An Enhanced UHPC-Grout Shear Connection for Steel-Concrete Composite Bridges with Precast Decks

Yongtao Zhang,Minghao Tang,Hehui Zheng,Zhiqi He,Cristoforo Demartino

doi:10.1155/2021/5595174

Abstract

This article develops an enhanced UHPC-grout shear connection for steel-concrete composite bridges with precast decks. The primary improvement is the use of ultra-high performance concrete (UHPC) as the connection grout. To validate the constructability and the mechanical performance of the new connection, two series of experimental tests (including grouting tests and push-out tests) were conducted. Results from the grouting tests show that both the pressure grouting method and the self-levelling grouting method are applicable to inject the UHPC grout into the channel void of the connection. Results from the push-out tests indicate that the advanced properties of UHPC allow for a significant improvement of the shear resistance of the adhesive connection over traditional cementitious grouts. The ultimate shear capacity of the adhesive connection is controlled by the interface shear strength between the embossed steel and the UHPC grout, with a cohesion value of approximately 5.87 MPa. Meanwhile, the residual frictional resistance can be taken as approximately one-half of the ultimate resistance. The results of the finite-element analysis show that the trilinear model is reasonable to simulate the shear-slip laws of the embossed steel-grout interface and the rough concrete-grout interface.

Highlights

Steel-concrete composite bridges using prefabricated fulldepth deck panels allow modular construction and greatly minimizing traffic impacts
Based on the test results, the ultimate shear capacity of the adhesive connection is controlled by the interface shear strength between the embossed steel and ultra-high performance concrete (UHPC) grout [21,22,23]. e longitudinal shear
Based on regression analysis of the test data, the cohesion value can be taken as 5.87 MPa for the embossed steel-UHPC grout interface. e residual frictional resistance can be taken as approximately one-half of the ultimate resistance

Summary

Introduction

Steel-concrete composite bridges using prefabricated fulldepth deck panels allow modular construction and greatly minimizing traffic impacts. E second generation of the adhesive connection is shown in Figure 2(b) by Diogenes et al [6], with the use of high-performance mortar (HPM) and the presence of circular holes in the steel rib to generate a “dowel effect.” this idea comes from the Perfobond shear connectors, in which the shear resistance is expected to be increased considering the confined concrete inside the connector’s openings. A new generation of adhesive connections is developed using UHPC grout to replace traditional cementitious grouts. 2. Objectives is study aims to provide a new generation of the adhesive connection, referred to as the “enhanced UHPC-grout shear connection.” e primary improvement is the use of UHPC as the connection grout.

Comparison of Two Grouting Methods for UHPC

Push-Out Testing of Shear Connectors

Section I-I

Test Results and Discussion

Recommendations and Discussion