TY - JOUR

T1 - Axial-Load Resistance of a Novel UHPFRC Grouted SHS Tube-Sleeve Connection

T2 - Experimental, Numerical, and Theoretical Approaches

AU - Huang, Z.

AU - Zhang, W.

AU - Fan, S.

AU - Sui, L.

AU - Ye, J.

PY - 2021/11/30

Y1 - 2021/11/30

N2 - Experimental, numerical, and theoretical analyses were conducted of the axial load resistance of a novel ultrahigh-performance fiber-reinforced concrete (UHPFRC) grouted square hollow section (SHS) tube sleeve connection. The experimental study tested 10 full-scale specimens with varying shear key spacings, grout thicknesses, grout lengths, and volume proportions of steel fiber in the UHPFRC. Two types of failure modes were observed: (1) for the connection with high strength of the grouted part, the failure mode was fracture of the inner tube; and (2) for the connection with lower strength of the grouted part, the failure mode was grout shear crushing with significant bond-slip between grout and steel tube. To understand further the load transfer mechanism of the connection, an advanced three-dimensional (3D) nonlinear finite-element (FE) model was built to simulate the axial load-displacement behavior, state of stress and strain, and crack development of the grout. Based on the test and FE results, a new theoretical model was derived to predict the axial-load resistance of the connection. The proposed model considers the effect of section shape and material parameters, and is applicable to UHPFRC grouted SHS tube sleeve connection with different corner radii. Validation versus the test results showed that the new model can provide reasonably effective and accurate predictions of the axial-load resistance of the novel grouted sleeve connection subjected to tension.

AB - Experimental, numerical, and theoretical analyses were conducted of the axial load resistance of a novel ultrahigh-performance fiber-reinforced concrete (UHPFRC) grouted square hollow section (SHS) tube sleeve connection. The experimental study tested 10 full-scale specimens with varying shear key spacings, grout thicknesses, grout lengths, and volume proportions of steel fiber in the UHPFRC. Two types of failure modes were observed: (1) for the connection with high strength of the grouted part, the failure mode was fracture of the inner tube; and (2) for the connection with lower strength of the grouted part, the failure mode was grout shear crushing with significant bond-slip between grout and steel tube. To understand further the load transfer mechanism of the connection, an advanced three-dimensional (3D) nonlinear finite-element (FE) model was built to simulate the axial load-displacement behavior, state of stress and strain, and crack development of the grout. Based on the test and FE results, a new theoretical model was derived to predict the axial-load resistance of the connection. The proposed model considers the effect of section shape and material parameters, and is applicable to UHPFRC grouted SHS tube sleeve connection with different corner radii. Validation versus the test results showed that the new model can provide reasonably effective and accurate predictions of the axial-load resistance of the novel grouted sleeve connection subjected to tension.

KW - Axial-load resistance

KW - Friction and adhesion

KW - Shear key

KW - Sleeve connection

KW - ultrahigh-performance fiber-reinforced concrete (UHPFRC)

KW - Axial loads

KW - Concrete construction

KW - Failure modes

KW - Fiber reinforced concrete

KW - Mortar

KW - Steel fibers

KW - Tubes (components)

KW - Tubular steel structures

KW - Load transfer mechanism

KW - Load-displacement behavior

KW - Non-linear finite elements

KW - Square hollow sections

KW - Theoretical approach

KW - Theoretical modeling

KW - Threedimensional (3-d)

KW - Ultra-high-performance fiber-reinforced concrete

KW - Grouting

U2 - 10.1061/(ASCE)ST.1943-541X.0003189

DO - 10.1061/(ASCE)ST.1943-541X.0003189

M3 - Journal article

VL - 147

JO - Journal of Structural Engineering

JF - Journal of Structural Engineering

SN - 0733-9445

IS - 11

ER -