Investigation of the damage of L-HPC under stress corrosion

Abstract

This paper presents a study on the performance damage of lightweight aggregate high performance concrete (L-HPC) under stress corrosion. While L-HPC was undergoing accelerated corrosion in 15% NaCl solution, it was continuously loaded for 90 d, 180 d and 270 d at stress levels with initial L-HPC peak loads of 0%, 50%, 70%. The chloride ion content change, mechanical property deterioration and microstructural damage of L-HPC were studied in detail. The results show that: The dense structure of L-HPC makes it free from obvious cracks at high stress levels (70% peak load), and the quality does not change significantly. The internal curing effect of the lightweight aggregates makes the interfacial transition zone more dense, which hinders the intrusion of chloride ions. The deterioration of L-HPC was slowed down at the initial stage of stress corrosion, but aggravated at the later stage of stress corrosion due to the corrosion of steel fibers.

Keywords

• High performance concrete
• Internal curing
• Stress corrosion
• Chloride content