Fibre Reinforced Polymer Composites in Construction
topic
Fibre reinforced polymer (FRP) composites use glass (GFRP), carbon (CFRP), aramid (AFRP), or basalt (BFRP) fibre textiles as reinforcement in polymer matrices for structural strengthening, rebar replacement, and bridge deck construction. GFRP rebar (glass fibre volume fraction Vf = 55–70%, vinyl ester or epoxy matrix, tensile strength 700–1,000 MPa, modulus 40–50 GPa, density 1.9–2.1 g/cm³) provides corrosion-free concrete reinforcement at 25% weight of equivalent steel rebar — critical for marine, highway bridge, and MRI facility construction. Externally bonded CFRP laminates (unidirectional, 1.0–1.4 mm thick, Vf = 65–70%, tensile strength 2,800–3,500 MPa, modulus 165–210 GPa) bonded with epoxy adhesive (2–4 mm bond line) to concrete beams increase flexural capacity by 30–100% at installed cost of $80–150/m². Near surface mounted (NSM) CFRP strips (2×16 mm, inserted in 5×20 mm saw-cut grooves, epoxy grouted) provide 50–150% shear capacity increase in deficient RC beams. Basalt fibre rebar (tensile strength 1,000–1,200 MPa, modulus 45–55 GPa, alkali resistance superior to E-glass) offers 30–40% cost advantage over CFRP for structural applications. FRP jacketing of circular RC columns (CFRP wrap 2–5 layers, 0.167 mm/ply, confinement ratio fl/fc' 0.05–0.30) increases axial compressive strength by 20–80% and ductility by 200–500% for seismic retrofit. Global construction FRP composites market exceeds $2.2 billion.
Role
FRP composites provide construction engineers with high-strength, lightweight, and corrosion-resistant reinforcement solutions that extend the service life of new and existing concrete infrastructure by eliminating the electrochemical rebar corrosion mechanism responsible for $500 billion annual global infrastructure deterioration costs.