Petrographic, physical and mechanical properties of serpentinite varieties from Ljeskovac locality, Croatia
摘要
Due to their unique aesthetic and functional properties, serpentinites are considered valuable natural materials in construction and architecture. Although present in some parts of Croatia, serpentinites did not attract significant attention of researchers in the aspect of application. Our work presents first compilation of the results dealing with petrographic, physical and mechanical properties of serpentinites from the Ljeskovac locality (Croatia). Two varieties are identified: serpentinites and serpentinite breccia. The main petrographic difference is carbonate content, which is much higher in the serpentinite breccia (up to 73.47%), where it acts as cement holding serpentinite fragments. Textural elements such as open and filled cracks, carbonate cement and serpentinite fragments contributed to much higher textural heterogeneity in serpentinite breccias. Serpentinites have higher real and apparent density (2739 and 2579 kg/m3) then serpentinite breccias (2659 and 2469 kg/m3). Open porosity reaches up to 7.76% and 8.54%; water absorption 3.20% and 3.54%; water desorption 2.29% and 2.46%; point load strength index (PLSI) 3.12 and 1.99 MPa; Leeb rebound hardness (LRH) 749.20 and 685.80; Schmidt rebound hardness max values are 39.70 and 32.46 in serpentinites and serpentinite breccias respectively. The interdependence of aesthetic and physical properties is best observed in the ratio between serpentinite fragments and carbonate cement in the serpentinite breccia. Carbonate cement is shown to have a positive effect on the PLSI. The overall properties of the Ljeskovac serpentinites suggest that this material is not suitable for utilisation, directing further research towards the direction of refinement of these varieties.