13.Analysis of chloride resistance performance of CFRP reinforced lightweight aggregate concrete under wet dry cycle

Abstract:

In order to address the issues of heavy self-weight and high cost of ordinary concrete, CFRP reinforcement is combined with lightweight aggregate concrete. Through a combination of macroscopic experiments and scanning electron microscopy, the damage mechanism of CFRP reinforcement in lightweight aggregate concrete under chloride ion erosion is revealed. The study found that with the progression of wet-dry cycles, properties such as the mass and dynamic elastic modulus of CFRP-reinforced lightweight aggregate concrete showed a trend of first increasing and then decreasing. After 50 cycles, the deflection at failure of CFRP-reinforced lightweight aggregate concrete increased by 1.5 mm, and the peak load increased by 5%. In the early stages of the wet-dry cycle, the bonding strength in the interface transition zone between the CFRP reinforcement and concrete increased. However, as the number of cycles increased, the crack width in the transition zone widened, and the bonding capacity between the concrete and reinforcement decreased, leading to a reduction in the specimen's load-bearing capacity.

Keywords: chloride salt erosion;dry-wet cycle;CFRP bars;lightweight aggregate concrete