L VAN PARYS, F DAGRAIN, T DESCAMPS and C COUDYZER
Polytechnic Faculty of Mons, Department of Civil Engineering & Department of Mining Engineering
Rue de Houdain 9 – 7000 Mons – Belgium
For historical mortars, the on-site determination of mechanical properties is sometimes difficult. This paper presents a scratching test (as used daily by the petroleum industry) in order to determine, from a very small piece of mortar, the conventional compressive strength.
First, the paper describes the method : the data recorded during a scratching test are interpreted thanks to a phenomenological model in order to compute the intrinsic specific energy – e – of the material, which is correlated with the Ultimate Compressive Strength [1-3]. Then the paper outlines some adaptations needed to use the method in the field of mortars and presents the results of a calibration programme performed on lab mortars in order to determine the relation between e and the UCS. Finally, the paper depicts an application of this method in the framework of structural interventions performed in the transept of the Our Lady Cathedral of Tournai (UNESCO World Heritage).