Natural Stone Products Research Articles

ДОСЛІДЖЕННЯ ВПЛИВУ СПОСОБУ ОБРОБКИ НА АДГЕЗІЙНУ ЗДАТНІСТЬ МОНТАЖНИХ ПОВЕРХОНЬ ВИРОБІВ З ПРИРОДНОГО КАМЕНЮ

Purpose. The purpose of the research is to establish the degree of influence of the structural-textural features and the method of processing the facing surface of natural stone products on their ability to adhere. Methodology. To achieve the goal of the research, the following steps were taken: justification and formulation of the hypothesis regarding the dependence of adhesion on the parameters of micro-relief of stone products and the structural-textural features of rock formations; determination and description of the requirements for the samples under investigation; review and brief characterization of the typology of fixing mixtures; selection and description of the main parameters of the mounting surface (base) for fixing the samples under investigation; development of a sequential plan for conducting the research part of the work; actual execution of the research; analysis of the obtained results. Results. Based on the results of the research, the influence of the method of processing the mounting surfaces of stone products on the magnitude of the provided adhesive interaction and the influence of the structural-textural features of natural stone on the adhesion magnitude of adhesive interaction have been established. Scientific novelty. The scientific novelty lies in establishing the relationship between the ability of the surface of natural stone to adhere and the method of its processing; for the first time, the value of adhesion magnitude for the sawn texture of granite from the Didkovytske deposit and gabbro from the Kamyanobridsky deposit has been determined. Practical significance. The practical significance of the obtained results lies in the possibility of using the obtained dependencies for the early prediction of the adhesion magnitude of the surface of facing products made of natural stone to the surface to which they are attached, based on the physical-mechanical properties of the stone and the method of processing its surface. Keywords: adhesion, natural stone, diamond wire sawing, disk sawing, stone product installation.

Guidelines for Natural Stone Products in Connection with European Standards.

The selection of ornamental stones for specific applications requires technical guidance since it should be based on the durability, service life, and aesthetic value of the stones. In most cases, these fundamentals provide quantitative data on the usability and performance of ornamental stones. The present study attempts to put forward a quantitative classification system for natural stone products concerning critical rock properties. For this purpose, fundamental physical and mechanical rock properties are listed based on European standards. Then, minimum limit values are proposed for different applications of natural stone products based on retrospective analyses of numerous ornamental stone applications. The suggested limit values based on several physical and mechanical rock properties can guide relevant engineers to initially consider possible rock types for use as natural stones in a wide range of applications. In this context, it is believed that the present study contributes to the natural stone industry by discussing the minimum limit values for the consideration of a wide range of rock types possibly usable in the dimension stone industry.

ОГЛЯД ПЕРСПЕКТИВ ЗАСТОСУВАННЯ СМУГ ВИГОТОВЛЕНИХ ЗА ТЕХНОЛОГІЄЮ FIBERGLASS ДЛЯ АРМУВАННЯ АРХІТЕКРУРНО-ДЕКОРАТИВНИХ ВИРОБІВ З ПРИРОДНОГО КАМЕНЮ

Purpose. The purpose of this study is to assess the feasibility of using fiberglass strips manufactured with technology for reinforcing architectural decorative products made of natural stone by comparing their strength properties and behavior under bending strength. Methodology. The preparation of samples for strength testing has been carried out, and recommendations regarding the process have been described. Recommendations have been provided regarding the preparation, configuration, and implementation of the main tools and materials involved in the course of the research. Components of the experiment aimed at determining the strength characteristics of the samples have been developed and described. In accordance with the set tasks and the array of data obtained empirically, numerical values of the strength characteristics of natural stone products under external loads have been calculated. The calculations are performed in accordance with the general principles of theoretical and applied mechanics. Results. The influence of reinforcement on the strength of stone has been studied, expanding existing theoretical knowledge about the strength properties of stone and the possibilities for their improvement. New theoretical models and methods for assessing the strength characteristics of stone, taking into account the influence of reinforcing elements, have been developed, contributing to a deeper understanding of the processes occurring in the structure of stone during reinforcement. Scientific novelty. The existing methods of reinforcing natural stone products have been systematized and reviewed, and the ways to optimize them using modern composite material manufactured with fiberglass technology have been suggested. The feasibility of applying internal reinforcement technology to enhance the strength properties of natural stone products has been substantiated. For the first time, the methodology and effectiveness of applying internal reinforcement manufactured with fiberglass technology to improve the strength properties of products from the Pokostiv deposit granodiorite have been analyzed. Practical significance. The practical importance of the obtained results lies in the opportunity to transform theoretical knowledge into practical recommendations for improving the technology of manufacturing products from natural stone to enhance their reliability in operation and simplify the manufacturing process.

Characterization of the Emissions and Crystalline Silica Content of Airborne Dust Generated from Grinding Natural and Engineered Stones.

In this study, we systematically characterized the airborne dust generated from grinding engineered and natural stone products using a laboratory testing system designed and operated to collect representative respirable dust samples. Four stone samples tested included two engineered stones consisting of crystalline silica in a polyester resin matrix (formulations differed with Stones A having up to 90wt% crystalline silica and Stone B up to 50wt% crystalline silica), an engineered stone consisting of recycled glass in a cement matrix (Stone C), and a granite. Aerosol samples were collected by respirable dust samplers, total dust samplers, and a Micro-Orifice Uniform Deposit Impactor. Aerosol samples were analyzed by gravimetric analysis and x-ray diffraction to determine dust generation rates, crystalline silica generation rates, and crystalline silica content. Additionally, bulk dust settled on the floor of the testing system was analyzed for crystalline silica content. Real-time particle size distributions were measured using an Aerodynamic Particle Sizer. All stone types generated similar trimodal lognormal number-weighted particle size distributions during grinding with the most prominent mode at an aerodynamic diameter of about 2.0-2.3 μm, suggesting dust formation from grinding different stones is similar. Bulk dust from Stone C contained no crystalline silica. Bulk dust from Stone A, Stone B, and granite contained 60, 23, and 30wt% crystalline silica, respectively. In Stones A and B, the cristobalite form of crystalline silica was more plentiful than the quartz form. Only the quartz form was detected in granite. The bulk dust, respirable dust, and total dust for each stone had comparable amounts of crystalline silica, suggesting that crystalline silica content in the bulk dust could be representative of that in respirable dust generated during grinding. Granite generated more dust per unit volume of material removed than the engineered stones, which all had similar normalized dust generation rates. Stone A had the highest normalized generation rates of crystalline silica, followed by granite, Stone B, and Stone C (no crystalline silica), which likely leads to the same trend of respirable crystalline silica (RCS) exposure when working with these different stones. Manufacturing and adoption of engineered stone products with formulations such as Stone B or Stone C could potentially lower or eliminate RCS exposure risks. Combining all the effects of dust generation rate, size-dependent silica content, and respirable fraction, the highest normalized generation rate of RCS consistently occurs at 3.2-5.6 µm for all the stones containing crystalline silica. Therefore, removing particles in this size range near the generation sources should be prioritized when developing engineering control measures.

ДОСЛІДЖЕННЯ ДОЦІЛЬНОСТІ ЗАСТОСУВАННЯ СКЛОПЛАСТИКОВИХ ТА БАЗАЛЬТОПЛАСТИКОВИХ СТЕРЖНІВ ДЛЯ АРМУВАННЯ ВИРОБІВ З КАМЕНЮ

Purpose. The purpose of this work is to study the feasibility of using different types of composite materials for natural stone products reinforcement by comparing their strength characteristics. Methodology. Recommendations for the preparation of samples for strength research have been implemented and described. Recommendations for the preparation, adjustment and commissioning of fixed assets and materials used in the study are given. The constituent elements of the experiment aimed at determining the strength characteristics of the samples are developed and described. Based on the results of the obtained data, the values of the basic strength parameters during the destruction of the samples under the action of bending loads have been calculated. Results. The study of the technology of stone products reinforcement allows solving a number of problems related to improving the quality and competitiveness of stone manufacturing. A holistic and scientifically sound study of reinforcement technology allows an array of empirical data and developing the optimal order of its use. Scientific novelty. Systematization and review of existing methods of natural stone products reinforcement are performed and methods of their optimization with the help of modern composite materials are offered. The expediency of using fiberglass and basalt-plastic composite materials for the purpose of reinforcing stone products has been empirically investigated. The expediency of using fiberglass and basalt-plastic composite materials for natural stone products reinforcement by comparing the obtained values of strength characteristics has been substantiated. Practical significance. The practical significance of the obtained results lies in the possibility of their application in order to simplify, modernize and improve the technology of stone products reinforcement for its widespread introduction as one of the basic technologies in the conditions of stone processing enterprises. However, the research results confirm the fact of the expediency of using composite reinforcement (especially basalt-plastic) to improve the strength properties of stone products.

ЗАСТОСУВАННЯ КОМПОЗИТНИХ МАТЕРІАЛІВ ДЛЯ АРМУВАННЯ АРХІТЕКТУРНО-БУДІВЕЛЬНИХ ВИРОБІВ З КАМЕНЮ

Purpose. The purpose of this work is to generalize the main aspects of the natural stone products’ reinforcement technology and to establish tendencies in the strength characteristics of these products. Methodology. The degree of relevance of the researched topic is established, the general characteristic of reinforcement as a technological process is given and the work on the given subject is analyzed. Recommendations for the preparation of samples for performance studies of strength characteristics are implemented and described. Recommendations on the selection and features of the use of tools for cutting, reinforcing elements and fixing mixture are given. The constituent elements of the experiment aimed at determining the strength characteristics of the samples are developed and described. Based on the results of the received data, the calculation of the values of the basic strength parameters during the destruction of the samples under the action of bending loads is performed. Results. Research of technology of reinforcement of products from a natural stone allows solving a number of problems on a way to improve the quality and competitiveness of production of the stone processing enterprises. A holistic and scientifically substantiated description of the reinforcement technology allows to systematize the knowledge about this technology and standardize the optimal order of its use, as well as to provide grounds for further study of its main technological aspects. In addition, the concomitant experimental establishment of improving the strength parameters of products as a result of their reinforcement proves the actual benefits of using this technology to improve the strength characteristics of the final natural stone product. Scientific novelty. The algorithm of using the technology of reinforcing natural stone with composite materials with indication of the peculiarities of this process is investigated, systematized and described. The degree of change in the strength characteristics of products as a result of their reinforcement is studied empirically. The expediency of using the technology of natural stone products reinforcement by comparing the strength properties of reinforced and non-reinforced products is substantiated. Scientific significance. The practical significance of the obtained results is embodied in the possibility of their use for the development of methodological and specific statutory guidelines for the introduction of reinforcement technology under the conditions of stone processing enterprises and for further research to optimize the described technological processes. At the same time, the results of the study of the strength parameters of composite elements reinforced with natural stone products are the firm argument that proves the feasibility of industrial use of this technology.

Pengembangan Produk Unggulan Daerah Berorientasi Ekspor Pada Industri Kerajinan Batu Alam Nusa Tenggara Timur

Regional superior products in NTT Province are currently the main pillars of the people's economy. Through the development program of superior products of export-oriented regions in the natural stone handicraft industry in UD Pesona Batu Alam, it is able to increase productivity, turnover and other assets. The support of Kupang State Polytechnic through the improvement of innovation-based mechanization on the types and kinds of production needed by the community through craftsmen in UD. Pesona Batu Alam is very necessary. Measured activities include the development of rock type designs through a variety of forms to attract tastes of domestic and foreign customers. The implementation methods that are carried out include the manufacture and application of cutting tool technology and portable stone grading screw systems to be part of the innovation targeted in this service program. The characteristics of the tool are designed in accordance with the conditions of natural stone and NTT Province's distinctive limestone products. The results of this service program are able to improve the quality of products, including the use of by-products in addition to being able to stimulate sales and marketing between islands and between neighboring countries.

EVALUATION OF THE EFFECTIVENESS OF NATURAL STONE SURFACE TREATMENT FROM UKRAINE BY MECHANICAL AND CHEMICAL METHODS

Studies have been conducted with the aim of studying ways to improve the decorative properties of natural stone products. That will allow to make finished product run of natural stone with a homogeneous tint. For this purpose, the indicators of luster, lightness and saturation of natural surfaces of facing stone worked by mechanical and chemical methods are described. The influence of chemical treatment on the decorative indicators of various kinds of natural facing stone depending on its mineralogical composition is determined.

Interaction of paint materials with a surface of natural stone

Anthropogenic activity causes air pollution and is one of the main factors responsible for the disintegration of archaeological and historical stone monuments. Over the past two centuries there has been a rapid increase in the rate of disintegration of stone monuments, especially in European and North American countries. The main reason for this was the legacy of anthropogenic activity, which is associated with the industrial revolution. Previously, natural stone products also underwent some changes in characteristics, but in another time scale, i.e., the geological time scale. The development of industry, the expansion and concentration of urban landscape have led to accelerated decay processes. Lately, graffiti has become widespread, which can also seriously damage the stone materials and lead to material losses and even loss of value. The article performs the evaluation of the harmful effects of permanent markers on the facing of natural stone. The Pokostivsky, Korninsky, Kapustinskaya, Mezhirichinskaya deposits of natural stone are studied. The boundary angles of spreading the paint on the alcoholic and aqueous basis on the polished surface of the stone were determined. We also measured the dispersion angles of surface for water. As a result of the research, the hydrophobicity of the polished surface of a natural stone was discovered. The amount of paint penetration after its application on a stone is established. It has been found out that the spread depends on the colour of the paint.

Natural Stone in Spain: trends and perspectives

The natural stone sector was severely affected by the national construction sector crisis. Production, both ex-works and processed, has been also harshly affected dropping from 8Mt/y in 2007 to 3,49Mt/y in 2015, particularly in the marble and granite sectors, since slate has always been a mainly exporting sub-sector. In the latest times, thanks mainly to exports, production apparently has slowly started to recover. In this paper, we review the typology of the Spanish natural stone products and the production data of the main stone sub-sectors (marble, granite and slate) in the last 10 years and we review possible future trends in the framework of the first steps of the economic recovery.

Algorithmic compensation of video image dynamic errors with measurement data about geometric and object motion parameters

Abstract This article considers the mathematical models and methods of identifying the video image dynamic errors. These movies contain information on measuring the geometric parameters and motion parameters of natural stone products and equipment used in their manufacture. The details of dynamic errors are required to develop the algorithmic procedures of their compensation and to improve the accuracy of measuring these geometrical and motion parameters of the measurement object.

Definition of hue of different types of pokostivskiy granodiorite using digital image processing

An important task of stone processing enterprises is decorativeness management of natural stone products. Among different ways to change the natural stone decorativeness parameters, stone polishing is the most common.Classification of the types of Pokostivskiy granodiorite of different hues is based on the characteristics of different types of stone after machining. However, information about the original color characteristics of stone blocks is needed for selecting the polishing technology. In the study of Pokostivskiy granodiorite blocks, the patterns of lightness changes in rough and polished samples of the types of Pokostivskiy granodiorite of different hues depending on the share of white minerals were identified. Before polishing, lightness and average share of white minerals for light, dark and very dark types of Pokostivskiy granodiorite are virtually unchanged. After polishing, lightness of different types of Pokostivskiy granodiorite changes respectively from 59.5 % to 69.4 % – for light types; from 59.0 % to 65.5 % – for dark types; from 58.8 % to 61.2 % – for very dark types.The developed method of determining the types of Pokostivskiy granodiorite of different hues using digital image processing will allow distinguishing rough blocks, different in lightness and hue, on stone processing enterprises. This will enable stone processing enterprises to select raw materials without prior processing and to choose the polishing technology for standardized products that are made of similar rocks.

Valorization of Phosphate Waste Rocks and Sludge from the Moroccan Phosphate Mines: Challenges and Perspectives

Sedimentary phosphate mines produce millions of tons of waste rocks during their open-pit mining. In addition, during ore phosphate beneficiation, fluorapatite is separated from associated gangue minerals by a combination of successive mineral processing steps that involve crushing / screening, washing, and flotation. These operations generate large volume of tailings (called phosphate sludge) that are deposited in large surface ponds and waste rocks stockpiled within the mining site. The potential reuse of these phosphate mine by-products (waste rocks and sludge) has been investigated in the last 10 years.The first investigated option consisted in using the alkaline waste rocks (APW) to control the acid mine drainage (AMD). Indeed, these alkaline mine wastes contain significant quantities of calcite (46 wt%) and dolomite (16 wt%) that help in neutralizing the acidity generated by the wastes from the closed Kettara mine, located near Marrakech, Morocco. The addition of 15 wt% APW to the coarse Kettara tailings produced leachates with significantly lower acidity and metal loads in comparison to the un-amended control sample. Secondly, the efficiency of APW was assessed in the laboratory as an alternative alkaline material for passive AMD water treatment. In semi-arid climate, the oxic passive treatment has been proven to be the most suitable. The pH of the water and its quality were significantly improved. As a third option, the hydrogeotechnical characterization of original and screened phosphate limestone waste rocks as well as the phosphate sludge showed their suitability for use as a component of store-and-release (SR) covers for industrial mine site reclamation. Lab tests (columns) and field tests (instrumented columns and experimental cells) showed that water infiltration can be controlled, even for extreme rainfall events (150mm/day), by 1 m thick of a SR cover made with APW. Further research is currently being investigated around the recycling and valorization of phosphate sludge from phosphate mines as ceramics. Furthermore, the overburden of the phosphates sedimentary basins are mainly composed of marls; limestones blocks; silex bed; silex nodule; marls and clays; silicified limestone; which have a significant reuse potential as marble-mosaic floor, mortars and concrete, and natural stone products slabs for floors and stairs.

Mesozoic carbonate rocks in Serbia used as dimension stone

The building industry in Serbia uses, to a great extent, imported natural stone for architectural purposes. The significance of local deposits, particularly limestones, is not adequately perceived despite the country’s abundance of these valuable resources. Therefore, this study focuses on Serbia’s Mesozoic carbonate rocks, specifically on the deposits of four selected quarries: Klisura, Skrzut, Struganik, and Tisnica. The quality and prospects of the application of these limestones has not yet been the subject of a detailed, comprehensive investigation. Therefore, this research is primarily concerned with the examination of their petrological and physico-mechanical properties in order to propose their scope of application further as dimension stone. According to the petrological features, different carbonate microfacies are observed: biolithites, pure orthochemical micrites, allochemmicrites, and allochemsparites. Physico-mechanical characteristics confirmed that the investigated carbonate rocks are of high bulk density, compact or of low porosity, of very low water absorption, hard, and with high to moderately high values of compressive strength. The scope of use is established according to a comparison of statically analysed engineering properties with the technical requirements necessary for a suitable reference of natural stone products. The results demonstrate that the examined rocks are suitable for use as slabs for architectural cladding and paving, whereas the occurrence of bedding and occasional tectonic fissures (fractures) is considered to be a limiting factor of exploitation.

Influence of grinding-polishing of natural stone on its shine and lightness shades

An important problem of stone processing enterprises is decorativeness control of natural stone products. Among many different methods that allow to change natural stone decorativeness parameters, textured surface finishing is the most common. In the study of products from Pokostivske granodiorite, color and lightness classification was proposed. Depending on the stone surface roughness, a change in the stone lightness and shine was investigated. Using the fine-grained diamond tool, stone sample darkening is achieved by reducing the stone surface roughness. Stone lightness can be adjusted to ensure minimum differences in their future use. Ensuring minimum differences of the polished stone surface is possible for species with the same color and adjusted for a stone with red and blue color (from light to dark); for a stone with blue color (from dark to very dark). In the future, it is important to solve the problem of labeling different types of blocks that will ensure their recognition and selection of the grinding-polishing procedure to provide the desired lightness shade.

"Schist" from Trás-os-Montes and Alto Douro (NE of Portugal): Potential Use as Natural Stone

The main purpose of this work was to increase the knowledge about the geological resources of Trás-os-Montes and Alto Douro region (TMAD), particularly about their “schists” (slate, phyllite and schist), due to the economic and social effects that their mining and processing can have, not only on the local economy, but also on a national level. This work presents the results of the study conducted on “schists” from TMAD, aiming for their use as natural stone. Special emphasis is given on the results obtained from the following physical and mechanical tests: compressive strength, flexural strength, apparent density, open porosity, water absorption, abrasion resistance and resistance to ageing by thermal shock. These tests were determinant to define the most suitable applications for each schistose stone that was studied, taking into account the existing groups of natural stone products. For defining the recommended applications for each “schist”, European standards for natural stone products were considered, as well as technical specifications that exist in some European countries, which were the basis for the establishment of a proposal of technical specifications for Portugal, already published by one of the authors of this work.

An Investigation of Colour Properties of Orosei Limestones (Italy) by Using Computer Program

In this study, a new computer program developed to determine the colour properties of natural stone products is introduced. The program can scan any digitalised picture of natural stone products and produce several statistical results such as mean, variance, minimum and maximum colour values, skewness and kurtosis values of the colour histogram, energy, contrast, entropy and homogeneity values of the data which may be used to classify the typology and/or quality of natural stone products. As a case study, Orosei limestones (Sardegna, Italy) were used. There are several typologies of Orosei limestones such as Nuvolato (Cloudy), Venato chiaro (Light veined), Venato medio (Medium veined), Venato scuro (Dark veined), Perlato chiaro (Light pearled), Perlato medio (Medium pearled) and Perlato scuro (Dark pearled). The remarkable results produced by the program are presented.

Mineral inlays in natural stone slabs: techniques, materials and preservation

Italy (first) and Spain (second) are the largest producers of marble in the world, and they share a rich history of quarrying and artworks made from natural stone and coloured stones inlaid in marbles. The present decrease of manufactured marble from Spain and Italy is directly related to the increased imports of high quality manufactured natural stone products from Asian countries. Indian stone products are following classic Florentine patterns coupled with modern uses of resins and heavy machinery. Historic lapidary remains of marbles, rocks and semi-precious stones inlaid in tables displayed in the Prado Museum (Madrid, Spain) have been analysed by X-ray diffraction and microscopy using optical lens with guide lights (in situ samples), polarising and scanning-EDAX microscopes. The Florentine table studied has approximately 8000 pieces; however, they belong to a small number of mineralogical species such as quartz, perthite–feldspar, olivine, garnet, sodalite, haüyne, nosean, pyrite, beryl, chrocidolite, chrysotile, malachite, variscite, etc. The classic stone-cutting techniques were analysed through the study of the historic Gasco hydraulic sawmill, which is well preserved and composed of a dam, canal, waterwheel, well, saw room, external workshops and refuse dump (containing the remains of cut marbles, screws, iron fragments, iron balls, etc.). Decolourisation and phase transition tests of stones were carried out using an original self-simultaneous optical stimulation and X-ray diffraction (SOSXRD) system.

THE WITHA HILL BUILDING STONE QUARRIES AT LANGHOLM, SCOTTISH BORDERS - ENVIRONMENTAL GEOLOGY AND HISTORICAL ASPECTS.

Keywords WREXHAM COUNTY BOROUGH COUNCIL MATERIALS, CONSTRUCTION, BUILDING, STONE, QUARRIES, ENVIRONMENTAL, GEOLOGY, HISTORY, SANDSTONE, ASHLAR, BLOCKS, WALLS, NATURAL, PRODUCTS, WHITA SANDSTONE, EARLY, CARBONIFEROUS, FORMATION, ROCKS, WHITA FORMATION, MONUMENTS, QUALITY, AGE, BIOGRAPHY, ENGINEERS, CIVIL ENGINEERING WHITA HILL, LANGHOLM, SCOTTISH, BORDERS, SCOTLAND UK... Show All