Structural Behavior Evaluation of Reinforced Concrete Using the Fiber-Reinforced Polymer Strengthening Method

Area of Science:

• Civil Engineering
• Materials Science

Background:

• Aging reinforced concrete (RC) structures experience performance degradation and cracking.
• Reinforcement is crucial for restoring and enhancing the performance of existing RC structures.

Purpose of the Study:

• To evaluate and compare four reinforcement methods for RC structures: near-surface mounting (NSM), external prestressing (EP), external bonding (EB), and section enlargement (SE).
• To investigate the use of fiber-reinforced polymer (FRP) as a reinforcement material, highlighting its advantages over traditional steel bars.

Main Methods:

• Flexural experiments were conducted on RC specimens strengthened using various FRP materials (CFRP, GFRP) and prestressing (PS) strands with the selected reinforcement methods.
• The study examined changes in the ductility of RC structures after applying different strengthening techniques.

Main Results:

• The concrete EP and near-surface mounting prestressing (NSM(P)) methods demonstrated nearly double the stiffness of non-strengthened specimens.
• The EP and EB methods exhibited brittle behavior.

Conclusions:

• The NSM(P) method, utilizing FRP, is identified as the most effective strengthening technique due to its ductile behavior.
• FRP materials offer high tensile strength, corrosion resistance, and lightweight properties, making them suitable alternatives to steel for RC structure reinforcement.