Freeze—Thaw Behaviours of Half Grouted Sleeve Connections with High-Performance Grout

Abstract

Grouted sleeve connections with high-performance grout have superior mechanical properties at room temperature, but there is inadequate evidence to prove that they have good resistance to freeze—thaw effects. This paper presents a freeze—thaw experimental study on the tensile behaviour and bond behaviour of grouted sleeve connections with antifoaming agents, early strength agents, and expanding agents. First, the damage appearance, mass loss, and compressive strength loss were studied to determine the freeze—thaw damage mechanisms of grout with different admixture contents, and three optimal composition ratios were chosen for further study. Then, grouted sleeve connections were subjected to tensile tests after different freeze—thaw cycles, and the damage modes and damage mechanisms were studied. The tensile strength of pure rebar was predicted to increase linearly with the number of cycles. For the rebar fracture specimens, the tensile strength of grouted sleeve connections was mainly derived from the tensile strength of the pure rebars and increased linearly with the number of cycles. The experimental results may provide a significant reference for grouted sleeve connections under freeze—thaw conditions.