Direct shear strength of UHPC-based gravity-type grouted sleeve connection members

Abstract

This study aims to clarify the shear mechanism and strength of a new gravity-type grouted sleeve connection using ultra-high performance concrete (UHPC). Direct shear tests were conducted to investigate the shear performance of the UHPC-based connection. The test results showed that the shear strength of the UHPC-based connection is at least 50% higher than that of the traditional connection. Also, the failure mode of the UHPC-based connection is more like that of the cast-in-place (CIP) specimen than the traditional one. Based on the analysis of the shear mechanism, the formulas were proposed to predict the shear strength of the UHPC-based connection. The shear strengths obtained from the proposed formulas are in good agreement with the experimental data. To further verify the proposed formulas and investigate the shear performance, the finite element (FE) modeling method was also developed for the UHPC-based connection. It was found that the numerical results are consistent with the experimental data and the analytical results derived from the proposed formulas, indicating the applicability of the proposed formulas and FE modeling method. Parametric studies indicated that the shear strength is more sensitive to the axial load level than concrete strengths and reinforcement ratios.