement of steel rebars with fibre reinforced composite rods is gaining popularity worldwide. The concrete construction industry deals every day with the deterioration of steel reinforced concrete structures. Concrete structures when subjected to repeated loading and to aggressive environmental agents present a decrease in terms of mechanical properties and durability performance. Corrosion of steel is one of the most serious problems of concrete structures. Deterioration of concrete severely affects the service life, safety and maintenance costs of concrete structures. Moreover, reinforced and pre-stressed concrete structures are particularly vulnerable, especially those exposed to moist and aggressive environments. In this case, steel corrodes producing unsightly staining, cracking and spalling of the concrete due to the volume expansion of the iron as the oxide is formed. Stainless steel, galvanizing, epoxy coating and other procedures are some of the techniques that have been developed to reduce steel corrosion, but none of the solutions seem to be viable as suitable solution to eliminate the corrosion problem. Therefore, fibre reinforced composite materials have recently received a great deal of attention by the civil engineering scientific community (Chaallal, 1996) (Micelli, 2004). The advantages of fibre reinforced composite ma