Experimental investigation of the mechanical properties of Alfas stone

Abstract

This paper focuses on the experimental investigation of the mechanical properties of the Alfas natural building stone. Two series of uniaxial compression tests and indirect tensile tests (Brazilian tests) were performed in order to determine the uniaxial compressive strength and the indirect tensile strength respectively. Different sets of cylindrical specimens and circular discs were prepared by varying their geometry in order to examine the size effect on the respective strength values. Also, the size effect was investigated with respect to the calculated intact rock modulus and Poisson's ratio. All specimens were prepared by following the ISRM suggested methods and the load was applied using a stiff 1600 kN MTS hydraulic testing machine and a 500 kN load cell. Strain was measured using biaxial 0/90 stacked rosettes appropriately attached on each specimen.

Loading rate conditions and specimen size effect on strength and deformability of rock materials under uniaxial compression

“…In this study, core diameters of 32 mm and 54 mm were compared to investigate a 1.7 times change in size of the core specimens with the ratio of length to diameter of 2. Therefore, findings of this study should be considered for that kind of size variation and not be used for generalization since relation between UCS values can change for different variations in specimen sizes [21][22][23].…”

Experimental characterization and numerical modeling of the fracture process in banded Alfas porous stone

“…It is characterized by open porosity of 17.92% (±1.58) and apparent density of 2653 kg/m 3 (±85). 9 The determination of open (effective) porosity and apparent density is based on BS EN 1936(2006 standard. 20 The texture is relatively massive, and its color is usually whitish beige.…”

“…The present study was motivated by the results of a previous research effort 9 in which the banded Alfas porous stone (porolithos) excavated in Rethimnon, Crete, Greece, was considered as a substitution stone in a restoration project. In the previous study, 9 the variation of the uniaxial compressive strength, the indirect tensile strength, the intact rock elastic modulus, and the Poisson's ratio versus a critical size (diameter) were presented and critically discussed.…”

“…The present study was motivated by the results of a previous research effort 9 in which the banded Alfas porous stone (porolithos) excavated in Rethimnon, Crete, Greece, was considered as a substitution stone in a restoration project. In the previous study, 9 the variation of the uniaxial compressive strength, the indirect tensile strength, the intact rock elastic modulus, and the Poisson's ratio versus a critical size (diameter) were presented and critically discussed. However, the complex failure modes of cylindrical specimens under uniaxial compressive loading, in conjunction with the presence of bands in the Alfas porous stone (Figure 1), remain an important subject that should be investigated with respect to the mechanical behavior of this material.…”

Using acoustic emissions to enhance fracture toughness calculations for CCNBD marble specimens

“…Its density is 2.67 g/cm 3 and its absorption coefficient by weight is 0.09%. It is of white color with a few thin parallel ash-green colored veins containing locally silver areas due to the existence of dolomite [12].…”