Mechanical behavior of half-grouted sleeve connection under the coupling of sulfate erosion and dry-wet cycles

The half-grouted sleeve connection (HGSC) is commonly used in precast concrete (PC) structures due to its convenient fabrication method, however, the long-term mechanical properties of the HGSC in corrosive environments remain unclear. Therefore, the mechanical behavior of HGSC under the coupling of sulfate erosion and dry-wet cycles (DWCs) is investigated in this paper. A total of 24 specimens with 4d and 8d embedded lengths were designed and subjected to sulfate erosion with different DWCs. The failure modes and mechanical properties of HGSCs with different embedded lengths and DWCs were comparatively analyzed. Following this, a modified bond-slip model considering sulfate erosion was proposed and validated against the measured data. The test results indicated that the failure modes of HGSCs with 4d and 8d embedded lengths were rebar fracture and slip failure, respectively. As the number of sulfate erosions increased, the performance indicators of HGSCs gradually decreased. After 180 dry-wet cycles (DWCs), the average deformation and average slip under peak load for HGSCs with an embedded length of 8d decreased by 36.6 % and 37.7 %, respectively. In contrast, for HGSCs with an embedded length of 4d, the corresponding values increased by 3.0 % and 40.1 %, respectively. The predicted bond-slip model of HGSC considering sulfate erosion agreed well with the experimental results, and it can be useful in the life-cycle modeling of the PC structures with HGSCs.