Numerical Simulation of the Load Transfer Mechanism at UHPC–UHPC Interface

Abstract

Ultrahigh performance concrete (UHPC) has been used in a different range of applications, especially in bridge construction, due to its outstanding mechanical properties, ductility, and long-term durability. There has been a rapid increase in the use of precast UHPC systems. The weakest link in the UHPC precast system is the interface between the precast UHPC components. The interfacial bond performance between UHPCs cast at different times plays a key role to ensure a load transfer and to achieve a composite behaviour. It has been experimentally proven that the exposed fibers using pressure washing or grooved surface preparations are an effective method to treat the UHPC<span style="left: calc(var(--scale-factor)*146.90px); top: calc(var(--scale-factor)*359.35px); font-size: calc(var(--scale-factor)*12.00px); font-family: sans-serif;" role="presentation" dir="ltr">–</span>UHPC interface, but the numerical simulation and appropriate modeling remain under-investigated. This study focuses on the numerical simulation of the interfacial bond strength using finite element modeling (FEM). The traction-separation relationship with parameters derived from an experimental program were used to calibrate and validate the FE model. The model used information obtained from specimens tested under tensile, shear, and a combination of compression-shear stresses. This paper discusses the modeling of the interface between UHPC cast at different times to accurately simulate the failure mode and load transfer at the interface.