Study of the interface adherence of geogrid-reinforced asphalt overlays

• Grant number: 19/26459-6
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): April 01, 2020
• Effective date (End): September 30, 2021
• Field of knowledge: Engineering - Civil Engineering - Transportation Infrastructure
• Principal researcher: Natalia de Souza Correia
• Grantee: Gustavo Genaro Urquiza Júnior
• Home Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

The technique of using geosynthetic reinforcements in asphalt overlay restauration is identified as an alternative to increasing pavement service life due to the ability to minimize reflection of pre-existing cracks. In this technique, it is essential that the performance of the interface between asphalt and geosynthetic is as adequate as possible, since it directly interferes with the stresses distribution and deformation in the pavement structure, and thus its serviceability and long-term performance. However, the standard specifications available for this application, even international specifications, treat the project based on field experience, without any rational approach to the interface adhesion parameter. It is also important to highlight that the existing recommendations differ from each other in the geosynthetic installation methodology (asphalt tack coat phase), showing the lack of studies that identify and evaluate the main parameters responsible for the satisfactory performance of this technique. Thus, the present proposal aims to evaluate the interface adhesion behavior between an asphalt overlay and different geogrids by means of interface shear tests (Leutner shear test), varying the rate of asphalt binders. This study will be associated to a search for an optimal impregnation rate for each type of interlayer, as well as evaluation of the influence of interface shear velocity during the tests. Non-reinforced interfaces with different tack coat rates will also be evaluated for comparative purposes. It is expected to generate data to evaluate the interface between asphalt overlays and geogrids that can be implemented in design specifications and thus develop standard specifications with respect to considerations of the interface adhesion parameter. (AU)