External Confined Concrete Cylinders Behavior under Axial Compression Using CFRP Wrapping

Area of Science:

• Civil Engineering
• Materials Science
• Structural Engineering

Background:

• Carbon-fiber-reinforced polymer (CFRP) is a key composite for repairing and strengthening concrete structures.
• Understanding the behavior of confined concrete cylinders (CCC) under load is crucial for structural integrity.
• Externally bonded reinforcement (EBR) is a common technique for applying CFRP.

Purpose of the Study:

• To investigate the confinement effect on concrete cylinders using CFRP under uniaxial loads.
• To analyze the influence of concrete strength, CFRP angle, and volumetric ratio on CCC performance.
• To examine failure mechanisms and mechanical property improvements.

Main Methods:

• Experimental investigation of over 150 CFRP-confined concrete cylinder specimens.
• Testing under axial compressive loads and indirect tensile tests.
• Varying water/cement ratios (0.33-0.522) and sand-resin ratios.

Main Results:

• CFRP confinement significantly improved compressive strength, especially in low-strength concrete (38%-66% increase).
• Transversally confined cylinders showed greater strength gains than longitudinally confined ones.
• Adding sand to resin increased compressive strength (1.19%-54.62%) and reduced material costs.

Conclusions:

• CFRP confinement is an effective strengthening method for concrete elements.
• Optimizing CFRP orientation and concrete mix design enhances performance.
• Sand-modified resin offers a cost-effective solution for CFRP applications.