Zeki Karaca

Recycling waste from natural stone processing plants to stabilise clayey soil

For the countries with a developed stone industry the waste generated in the natural stone processing plants pose environmental and economic problems. The utilisation of stone waste in various areas is still under research. In addition, there are only a limited number of studies concerning the use of stone waste obtained from processing plants in the stabilisation of clayey soil. Furthermore, none of the studies in the literature investigated the effect of the characteristics of the stone on the stabilisation of the soil. This is the first study that compares the efficiency of the waste calcitic marble, dolomitic marble and granite powder as additives for the stabilisation of clayey soil. Artificial soil samples were prepared in the laboratory using bentonite and kaolinite. Natural stone waste powder was added to the soil samples at different percentages, and the index and compaction parameters of the stabilised soil were analysed. The results showed that the types of waste powder used in this study, like lime, could be used as stabilisers. As the percentage of additives increased, the plasticity index of the clayey soil decreased and the physical properties of the soil changed from clay to silt. In terms of compaction parameters, the use of all types of natural waste powder in the study resulted in a decrease in the optimum water content and an increase in the maximum dry unit weight. The lowest optimum water content and the highest maximum dry unit weight were obtained from the dolomitic marble powder.

Classification of dimension stone wastes

PurposeFor countries in which the stone industry is well developed, opposition to quarry and plant waste is gradually increasing. The primary step for waste control and environmental management is to define the problem of concern. In this study, natural building stone wastes were classified for the first time in the literature.MethodsFollowing on-site physical observations and research at more than 50 quarries and 20 plants, stone wastes were classified as (1) solid, (2) dust and (3) semi-slurry, slurry and cake.ConclusionsAs a result of this study, the characteristics of wastes, their main environmental threats and the industries in which wastes could be used were defined for each group.

Biofouling of marbles by oxygenic photosynthetic microorganisms

Phototrophic microorganisms disfigure the surfaces of different types of stone. Stone structure is damaged by the activity of photoautotrophic and other microorganisms. However, to date few, investigations have been undertaken into the relationship between microorganisms and the properties of different types of marble. In this study, biological activity of photoautotrophic microorganisms on three types of marble (Yatagan White, Giallo Anticato and Afyon White) was investigated under laboratory conditions over a short period of time. The three types of marble supported the growth of phototrophic microbial communities on their outer and inner layers, turning their original colour from white to a yellowish green colour. The porosity of the marble types facilitated filamentous microbial growth in the presence of water. Scanning electron microscope analysis revealed the accumulation of aggregates such as small spherical, fibrillar, calcified globular bodies on the inner surfaces of the marbles. This suggests that the microscopic characteristics of particular marble types may stimulate the growth of certain types of microorganisms.

Relationship between Slipperiness and Other Characteristics of Stones used as Flooring Slabs

AbstractSlip resistance is an essential parameter when dimension stones are used as inner and outer floorings. Declaration of performances of stones and their surface finishes (sawn, honed, polished, hammered, flamed, sandblasted, or brushed) in relation to conditions (wet or dry) in Conformite Europeenne (CE) marking is essential for pedestrian safety. In this study, 130 samples taken from 81 stone types belonging to 13 types of petrographic families were tested according to the EN 14231 Standard, taking different finishes into consideration, during a ten-year period in the Marble Laboratory of Politecnico di Torino (Italy). A high number of pendulum friction tests (1,560) were conducted on 780 samples, and more than 7,000 readings were taken. On the basis of the obtained results, significant relations were found between the tested petrographic families and the types of finishes. A high correlation between open porosity, quartz content, and slipperiness of the stones with honed surface finishes was found...