Reliability, durability, and safety are of colossal significance when it comes to the design and construction of concrete infrastructure. It is absolutely crucial to reduce the traditional defects of reinforced concrete in order to build structures that can achieve long service life. Fiber reinforced polymer (FRP) reinforcement has turned out to be a remarkable construction material that can increase the strength parameters of reinforced concrete. This blog post will provide a brief introduction to FRP composite materials used as reinforcement in concrete structures.
Over the past couple of decades, FRP composites have developed into a structurally and economically viable construction solution for bridges, marine structures, and buildings. They are manufactured in a variety of forms with varying properties and manufacturing processes. Typical FRP composite materials used in civil engineering are consisted of glass, carbon, and aramid. These materials are either supplied as a ready-to-use material, such as rebar, or they are provided in individual constituent forms, such as fiber and polymer resin.
The incredible performance of composite materials as concrete reinforcement makes it an attractive alternative to conventional reinforcement materials. The applicability of fiber reinforced polymer bars to civil structures as a substitute for steel tendons and bars has been thoroughly researched and analyzed. A large number of studies regarding the structural feasibility and in-practice performance of advanced composite materials are available. Corrosion resistance, high tensile strength, and ease of installation are some of the prominent features of FRP bars that can help build sustainable concrete structures.
In order to obtain the optimum combination of material properties, the quality of constituent materials and the manufacturing process need to be maintained at a higher level. For instance, the physical and mechanical properties of the matrix can have a great impact on the final mechanical properties of bars. Pultrusion is a common manufacturing process that is employed to produce continuous lengths of FRP bars. The surface of the composite bars is coated with a thin layer of sand in order to facilitate an excellent bond between concrete and bars.
Glass fiber reinforced polymer (GFRP), one of the variants of FRP, is a competitive concrete reinforcement option in concrete members subjected to severe environmental conditions. Being a corrosion resistant and electromagnetically transparent construction material, GFRP reinforcement is a promising material for structures that operate in marine and sensitive environments. Following are some of the ideal applications of GFRP rebar:
- Structures built in potentially corrosive environments: bridge decks, retaining walls, public transport infrastructure, roads, etc.
- Structures built near the sea water: piles, decks, pools, floating structures, boat ramps, seawalls, building, etc.
- Structures exposed to severe corrosive agents: power plants, water treatment plants, cooling towers, airport runways, etc.
- Applications that demands electromagnetic neutrality: MRI units, telecommunication facilities, research facilities, military structures, etc.
- Temporary concrete structures: mining, tunneling, boring, etc.
Following the extensive research, design codes, and the availability of in-practice data, civil engineers are increasingly showing confidence in GFRP reinforcement products. FRP composites, undoubtedly, are the construction material of the 21st Century.