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This paper brings a comprehensive review of the main petrophysical and mechanical properties of calcarenite rocks used from time immemorial in Apulia (south Italy), with loadbearing and decorative functions both in constructions of specific historic and architectonic interest and in more common buildings. These soft and porous rocks show a reduced ability to maintain their characteristics of strength, appearance and resistance to decay over a considerable period of time. Even more than other sedimentary rocks, calcarenites belonging to the same formation can change considerably in terms of physical properties and mechanical behaviour due to the complex spatial arrangement of facies strongly conditioned by depositional fabric and diagenetic processes. A number of calcarenite varieties belonging to the Calcarenite di Gravina Fm. and Pietra Leccese Fm. was selected from different parts of Apulia and characterized according to petrographical, physical and mechanical properties. These included porosity, pore size distribution, density, water absorption, degree of saturation, permeability, thermal properties as well as compressive strength and flexural strength. Particular attention was given to the relationships between rock fabric features and physico-mechanical behaviour of the calcarenites. In addition, a comparison of data for the examined varieties was also discussed. A classification of the Apulian calcarenites based on rock fabric features and uniaxial compressive strength was proposed. Critical observations regarding the durability of the Apulian calcarenites were made, taking into account other data from literature.

The results of a study of the effect of marine salt crystallization on the physical and mechanical properties of Plio-Pleistocene calcarenites cropping out in southern Italy are presented here. Owing to their workability, aesthetic appeal and availability, the calcarenites have been widely used as building stones in many historic monuments. Samples of medium-grained packstones and fine-grained packstones-wackestones were prepared for the salt crystallization test defined by EN 12370, using sea water instead of a 14% solution of Na2SO4 · 10H2O. To determine the effect of imbibition alone on the performance of the calcarenites, the same procedure was followed with distilled water without soluble salts. Microfabric analysis, evaluation of index parameters and grain-size distribution were carried out as well. Particular attention was given to pore-size distribution by mercury intrusion porosimetry (MIP), loss of weight and uniaxial compressive strength determined before and after the tests, and after every five cycles of complete immersion in sea water and distilled water. The results suggest that detailed information on fabric and pore network are indispensable to predicting the weatherability of rocks. Crystallization tests that involve the complete immersion of the samples in a saline solution are not effective for an understanding of the real importance of salt damage on soft and porous calcarenites owing to a significant incidence of imbibition in accelerating deterioration rates and in influencing patterns and intensity of weathering.

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The purpose of the study was to determine the properties influencing the performance of Apulian calcarenites as past and present building and ornamental stone. A comparison of qualitative fabric observations in petrographic thin sections and quantitative measurements of physical properties, including porosity, pore size distribution and permeability, is discussed. The results suggest that the mercury intrusion porosimetry data and qualitative fabric analysis related to pore size distribution are the most critical observations regarding the potential for the stone to take in and hold water and hence to weather.Résumé Le but de cette étude était a été de déterminer les propriétés des calcarénites de l'Apulie, favorables à leur utilisation comme pierres de construction et pierres ornementales. Des observations qualitatives de la texture à partir de lames minces et des mesures quantitatives de propriétés physiques, incluant porosité, courbe porosimétrique et perméabilité, sont comparées et discutées. Les résultats suggèrent que les données issues de la porosimétrie au mercure et de l'analyse quantitative de la texture en rapport avec la courbe porosimétrique du matériau constituent les paramètres les plus adéquats permettant de caractériser l'aptitude de ces matériaux à absorber et retenir l'eau et donc leur altérabilité.

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This paper deals with the effects of thermal stresses on selected carbonate rocks used as dimension stones. They are Mesozoic calcareous and dolomitic rocks cropping out in Apulia (southern Italy) that, for their physico-mechanical and aesthetic properties, have always been finding a large application both as ornamental stones and as simple construction materials; their use is attested not only in Italy, in works of archaeological, historical and artistic interest too. The cause–effect relationships of thermal degradation were studied by means of an artificial accelerated ageing test, in order to provide a perspective about the decay of carbonate stones due to diurnal and seasonal temperature fluctuations, as well as thermal shocks during events of fire development. The stone samples were subjected to thermal cycles in a muffle furnace, ranging from 100 to 700 °C; after each cycle, several non-destructive and semi-destructive tests were carried out: mass and volume measurements, mercury intrusion porosimetry, sclerometer tests, ultrasonic tests, thin-section observations and determination of chromatic alterations through image analysis and Munsell charts method. In this way, the qualitative and quantitative modifications induced in fabric, physical and mechanical properties were discussed. The results highlight the fundamental role of depositional and diagenetic fabric that, together with mineralogical composition, represents the most significant discriminating factor in the response of the stone to thermal stresses