Title: Failure Analysis of Reinforcement Semi-grouting Sleeve Node Connection

Author(s): Jingshuang Zhang, Ruihan Qin, Fei Lv, Yonghua Shu, Yanqing Wu

Publication: Structural Journal

Volume:

Issue:

Appears on pages(s):

Keywords: bearing capacity; grout material; reinforcement connection; semi-grouting sleeve; stress-strain; uniaxial tension

DOI: 10.14359/51740856

Date: 6/3/2024

Abstract:
In this paper, the uniaxial tensile test of semi-grouting sleeve connectors was carried out by controlling the amount of expansive agent in the grout material. The effects of different steel bar diameters and anchorage depths on the failure mode, bearing capacity, and surface strain of sleeve connectors were studied. It is found that there are three failure modes in the specimens, namely, steel bar pull-out failure, steel bar slip failure, and screw thread failure. The expansion characteristics of the grout material can partially compensate for the lack of compressive strength. Based on the analysis of the ultimate bearing capacity of different specimens, a design method to prevent the slip failure of the semi-grouting sleeve is proposed. The addition of 5% to 11% expansive admixture can reduce the circumferential strain of the casing from the steel bar anchorage location to the grouting end by 28.57% ~ 125.30%, with no impact on the longitudinal strain variation pattern. As the depth of steel bar anchorage increases, the expansive effect of the steel bar anchorage and casing longitudinal strain gradually surpasses the shrinkage effect, while the shrinkage effect at the grouting end of the casing gradually outweighs the expansive effect. With an increase in steel bar diameter, the longitudinal strain at the grouting end of the casing only decreases by 1.75% and 2.10%, essentially having no significant impact.