Characterization of the strength and the abrasiveness of stones based on a scratching test F. Dagrain 1 1 University of Mons, Civil Engineering Department, Rue du Joncquois 53, 7000 Mons, Belgium fabrice.dagrain@umons.ac.be Abstract It is well known in the metal industry that cutting tools and their technological parameters have to be correctly chosen depending on the application and the type of material to machine. This is also the case for the stone industry, where the choice of the tools is most of the time based on the experience of the operators who are used to work with very specific types of stone. When a new type of stone has to be sawed, it is important to identify correctly its characteristics. Amongst the most important properties related to cutting mechanisms and tool life span, strength and abrasiveness are for sure the properties which should be determined in any case to identify the most adapted cutting tool. Keywords Strength, abrasiveness, cutting, wear, tool selection 1 INTRODUCTION The Civil Engineering Department of University of Mons is developing its own methods to characterize the stone properties based on alternative techniques which can be applied on very small samples that cannot be tested following standard procedures [1]. Amongst the stone properties studied, strength and abrasiveness are two properties on which we are currently working. Their characterization is important for the development of phenomenological models in order to better simulate the cutting and wear mechanisms. Based on our experience in rock cutting, we are also more and more consulted to characterize both properties in order to advice tools manufacturers to adapt their technology to given applications and to help customers to select competitive tools based on a scientific approach, and more generally to improve the sawing and/or drilling technologies. Many researchers have worked in the past to characterize both properties and our goal is not to review them in this paper, but to describe our methods and their advantages or limitations. 2 THEORETICAL APPROACH OF ROCK CUTTING Rock cutting has been widely described in the literature. Copur [2] gives a recent overview of the main researches undertaken for stone cutting applications. Richard [3] demonstrates that two types of failure mechanisms occur depending on the depth of cut. The ductile mode occurs at shallow depth of cut and is characterized by a continuous flow of particles in front of the tool, while the brittle mode occurs at larger depth of cut and is characterized by cracks propagation generating large cuttings. Detournay and Defourny [4] developed a phenomenological cutting model valid in the ductile mode of failure. This model assumes that any type of cutting tool presents two surfaces in contact with the stone being cut: the cutting face and the wear flat. It has been proved that the cutting mechanisms occurring on the cutting face are independent of the frictional contact on the wear flat. Both types of mechanisms may thus be studied separately. 2.1 Cutting response of a sharp tool It has been largely developed in the literature that the force acting on a sharp tool while cutting is varying with the cross sectional area of the cut and a strength parameter.