New insights into the use of drilling test for the characterization of soft lime mortars

In this paper, the results of drilling tests performed on different formulations of aerial lime mortars are presented. A new methodology of analyzing results is proposed to overcome the well-known difficulties in the back-analysis of soft mortar drilling profiles, due to their scattering. A new parameter (A) is introduced, which showed a good correlation with porosity, ultrasonic pulse velocity, and uniaxial compressive strength of the mortars. A, used together with the other drilling parameters in bilinear models, improved their correlations with the compressive strength. The influence of the drilling setting conditions on the frequency distribution of the drilling forces is also investigated. It was found that the ratio between the penetration rate and rotational speed strongly affected the shape of the distributions.