Numerical and experimental investigation of the interface of high strength concrete and ultra-high-performance concrete

• Grant number: 23/04403-4
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2023
• End date: August 31, 2025
• Field of knowledge: Engineering - Civil Engineering - Structural Engineering
• Principal Investigator: Lisiane Pereira Prado
• Grantee: Lisiane Pereira Prado
• Host Institution: Faculdade de Engenharia (FEG). Universidade Estadual Paulista (UNESP). Campus de Guaratinguetá. Guaratinguetá , SP, Brazil
• Associated researchers: Emerson Felipe Félix ; Ricardo Carrazedo
• Associated scholarship(s): 25/01437-0 - Investigation of the mechanical properties of Ultra High Performance Concrete with steel and polypropylene fibers considering the initial age and accelerated aging., BP.IC

Abstract

Ultra High-Performance Fiber Concrete (UHPC) has high mechanical properties, good durability and high adhesion. The same is a filling option in connecting precast concrete elements in structural repairs and rehabilitating normal or high-strength concrete structures. The association between concretes creates an interface of the materials. To ensure that the interface of the UHPC with the concrete has good functioning, it is necessary to analyze the strength and stiffness between the materials. In this scenario, the project consists of an investigation of numerical models of the interface behavior of high-strength concrete (HSC) and filler concrete (UHPC). Different factors that influence the behavior of the interface will be considered: variations of the strength of HSC and UHPC, the types of roughness at the interface and the different mechanical tests to characterize the bond strength of the interface, that is, tensile, shear and shear combined with compression. It is intended to study variations of HSC and UHPC mixture using Rice Husk Ash (RHA) as a partial replacement for fine materials to investigate the effects on the bond strength at the interface of concretes. Parametric analyzes will be carried out to determine the combination of mechanical tests that best represents the behavior of efforts at the HSC and UHPC interface. Beyond this, to propose analytical models that represent the interface resistance considering the variations of the strength of high-strength concrete (HSC) and the roughness of the surfaces: exposed coarse aggregate, exposed fine aggregate, shear key, expanded mesh, exposed fiber and an untreated (smooth) reference surface. Therefore, the study aims to contribute to a better understanding of the interface behavior of concretes with UHPC. (AU)