Investigation of Mechanical Properties of Kofke Stone Used in Historical Buildings in Isparta by Nondestructive and Destructive Methods

Abstract

Abstract The seismic behavior of historical buildings and possible damages that may occur in the structure can be determined by software such as finite element models. However, for an accurate simulation, the properties of masonry building materials should be determined with high precision. In many cases, it is inconvenient to conduct experiments that may destroy historical structures. Therefore, non-destructive methods are also needed to determine material properties. In this study, the mechanical properties of Köfke stone used in historical masonry buildings in Isparta province, many of which are still actively used, were investigated. Non-destructive and destructive methods were used in the investigation and these methods were correlated with each other. In the study, properties of kofke stone such as dry-unit volume mass, porosity, water absorption by mass, ultrasonic seismic velocity, Schmidt tensile strength, dynamic modulus of elasticity, compressive strength, splitting-tensile strength, static modulus of elasticity were determined. All tests were performed by the applicable national and international standards. The dry unit volume mass of Kofke stone is 1434 kg/m3, water absorption by mass is 18.5%, longitudinal seismic wave velocity (avg.) was 1806 m/s, Schmidt hammer strength was 17.6 MPa, dynamic modulus of elasticity was 4.85 GPa and Poisson's ratio was 0.19. In the destructive tests, the compressive strength was determined as 6.57 MPa, the splitting-tensile strength as 0.71 MPa, and the modulus of elasticity as 1.66 GPa. Empirical equations for the prediction of the compressive strength and static modulus of elasticity of kofke stone by non-destructive methods were also presented.