Mechanical Behaviour and Properties
The indentation technique is tailored here to the needs of a portable tool for in situ diagnosis of mechanical properties and damage of natural building stones. Indentation tests were performed in twelve natural building stones (calcarenites, limestones, sandstones, marbles) and mortars used for restoration. A wide range of mechanical and petrophysical properties with different failure mechanisms in indentation is thus represented. Indicatively, the Unconfined Compressive Strength (UCS) ranges between 3.1 MPa and 116 MPa and the tangent Young’s modulus E 50 at 50% of the maximum stress in uniaxial compression ranges between 0.9 GPa and 50 GPa. The tests were performed with three indenter diameters, 1-, 2- and 3-mm, to analyze scale effects in the results, and at five different depths, as the technique will be used not only for surface measurements but also for measurements in the interior, at the bottom of a small drilled hole. Such measurements can provide information on stone damage with depth. The results are used to build correlation functions and databases between indentation parameters and stone stiffness and strength. The technique is applied to two marbles that had been artificially weathered with exposure to moisture and temperature cycles, and to a consolidated mortar, i.e. a mortar treated with a consolidant for improving its weathering characteristics.
KeywordsUniaxial Compression Indentation Depth Indentation Test Indentation Technique Damage Diagnosis
Unable to display preview. Download preview PDF.
- 5.A.C. van der Vlis, in: Proc. 2 nd Int. Symp. Rock Mech. (1970), Paper 3–4.Google Scholar
- 6.J. Geertsma, Some rock mechanical aspects of oil and gas well completions, SPE J., 848–856 (1985).Google Scholar
- 7.M. Thiercelin and J. Cook, in: Proc. 29 th U.S. Symp. Rock Mech., (Balkema, Rotterdam, 1988), pp. 135–142.Google Scholar
- 8.R. Suárez-Rivera, Z. Zheng, N.G.W. Cook and G. Cooper, in: Proc. 31 st U.S. Symp. Rock Mech., (Balkema, Rotterdam, 1990), pp. 671–678.Google Scholar
- 9.F.J. Santarelli, J.L. Detienne and J.P. Zundel, in: Proc. 32 nd U.S. Symp. Rock Mech., (Balkema, Rotterdam, 1991), pp. 647–655.Google Scholar
- 11.B. Schouenborg, B. Grelk, J.-A. Brundin and L. Alnæs, Bow test for facade panels of marble, NORDTEST Project 1443–1499 (2000).Google Scholar
- 12.B. Grelk, P. Golterman, B. Schouenborg, A. Koch and L. Alnæs, in Proc. Dimension Stone 2004 (2004).Google Scholar
- 13.J. Cohen and P.J.M. Monteiro, Durability and integrity of marble cladding: A state of the art review, ASCE Journal 5 (2), 113–124 (1991).Google Scholar
- 14.K Hook, Look out below – The Amoco Building cladding failure, Progressive Architecture 75, 58–62 (1994).Google Scholar
- 15.T. Yates, J.-A. Brundin, P. Goltermann and B. Grelk, in: Proc. Dimension Stone 2004 (2004).Google Scholar
- 16.P. Tiano, G. Exadaktylos, E. Papamichos, E. Valentini, in: Proc. of the HWC-2006 Heritage Weathering and Conservation Conference (Balkema, Rotterdam, 2006)Google Scholar