Prestress Loss Diagnostics in Pretensioned Concrete Structures with Corrosive Cracking

Concrete cracking induced by strand corrosion can degrade bond strength and lead to prestress loss. A novel model is proposed to predict corrosion-induced prestress loss in pretensioned concrete structures. The coupling effects of concrete cracking and bond degradation are incorporated into the model. An experimental study is conducted to evaluate the effective prestress in eight corroded pretensioned concrete beams under various stress levels. Experimental results are employed to validate the proposed model. Results demonstrate that the proposed model can accurately predict prestress loss in corroded pretensioned concrete structures. Prestress loss depends on the corrosion degree. Corrosion-induced concrete cracking may not degrade bond strength and effective prestress unless corrosion loss exceeds 6.6%. As corrosion further progresses, bond strength and effective prestress decrease monotonically and then reduce to zero when corrosion loss reaches 34.0%. (C) 2020 American Society of Civil Engineers.