No abstract

Portland cement concrete is the most used material in civil construction, but it is a source for emissions of greenhouse gases. In addition, its Interfacial Transition Zone (ITZ) is a point of weakness, which limits its performance and application, generating pathological manifestations throughout its service life, decreasing mechanical and durability properties. In this context, geopolymer concretes, which are a sustainable building material with a much reduced and dense ITZ when compared to ordinary cement Portland materials, arise. However, there is a lack of methodology to evaluate the aggregate-geopolymer interface and objectively evaluate compatibility between such new binder and aggregate particles. In other materials, adhesion tests are performed to obtain parameters related to adhesiveness. Provided that context, this work aims to propose a methodology to evaluate the adhesiveness of aggregates and geopolymer binders. For this, a pull-off test based on AASHTO TP 361 ( 2022) is proposed, with particular adaptation in specimens preparation. The proposed changes such as: the application of the binder and the use of epoxy glue aimed to guarantee the bonding of pull-off elements (dollies) to a geopolymer binder lm adhered to the aggregate and to make the test and its results possible for evaluations. For validation, it was performed for an interface a geopolymer binder based on y ash and steel slag glued onto two granitic rocks (biotite). For the test according to AASHTO TP 361 (2022), the adhesion between the geopolymer binder and the equipment proved to be insu cient. Then, with the adapted methodology the results were more consistent, in which the specimens showed suitable adhesion for the test. This contributes to an empirical characterization of adhesiveness for these materials, enabling adequate analyses regarding the durability, in order to avoid future pathologies resulting from a weak ITZ and evaluations without huge costs in time and resources.