Title:
Failure Analysis of Reinforcing Semi-Grouted Sleeve Node Connection
Author(s):
Jingshuang Zhang, Ruihan Qin, Fei Lv, Yonghua Shu, and Yanqing Wu
Publication:
Structural Journal
Volume:
121
Issue:
5
Appears on pages(s):
99-108
Keywords:
bearing capacity; grout material; reinforcement connection; semi-grouted sleeve; stress-strain; uniaxial tension
DOI:
10.14359/51740856
Date:
9/1/2024
Abstract:
In this paper, uniaxial tensile testing of semi-grouted 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 pullout 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-grouted 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 to 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.