Abstract The paper outlines the physical parameters and textural differences of clay marl, marl, and calcareous marl, focusing on the physical changes that are caused by water. The characterization of marls is often very difficult since their properties are variable, covering a broad range from low-strength friable rock to highly cemented durable lithologies. Consequently, the prediction of their physical parameters requires further consideration. The paper addresses this issue by physically and texturally characterizing Eocene marly lithologies and comparing their properties to various limestones. Density, water absorption, ultrasonic pulse velocity, uniaxial compressive strength (UCS), Brazilian tensile strength, Young’s modulus, and their interdependencies are explained. The link between physical properties and various micro-fabrics is also outlined, with the help of new equations. Our tests show that UCS of calcareous marl can be as high as 100 MPa, but it decreases when the sample is water saturated. Relationships were calculated between the physical parameters of air-dry and water-saturated samples. Correlations between Young’s moduli and uniaxial compressive strength are also explained. The results of our analyses were compared to published physical parameters of marls and limestone, and relationships were outlined between the parameters of these carbonates.

Abstract Salt crystallization is a major agent of deterioration in natural stones used in architectural and geotechnical applications. This study evaluated the resistance of four travertine types—Kütahya Red (KRT), Emirdağ Silver (EST), Antalya Noche (ANT), and Karaman Light (KLT)—to salt-induced weathering under controlled laboratory conditions. A comprehensive experimental program was implemented, including physical and mechanical characterization, chemical and mineralogical analyses (XRF, XRD), petrographic examination, and scanning electron microscopy (SEM). Salt crystallization tests were conducted over 15 cycles using Na₂SO₄·10 H₂O, MgSO₄·7 H₂O, NaCl, and KCl solutions. The results indicate that Na₂SO₄ produced the most severe deterioration, particularly in the EST and KLT samples, owing to the high crystallization pressures associated with phase transitions. MgSO₄ induced moderate damage, whereas NaCl and KCl caused limited surface alteration and internal degradation. ANT exhibited the highest resistance, retaining its mechanical strength, low porosity variation, and structural integrity across all salt exposures. In contrast, the EST and KLT experienced marked reductions in real density, ultrasonic velocity, and uniaxial compressive strength, along with increased water absorption and microcrack formation. Despite its initially dense structure, KRT displayed moderate susceptibility to sulfate salts. SEM analysis confirmed salt crystallization within the pore networks and the development of microcracks, particularly in the highly porous samples. These findings emphasize the influence of pore structure, mineralogy, and salt type on the durability of travertine. The results offer practical guidance for the selection and conservation of travertine stones in engineering and architectural settings that are exposed to saline environments.