Concrete cracking prediction under combined prestress and strand corrosion

Abstract

This study investigates strand corrosion-induced concrete cracking under various prestress experimentally and analytically. Experimental data on the critical time of cover cracking, crack width and corrosion loss obtained from the accelerated corrosion test are presented and discussed. The expansion ratio of strand corrosion products is estimated based on the infrared spectroscopy and thermal gravimetry. An analytical model, incorporating the coupled effects of prestress and strand corrosion, is proposed to predict the global process of concrete cracking from initiation to propagation. Strand rust-expansion ratio and the residual stiffness of cracked concrete are also included in the model. Results show that prestress can accelerate the corrosion-induced cracking process. By varying prestress from 0 to 75% strand tensile strength, the critical time of cover cracking decreases 22% and the crack propagation rate increases 9%. It is found that the proposed model is accurate in predicting corrosion-induced crack width in prestressed concrete beams.

Keywords:

• Prestressed concrete
• strand corrosion
• corrosion products
• concrete cracking
• crack propagation
• rust-expansion ratio

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The work reported here was conducted with the financial support from the State Key Development Program for Basic Research of China (grant no. 2015CB057705), the National Natural Science Foundation of China (grant no. 51678069, 51708477) and the China Postdoctoral Science Foundation (grant no. 2017M620350). Their supports are gratefully acknowledged.