Dimension stone is a valuable mineral raw material whose importance is increasing worldwide. According to its mineralogical and petrographical composition, Croatian dimension stone belongs to the carbonates, primarily limestones. As saturation influences the reduction of compressive strength, in this study, the relationship between the uniaxial compressive strength in the dry and saturated states is shown, which has a coefficient of determination of 0.9605. Models were created to estimate the compressive strength based on the values of water absorption, total porosity, and real density of the material from 26 sites, all determined according to the European standards EN 1936:2006 and EN 13755:2008. Thirty varieties of dimension stones were tested, and 150 values were collected from different tests. A dependence between the uniaxial compressive strength in the saturated state was established, including the explanation in which cases the correlation can be used to estimate the uniaxial compressive strength of carbonate dimension stones with a remarkably high degree of confidence (0.994 and 0.9374). In addition, the limitations of geomechanical estimation of the uniaxial compressive strength of rock material and its unsuitability for estimating of dimension stones construction are described.

Geological investigations were carried out in the Sinawin-Sha'wa area, in northwestern Libya, in order to find suitable rocks for aggregate in asphalt mixtures for Nalut - Ghadamis Road reconstruction. By combined field work and micropetrographical analysis four different carbonate lithofacies were determined within Upper Cretaceous sedimentary sequence: lithofacies A - micritic limestones; lithofacies B - dolomitic marls; lithofacies C - dolobiomicrites; lithofacies D -biosparites and biosparudites. Diagenetic processes of cementation, recrystallization, dolomitization and silicification were identified within these lithofacies. Stone samples, taken from three lithofacies A, C, and D, were analyzed in order to determine its physical and mechanical properties (apparent density, open porosity, water absorption, uniaxial compressive strength). In addition, aggregate produced by crushing of the rock from lithofacies D is tested on resistance to crushing and abrasion (LA test). Samples from lithofacies B were not included in the testing of physical and mechanical properties since it is estimated as not suitable rock material for crushed aggregate. Samples from lithofacies A, C and D showed significant differences in the physical and mechanical properties. These differences stem from differences in mineralogical and petrographical composition as well as from diagenetic processes. Stone of lithofacies D were estimated as the most appropriate rocks available in the area, for aggregate in asphalt mixtures.

Crushed stone is one of the most exploited and important mineral raw material. Emphasis is given to determination of mineralogical and petrographic properties, of two genetically different rocks of silicate composition, commonly used as crushed stone for road constructions, as their physical properties depend on them. First is amphibolite from Vetovo, and second is basalt from Vratnik locality, both sourced from Croatia. Tests conducted according to European and Croatian norms evaluated the real and apparent density, open and total porosity, and water absorption of stones. The relationship between mineralogical and physical properties led to the following conclusions: the open porosity values of amphibolite samples are low, which is a consequence of the medium to high degree of metamorphism, (plagioclase and hornblenda), sosiritization, and undisturbed rock features. The total water saturation was achieved in a brief time, confirming this statement. The basalts have different porosity and water absorption values, which are consequences of differences their textural-structural properties (glassy, intersertal or intergranular groundmass), amount of amygdules, presence or absence of chlorite/volcanic glass. Furthermore, the percentage of plagioclase in the modal composition differs, and the plagioclase itself has been altered, and the amount of clay, sericite and calcite vary in two different varieties of basalt. Compared to amphibolites, basalts have notably higher water absorption values as well. Accordingly, the studied amphibolite has water absorption less than 0.5% and is suitable for use in a road construction application for wearing course in the asphalt pavement, and studied basalt is not.

Purpose. This paper aims to show the petrographic microstructural properties of natural stone as a building material from Benkovac, which is exposed to the influence of sea salt crystallization on the Croatian Adriatic coast. Methods. The research is based on the graphical and statistical analysis of the results of polarization and electron microscopy, resistance to salt crystallization, ultrasound propagation velocity and uniaxial compressive strength testing. Three diffe-rent lithotypes of limestone – grainy, micritic and laminated are analyzed to evaluate their important petrographic properties that have impact on the durability when material is exposed to the salt crystallization. Findings. In the petrographic analysis, different characteristics are highlighted, especially those relevant to anisotropy of the structural features as lamination or layering. Besides determination of resistance to the salt crystallization, propagation of ultrasound direct P waves and uniaxial compressive strength are also tested. It is of scientific importance that a change in the internal structure of all samples, especially the laminated lithotype, is observed during the testing. The decrease of ultrasonic propagation velocity, decrease in compressive strength, and durability due to the action of crystallization pressure is a result of increase of the pore space and the fracturing along natural discontinuities such as lamination and layering. Originality. This paper is the first to deal with the resistance to salt crystallization of the Benkovac stone, especially from the point of view of its petrographic properties. It also deals with the new aspect of interpreting the durability results by combining different methods of evaluating properties that are related to each other. Practical implications. The knowledge gained in a specific area of the thin-bedded limestone of Benkovac can also be utilized in other places for better and effective protection and preservation of buildings, for which the same type of stone is quarried and used in construction.