Issue 30

S. Seitl et alii, Frattura ed Integrità Strutturale, 30 (2014) 174-181; DOI: 10.3221/IGF-ESIS.30.23 174 Focussed on: Fracture and Structural Integrity related Issues Wedge splitting test method: quantification of influence of glued marble plates by two-parameter fracture mechanics S. Seitl Academy of Sciences of the Czech Republic, v. v. i., Institute of Physics of Materials, Brno, Czech Republic and Brno University of Technology, Faculty of Civil Engineering, Institute of Structural Mechanics, Brno, Czech Republic seitl@ipm.cz B. Nieto García Academy of Sciences of the Czech Republic, v. v. i., Institute of Physics of Materials, Brno, Czech Republic and University of Oviedo, Department of Construction and Manufacturing Engineering Campus de Viesques, Gijón, Spain UO209943@uniovi.es I. Merta University of Technology Vienna, Faculty of Civil Engineering, Institute of Building Construction and Technology, Vienna, Austria ildiko.merta@tuwien.ac.at A BSTRACT . In the present paper, the well-known wedge splitting test (WST) is applied on specimens with different geometries (S= 150, 200, 300 mm) and variants of the specimens’ configurations. K-calibration ( B 1 ) and T-stress ( B 2 ) calibration curves for such specimens are introduced. The objective was to compare and discuss the values of the calibration curves dependent on the specimen’s geometries and on three different specimens' configurations: homogenous specimen; specimen with marble plates forming the groove for load application and specimen with glued marble plates. K EYWORDS . Wedge splitting test; Stress intensity factor, T-stress; K-calibration curves; Concrete fracture test. I NTRODUCTION he wedge splitting test (WST) is nowadays a popular test for measuring fracture properties of materials like concrete [7, 17, 18, 24]. The WST was developed by Linsbauer and Tschegg [22] and patented by Tschegg in 1986 [30]. A modified WST with different wedge equipment was published by Bruhwiler and Wittmann in 1990 [5]. It is a very stable test for determining the fracture energy of concrete. The specimens used are very compact and require small amounts of material compared to the notched beams employed in three-point bending tests (3PBT). However, the implementation of this type of test requires more sophisticated tools than the 3PBT and the number of experimental results available in the literature obtained using the WST of concrete is very limited. Calibration curves for the WST are not as widely reported. Stress intensity factors (SIF, K-factor) for particular variants of the WST (cube-shaped specimens) can be found in the literature, e.g. Guinea et al. [10]. K and T-stress calibration curves for foam concrete with marble plates forming the rectangular groove on the upper side of WST specimens are presented in [29]. Multi-parameter T