Strength of Concrete Slabs Reinforced with Carbon Fiber Reinforced Polymer under Torsion

Concrete slabs are critical components in structural applications but are inherently limited by their brittleness and low tensile capacity, which can lead to failure under torsional loads. Traditional steel reinforcement provides some resistance but introduces issues, such as increased weight and susceptibility to corrosion. Carbon Fiber-reinforced Polymer (CFRP) materials present a promising alternative due to their high tensile strength, nonmagnetic properties, and resistance to corrosion.

This research employed finite element analysis (FEA) through ABAQUS software to investigate the torsional performance of concrete slabs reinforced with CFRP. A total of 24 square slabs were modeled, comprising 21 CFRP-reinforced slabs and 3 steel-reinforced slabs. The analysis focused on the effects of varying CFRP bar sizes (8 mm, 10 mm, and 12 mm) and compressive strength of concrete (21 MPa to 50 MPa) on the torsional behavior of the slabs.

The results revealed that increasing CFRP bar size and concrete compressive strength significantly enhanced torsional cracking and ultimate moments. The largest increases in torsional cracking and ultimate moments were 4% and 21%, respectively, when the bar size was increased from 8 mm to 12 mm. Similarly, the highest increases in these moments were 53% and 42%, respectively, when the compressive strength increased from 21 MPa to 50 MPa.

These insights are crucial for optimizing the design of CFRP-reinforced slabs in torsional applications.