Evaluating Flexural Performance of Repaired Reinforced Concrete Beams under Static and Repeated Loading Using...

Area of Science:

• Civil Engineering
• Materials Science

Background:

• Concrete structure deterioration is a significant construction industry challenge.
• Repair and rehabilitation are crucial for extending the service life of aging infrastructure.

Purpose of the Study:

• To investigate the impact of repair material type, repaired region length, and loading conditions on reinforced concrete (RC) beams.
• To evaluate the effectiveness of different repair strategies for damaged concrete structures.

Main Methods:

• Prepared and tested 30 repaired and non-repaired RC beams under static and repeated loading.
• Utilized three sounding-based non-destructive testing (NDT) methods to assess material deterioration and delamination.
• Compared experimental results with predictions from Canadian Standards Association (CSA) 23.3 formulas.

Main Results:

• Full-length repairs outperformed 1/3-span repairs under static loading, with yield strength improvements of 14% and 9% for specific repair materials.
• All fully repaired beams surpassed the performance of intact beams.
• Repeated loading showed a 14% yield strength improvement in fully repaired beams with modified binder cementitious repair compared to controls.
• High compressive and flexural strength repair materials proved beneficial.
• Resonant frequency drops correlated well with yield strength outcomes.

Conclusions:

• Full-span repair strategies, particularly with high-strength materials, significantly enhance the structural performance of RC beams.
• The Canadian Standards Association (CSA) 23.3 formulas accurately predict the moment resistance of both intact and repaired RC beams.
• Sounding-based NDT methods are effective for evaluating post-repair structural integrity.