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The present study describes research carried out to evaluate the mineralogical, geochemical and technological properties of indurated shale-quarry wastes and assess the suitability of these low-cost and locally available quarry wastes generated from crushed indurated shales for possible use as alternatives to fresh raw materials in the manufacture of roofing-tile products. Firstly, the mineralogical and chemical properties of the indurated shales were investigated by X-ray diffraction (XRD) and X-ray fluorescence, while their physical properties were identified by grain-size distribution, Atterberg limits, and clay activity. Samples of indurated shale-quarry wastes (ISQWs) were subjected to heat treatment at elevated firing temperatures to provide the required strength and durability and their ceramics properties (linear shrinkage, weight loss, water absorption, bulk density, and flexural strength) were determined. From the results, the ISQWs were composed predominantly of fine particles with medium plasticity and clay activity with values generally >0.75. The mineralogy revealed a predominance of aluminosilicates (illite-kaolinite-smectite-chlorite) with large quartz contents and variable percentages of carbonate and feldspar. The oxides were dominated by SiO2 and Al2O3, small amounts of ferromagnesian minerals, and considerable amounts of alkalis (K2O and Na2O) which act as fluxes. The CaO concentrations were variable and related to carbonate contents. Characterizations based on compositional ternary (total clay mineral-carbonate-quartz + feldspar) systems, Casagrande clay workability charts, and Winkler and McNally diagrams revealed their suitability for ceramics applications as the majority of ISQW samples fell within the specifications for roofing tiles. The ISQWs fired at a high temperature of 1000°C revealed considerable weight loss, reduction in both linear shrinkage and water absorption with insignificant increase in flexural strength. In order to achieve excellent ceramics properties and further reduce sintering temperature for their suitability as raw materials in the production of roofing tiles, beneficiations of ISQWs are highly recommended. [ABSTRACT FROM AUTHOR]

In order to rate the drying behavior of different clay raw materials it is necessary to establish the criteria for comparison. Mineralogical composition, clay minerals content, particle size distribution, packing, porosity, forming procedure, and raw material aging are known as intrinsic parameters. Due to the fact that these parameters are cross linked and are usually inter-dependently related to each other, the attempts to set up a criteria for correlation between intrinsic parameters and drying sensitivity has been limited. That was the reason why the estimation of the cracking tendency was linked with the easiness of the drying process in each reported method. The most applied methods for estimation of the drying sensitivity of clays in the ceramic industry were proposed by Bigot, Ratzenberger, Piltz, Hermansson and Varlamov. The fact that previously mentioned methods were not compared up till know has defined the main objective of this study. The only reported comparison was between Bigot and Ratzenberg drying sensitivity index. The second objective of this review was to present these methods and to estimate the drying behavior of tree different clay raw material. It was confirmed that Varlamov method is very simple, accurate and fast. It is correlated with the mineralogical composition of clay and cannot be used for description of the drying kinetic. The other two models can provide info about the drying kinetic. Piltz model is the most relevant for describing the drying behavior at the beginning of the drying. The results have confirmed that the most suitable conclusion about the drying behavior of the tested clays is obtained when results from Bigot, Piltz and Varlamov methods are available. [ABSTRACT FROM AUTHOR]

Making full use of industrial by-products is an effort to achieve 'zero waste' and promote greener development. Methyl ester residue (MER) is a waste commonly found in oleochemical manufacturers, such as palm oil mills. Contrary to conventional cement and clay, MER was employed as an alternative binder to fabricate a novel eco-friendly roofing tile, henceforth referred to as MER-RT. Parameters tested were transverse strength, water absorption, sulfate resistance, and fire resistance. During the optimization phase, a range of 6–11% of MER was mixed with a fixed composition of fly ash and fine sand, compacted and cured at 190° C for 12–48 hours. Considering the electrical energy consumption, the optimal curing duration chosen was 24 hours as this MER-RT achieved a dry transverse strength of 4112 N whereas curing for an additional 18 hours further contributed to only 16% strength gain. The optimal MER-RT was found to contain 10% MER as it showed the highest dry transverse strength (6410 N), the highest wet transverse strength (3681 N) and the lowest water absorption percentage (2.67%), meeting the American Society for Testing and Materials (ASTM) standards. Besides exhibiting minimal corrosion under the sodium sulfate test, the optimal MER-RT was non-flammable and did not undergo structural changes when exposed to fire. The study reveals the potential of both MER and fly ash as green binders and fillers for roof tiles, despite their origins as industrial waste. • Up to 10% of methyl ester residue could be used as a green binder in roofing tiles. • The roofing tiles produced reached a dry transverse strength of up to 6410 N. • The optimized specimen has good durability against water, sodium sulfate and fire. [ABSTRACT FROM AUTHOR]

Re‐use and recycling of bricks – Status quo and perspectives Brick recycling can not only substitute raw materials for the production of new bricks, but also save primary aggregates in particular and thus conserve resources in many other product areas. New developments in the separation and sorting technology of modern recycling plants allow the prognosis that in the future the building material brick can be almost completely returned to the material cycle. Which route the used bricks actually take will depend on the prevailing technical, environmental and, not least, economic conditions at that time. From an economic point of view, the most important factors will be the further development of selective demolition processes, suitable processing and sorting methods, and marketing potential. Research and development in the brick industry will of course continue to be oriented towards the requirements of modern brick construction methods. However, it is becoming increasingly important in terms of the manufacturer's product responsibility that an environmentally sound, resource‐conserving and at the same time economic recycling of the so‐called "end‐of‐life" product will also be possible after the first phase of use. [ABSTRACT FROM AUTHOR]

Waste can be considered a crisis across the world, especially in the Global South where landfills are collapsing and vector-borne illnesses are increasing. Due to the increase in the amount of waste plastic in the environment, different uses of recycled plastics are being investigated. One such use is roofing tiles. This has been put in place in Sri Lanka through the Waste for Life organization. Here, recycled polyethylene is filled with rice husk particles. Due to the hydrophilic nature of the rice husk, the strength of the polyethylene composites decreased with increasing rice husk filler. Since the roofing tiles do not need to support a large load, the loss in strength should not be too detrimental. However, the creep behavior was improved with 10% and 20% filler. This is important in that the temperature on the roof can reach high temperatures. Front view of composite sample: (a) 0% filler showing necking, (b) 5% filler, (c) 10% filler and (d) 20% filler showing both breakage of filler material and decohesion of filler material from PE matrix. [ABSTRACT FROM AUTHOR]

Clay roofing tiles have been subjected to freezing-thawing cycles. Analyses performed on the ceramic material highlight changes in the pore size distribution, and the consequent modification of the capillary suction behaviour. A model using intermingled fractal units (IFU) to mimic the porous structure satisfactorily describes the observed porosity evolution. Additionally, it successfully predicts the sorptivity coefficient. The results obtained are in good agreement with the experimental ones. In order to verify the ability of the IFU model to predict sorptivity coefficient, a comparison has been shown with other two analytical procedures. It is possible to note that IFU model better fits experimental values than other models found in the literature. [ABSTRACT FROM AUTHOR]

This study explores the possibility of substituting clayey raw materials using ceramic sludge in clay roof tile production. The tile specimens were manufactured in an industrial scale plant by replacing clay with ceramic sludge: 0%, 10%, 15%, 20% and 25% (by weight). Strength properties (transverse breaking strength, modulus of rupture, bulk density), durability properties (water absorption, water penetration, salt crystallization, efflorescence, acidic and alkaline resistances) and run-off qualities (Ph, total solids, BOD, heavy metal concentration) were examined. Thermal properties of the sludge incorporated tiles were investigated and compared with the conventional tiles. Bulk density reduces with increasing the sludge content, which is a favorable property of roof tiles. Transverse breaking strength was optimum at 20% sludge, indicating 22.9% increment compared to the conventional tile. Clay replacement up to 20% is acceptable, satisfying water absorption and penetration in standards. No efflorescence and Sulphuric acid attack were disturbed for any specimen. At 12:00 noon, the tile with 20% sludge reduced indoor temperature by 2.8 °C, providing more comfortable shelter compared to the conventional roof tiles. For the 25% sludge incorporated tiles, run-off showed 120.2 mg/l total solid concentration, 7.36 Ph value and 5 mg/l BOD5 value, 0.01 mg/l, 0.05 mg/l, 0.06 mg/l, 0.04 mg/l Cd, Cu, Pb and Zn concentrations, respectively; while for the other tiles, run-off had lesser concentrations, which are favorable for rain water harvesting process. With 20% sludge, tiles achieved better structural, durability and thermal properties compared with the conventional tiles while satisfying the standard limits of run-off qualities. [ABSTRACT FROM AUTHOR]

Ceramic roofing tiles were first invented during the Early Bronze Age (or Early Helladic [EH] period, ca. 3100-2000 BCE) and have been identified at 22 sites in mainland Greece. In this paper, I present a newly discovered assemblage of EH tiles from the site of Mitrou (East Lokris) and offer the first detailed, comparative analysis of EH tile production. I demonstrate that there was a shared tradition for the appropriate form and dimensions of tiles in mainland Greece. This uniformity, however, belies heterogeneity in production among sites and through time. The reconstructed chaîne opératoire of Mitrou's tiles, for instance, has affinities with the tiles of Zygouries (Corinthia) and Kolonna (Aegina), but not of the later House of the Tiles at Lerna and most tiles from Tiryns in the Argolid. With these results, I reveal a distinct network of interaction in mainland Greece in which construction knowledge was disseminated and maintained. [ABSTRACT FROM AUTHOR]

Global warming is one of the global major issues owing to excessive emission of greenhouse gases (GHGs). Construction industry accounts for about 40% of the total emissions and conventional building materials are believed to be the major contributors. This paper attributes to the potential of manufacturing environmental friendly building material namely EnO-Roofing tiles by utilizing only catalyzed waste engine oil (WEO) as a binder together with coal-fired ash (CFA). It was discovered that waste engine oil under specific temperature and condition would induce its chemical transformation from liquid to solid state via complex oxy-polymerization reaction. The functional groups of waste oil which initiated the chemical reactions and led to the stiffening of tiles were analyzed by using Fourier Transform Infrared Spectroscopy (FTIR). In addition, a series of manufacturing processes were carried out to determine the optimized condition for the production of catalyzed EnO-Roofing tiles. Standard specification tests for EnO-roofing tiles were conducted in terms of flexural strength, water absorption and permeability as per requirement of American Society for Testing and Materials (ASTM C 67–07a, C 1167–03, and C 1492–03). Moreover, the embodied carbon (EC) and embodied energy (EE) of the novel tiles were found at 0.4178 kgCO 2 /kg and 1.27 MJ/kg respectively, which is relatively lower with respect to the conventional roofing tiles. Conclusively, conversion of existing resources, recycled and reused waste materials, manufacture of environmental friendly roofing tiles are the prominent outcome of this paper. [ABSTRACT FROM AUTHOR]

Biodeterioration damage is an important issue in conservation and restoration of built heritage, especially when ceramic materials are used. Biological colonization of ceramic roofing tiles by lichens is a common phenomenon. However, there are no reports to date of lichens removal from unglazed roofing tiles for conservation purposes. This paper for the first time reveals the results of a combined procedure undertaken to assess the removal of lichens on different kinds of unglazed ceramic roofing tiles by treatments based on both dual sequential laser irradiation and treatment using Acticide ® CF biocide. Three species of lichens were identified: Verrucaria nigrescens , Calogaya decipiens and Pyrenodesmia teicholyta . The chemical and mineralogical composition of roofing tiles were characterized by X-ray fluorescence (XRF) spectrometry, optical polarized petrographic microscopy, and X-ray diffraction (XRD). Laser irradiation was accomplished by applying sequences of nanosecond laser pulses at two wavelengths (1064 and 266 nm). After dual sequential laser irradiation a biocide was applied. To assess the combined effect of both treatments several techniques were used, including stereo and fluorescence (FM) microscopies, scanning (SEM) and transmission (TEM) electron microscopies, and FT-Raman spectroscopy. Chemical composition of the analyzed roofing tiles was shown as a relevant factor regarding the degree of interaction between the biological colonization and the substrate, and hence, the bioweathering effect. The combined procedure has proved to be very effective in ablating cortical layers in all species, or even complete areolae in V. nigrescens , enhancing biocide effect in the thalli of C. decipiens and P. teicholyta , and producing the complete damage of both bionts. [ABSTRACT FROM AUTHOR]

Increased demand for affordable housing and the limited availability of flat terrain for its construction are two major problems facing the provision of houses of acceptable quality in many countries around the world. There is limited research integrating the utilization of a stepped approach to sloping terrain with appropriate housing models to minimize slope instability potential. This paper introduces a new semitiered housing model where the footprint of the house is located on tiers prepared with short vertical cuts of 1.5-2m. Such vertical cuts are found to be stable with laterite soil which is a commonly available type of soil in the tropics. The excess soil generated from cut material was transformed into cement stabilized rammed earth, which is a cost effective material with low embodied energy. This is an ideal candidate for the construction of retaining walls and foundations, and such applications are demonstrated with adequate details. Further, many other types of sustainable building materials are highlighted with a case study of this housing model in a scheme of 13 housing units in Sri Lanka. The attention to detail required in construction and the applicability of alternative building materials and methods to improve the sustainability of such houses have been discussed in detail. These semi-tiered houses have the potential to address many of the current construction challenges. [ABSTRACT FROM AUTHOR]

In this paper, blended fly-ash cenospheres/clay composites are explored as potential material for roofing tiles. In view of impact on roofs during hailstorms, the goal is to improve the impact resistance of roofing tile materials. It is hypothesized that the impact damage resistance of tiles can be improved while reducing their densities by incorporating hollow fly-ash cenospheres with base clay. Towards that, four types of composites, namely clay, clay + filler, clay + fly-ash and clay + filler + fly-ash are fabricated and evaluated under dynamic impact loading with 1 J impact energy. Changes in microstructure, densities and degree of damage in the four types of composites are compared. The addition of fly-ash cenospheres appears to improve the structural integrity of the tiles by reducing gaps observed in clay tiles. The highest reduction in density is observed in clay + fly-ash composites of approximately 36% as compared to clay samples. Whereas, a reduction in the degree of damage of about 22% and 26% are observed in clay + fly-ash and clay + filler + fly-ash specimens, respectively. Even though clay + filler and clay + filler + fly-ash manifested higher peak forces and lower degree of damage than clay + fly-ash composite, the reduction of densities are only 3.48% for clay + filler and 29.85% for clay + filler + fly-ash. Therefore, a combined consideration of degree of damage and density of composites reveals that clay + fly-ash composites are superior as compared to clay and other composites investigated in this study. [ABSTRACT FROM AUTHOR]

Biocolonization of building materials is a critical problem for the durability of constructions. Industrial experience shows that straw coloured roofing tiles are more prone to colonization than red roofing tiles, even having similar characteristics. The aim of this work is to explain the difference of biocolonization between different colour roofing tiles. The chemical composition of the surface of straw coloured and red roofing tiles, the phase composition and the microstructure of the roofing tiles were determined by WD-XRF, XRD and SEM-EDX, respectively. The pore size distribution was carried out by Hg porosimetry. The solubility was studied by determining the soluble salts (Ca, Mg, Na, K, Cl and SO4 2-) by ICP-OES and ionic chromatography. Roofing tile bioreceptivity was evaluated by determining fluorescence intensity using a pulseamplitude- modulated (PAM) fluorometer, and cyanobacteria Oscillatoria sp. The results obtained show higher concentration of calcium and sulphur in straw coloured roofing tiles surface, and higher solubility than red roofing tiles. Moreover, according to the results obtained in bioreceptivity assays, straw coloured roofing tiles are more prone to colonization than red roofing tiles, so, there is a relationship between surface properties of roofing tiles and biocolonization, as it is observed in industrial products.La colonización biológica es un fenómeno que afecta de forma negativa a la durabilidad de los materiales de construcción. A nivel industrial se ha observado que las tejas de color paja muestran mayor tendencia a la colonización biológica que las tejas de coloración rojiza, incluso cuando ambas presentan características similares. El objetivo de este trabajo es determinar la causa de las diferencias de biocolonización entre tejas de diferente color. Para ello, se ha determinado la composición química de la superficie de tejas de color paja y de color rojo mediante WD-FRX, la composición mineralógica por DRX, la microestructura de la superficie mediante MEB-EDX, la distribución del tamaño de poros mediante porosimetría de mercurio, y la solubilidad (Ca, Mg, Na, K, Cl and SO42- por ICP-OES y cromatografía iónica). Se ha evaluado la biorreceptividad midiendo la intensidad de fluorescencia con un fluorómetro, utilizando la cianobacteria Oscillatoria sp. Los resultados muestran una mayor concentración de calcio y azufre, y una mayor solubilidad de éstos, en la superficie de las tejas paja, y éstas presentan una mayor tendencia a la colonización. Por lo tanto, el hecho de que presenten sales solubles en superficie favorece la biocolonización, y con ello, el deterioro estético y funcional del tejado.

Rice Husk Ash (RHA), a waste from firing process of clay products, has no proper usage. For this study, roof tile specimens were manufactured by replacing clay with different RHA percentages (i.e., 0%, 5%, 10%, 15% and 20%) in an industrial scale plant, so as to determine the effect of waste RHA from a brick firing process on structural, thermal properties and run-off qualities of clay roof tiles. For 10% replacement of clay with RHA, transverse breaking load was increased by 45.97% indicating higher ductility compared with that of the conventional tiles. Bulk density is reduced with the percentage of RHA added, promising a light-weight roof tile, a favourable tile for a roofing material. With increasing RHA content, water absorption increases. RHA replacement up to 15% is desirable, satisfying the water absorption limit according to standards. RHA replacement up to 20% doesn’t affect on the water penetration property. RHA mixed roof tiles can reduce the indoor temperature, feeling more comfortable for inhabitants. Collected runoff coming along the 10% RHA mixed clay roof tiles has a pH value of 7.22 and total solid concentration of 118.67 mg/L, indicating RHA mixed roof clay tile will not cause any severe impact on the runoff. Hence this harvested runoff can still be utilized for non-potable activities while enhancing the strength and thermal properties of clay roof tiles. [ABSTRACT FROM AUTHOR]

Climate change has become a major issue in recent years owing to the emission of greenhouse gases. Mitigation measures are required to overcome the challenges pertained to greenhouse gases emissions. This research paper attributes to the utilization of catalyzed waste vegetable oil as a binder for the production of roofing tiles to replace the conventional construction materials such as clay and cement. A novel methodology of utilizing catalyzed waste oil incorporated with sand and filler was adopted and the innovative product produced is entitled as catalyzed Vege-Roofing tiles that discovered to be economical and environmentally friendly in contrast to the traditional binders. It is believed that an extended heat curing of vegetable oil resulted in a complex oxy-polymerization reaction converting it into a rigid binder. Triplicate prototypes samples were manufactured to optimize the final conditions for the fabrication of catalyzed Vege-Roofing tiles. Optimized conditions were then implemented to produce standard catalyzed Vege-Roofing tiles and these fabricated tiles have shown flexural stress of up to 12 MPa for 18 h of curing. Moreover, these novel tiles were tested for permeability and water absorption according to the ASTM standards and have shown impermeability and remarkably low water absorption. Progressively, the embodied energy and embodied carbon requirements for these tiles found to be 0.64 MJ/kg and 0.327 kg CO 2 per equivalent respectively which is quite less in comparison to the traditional binders. Conclusively, environmentally friendly and economic production of tiles, conservation of existing resources and overcoming the issue of waste management are the remarkable outcomes of this research. [ABSTRACT FROM AUTHOR]

Este trabalho tem por objetivo avaliar o efeito da variação, na composição de massa cerâmica, dos dois principais tipos de argilas de Campos dos Goytacazes, norte do Estado do Rio de Janeiro, no processamento e na performance técnica da cerâmica vermelha. As argilas, denominadas de "forte" e "fraca", foram inicialmente submetidas a ensaios de caracterização mineralógica, química e física. Em seguida, foram preparadas composições variando a quantidade das argilas. A plasticidade foi avaliada pelo método de Atterberg. Foram preparados corpos de prova por prensagem uniaxial a 20 MPa para queima a 900 ºC. As propriedades tecnológicas avaliadas foram: retração linear, absorção de água e tensão de ruptura à flexão. Os resultados indicaram que as argilas são mineralogicamente semelhantes com a presença de caulinita, quartzo, gibsita e mica muscovita. A argila "fraca" reduz significativamente a absorção de água e retração linear de queima da cerâmica. Entretanto, ocorre também uma redução da resistência mecânica. Este comportamento é atribuído à maior presença de quartzo.This work has for objective to evaluate the effect of the variation, in the ceramic body composition, of the two main types of clays from Campos dos Goytacazes north of the State of Rio de Janeiro, in the processing and technical performance of the red ceramic. The clays designated as "strong" and "weak" were previously submitted to mineralogical, chemical and physical characterization tests. In the sequence, compositions were prepared varying the amount of the clays. The plasticity of the clays was determined by the Atterberg method. Specimens were prepared by uniaxial pressing at 20 MPa before firing at 900 ºC. The technological properties evaluates were: linear shrinkage, water absorption and flexural strength. The results showed that the clays are mineralogically similar with the presence of kaolinite, quartz, gibbsite and muscovite mica. The "weak" clay significantly decreases the water absorption and the firing linear shrinkage of the compositions. However, it was also observed a decrease in the mechanical strength. This behavior is due to the presence of quartz in a higher amount.

Este trabalho teve por objetivo reformular uma típica massa de telhas produzida no município de Campos dos Goytacazes, RJ, variando a quantidade de areia. As matérias-primas, massa argilosa e areia, foram inicialmente submetidas a ensaios de caracterização mineralógica, química e física. Foram preparados corpos de prova por extrusão para queima nas temperaturas de 850, 950 e 1050 ºC. As propriedades avaliadas foram plasticidade, absorção de água, retração linear de queima e tensão de ruptura à flexão. Os resultados indicaram que as propriedades avaliadas melhoraram com a utilização de areia.This work has as objective to reformulate a typical roofing tile body produced at Campos dos Goytacazes, RJ, Brazil, varying the amount of sand. The raw materials, clayey body and sand, were initially submitted to mineralogical, chemical and physical characterization tests. Specimens were prepared by extrusion to fire at 850, 950 and 1050 ºC. The evaluated properties were: plasticity, water absorption, firing linear shrinkage and flexural rupture strength. The results indicated that the evaluated properties improved with the use of sand.

Current design loads for roofing tile systems in the U.S. are determined based on a standardized wind tunnel testing method developed in the 1990s to examine wind-induced pressures on the upper and lower surfaces of the tile. The method neglects several key parameters that are well known to affect wind loading (e.g. wind angle, specimen shape, etc.). The research objective of this study is to investigate this method by [1] characterizing wind-induced surface pressure distributions on field tiles for varying wind angles of attack and [2] measuring load path intensity through mechanically fastened tile attachments. Surface pressure distributions were measured on three full-size, rapid prototyped roofing tile models with 256 pressure taps immersed in wind flows. The models are geometrically identical to low-, medium- and high-profile concrete roofing tiles that are widely used in high wind areas. Additionally, their real counterparts were instrumented with load cells to measure reaction forces at mechanical fasteners. The results highlight areas of the method that are lacking in specificity and shows that low-resolution pressure measurement may yield conservative parameters for low- and medium-profile tiles but is potentially not conservative for asymmetric (s-shaped) high-profile tiles. [ABSTRACT FROM AUTHOR]

This article aims to study the mass transient diffusion in solids with an arbitrary shape, highlighting boundary condition of the third kind. To this end, the numerical formalism to discretize the transient 3D diffusion equation written in generalized coordinates is presented. For the discretization, it was used the finite volume method with a fully implicit formulation. An application to drying of roof tiles has been done. Three models were used to describe the drying process: (1) the volume V and the effective mass diffusivity D are considered constant for the boundary condition of the first kind; (2) V and D are considered constant for the boundary condition of the third kind and (3) V and D are considered variable for the boundary condition of the third kind. For all models, the convective mass transfer coefficient h was considered constant. The analyses of the results obtained make it possible to affirm that the model 3 describes the drying process better than the other models. [ABSTRACT FROM AUTHOR]

In a very dynamic and volatile business environment, multinational companies view the intra-company exchange as a factor of developing the enterprise's capacities and total revenue growth. The paper is aimed at performing econometric evidence of the total revenues of "Tondach" company, based on the collected economic indicators of "Tondach" company development in nine countries. For each individual country, variables on total revenue, total company's investment in the country, the number of employees and the value of intra-company exchange were used. Besides these variables, the model will use two additional ones: population and rating for each individual country. It was established that the intra-company exchange has a positive and significant effect on the total revenue of companies in the Tondach Group in the observed countries and the observed period of time. With respect to rating, as the second independent variable of special interest, we observe a positive and strong effect on total revenue. This result also proves our claim that countries in the region, with a higher risk factor, which are not members of the integration, have a lower rating, which in turn has a direct impact on lower revenues. [ABSTRACT FROM AUTHOR]

Roofs surfaces are frequently used to catch water for drinking in many countries, so the presence and mobilisation of material into runoff water can be an important process to consider. This paper investigates the origin and mobilisation of trace elements from roofing tiles. Our work suggests that trace elements can mobilise into roof runoff. However, lead by contrast, appears to have accumulated at the surface of tiles exposed to busy automobile traffic that used leaded fuel (confirmed by X-ray fluorescence). Although lead is relatively immobile on the tile surface, the potential for leaching by acidic rain (pH < 4) means that the guidelines for lead in drinking water may be exceeded during some rainfall events. [ABSTRACT FROM AUTHOR]

The suitability of Triassic Red Beds from northern Jaén in the production of structural clay products has been evaluated. These materials have high phyllosilicate contents (36-69%), although some samples are enriched in quartz (

This work presents the first review on biodiversity, biodeterioration and bioreceptivity of architectural ceramics. Literature dating from 1972 to 2014 was compiled and analysed in order to summarise the current knowledge and to facilitate a better understanding of the subject. Data regarding biodiversity found on architectural ceramic materials was described for three typologies: bricks, roofing tiles and glazed wall tiles. A vast biodiversity has been identified on these ceramic materials, from bacteria to more complex organisms, such as plants. Bricks were the most studied substrate, while literature on glazed wall tiles was scarce. The highest biodiversity was found on bricks, may be due to the fact that this was the most studied typology. Several works regarding the colonization of ceramic roofing tiles by lichens were found in the literature, which led us to realise that this is a topic that arouses the attention of several researchers. Photoautotrophic microorganisms found on glaze wall tiles represented a considerable biodiversity in this ceramic typology, with many genera in common with those identified on bricks and roofing tiles. Nevertheless, in the searched literature, different methods had been used to identify and characterize the organisms. This made the comparison of the global biodiversity found on these substrates difficult. Architectural ceramic materials exposed to outdoor conditions are often affected by biodeterioration. This worldwide problem can cause aesthetical, physical and chemical damages on ceramic materials. The distinct biodeterioration processes occurring on the different substrates found on architectural ceramic materials are explained in detail. The relationship between the ceramic intrinsic properties and bioreceptivity was discussed. Porosity and surface roughness seemed to play a major role in bioreceptivity to colonization. Ceramic microstructure has a strong influence on the resistance to biodeterioration. Finally, the authors come to the conclusion that there are many gaps in the knowledge, especially concerning glazed ceramics, and thus, further research was proposed. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this study was to examine the effect of the hydroxyl radicals (free and bound) produced by a TiO2 mesoporous coating immobilized on the surface of clay roofing tiles. The efficiency of the coating was determined by microbiological and photochemical tests. In the microbiological test (pour plate method), use was made of the test bacteria Pseudomonas aeruginosa, while the photochemical test involved the degradation of para-chlorobenzoic acid, monitored by HPLC method. Both experiments were carried out without and with a scavenger (methanol and tert-butanol). The results of the measurement of the photocatalytic efficiency, and the observed changes in the measured contact angle (sessile drop method), imply the existence of a photo-induced hydrophilicity of the TiO2 coated porous substrates. The newly designed coating represents a medium which efficiently hinders bacterial adhesion. The experiments demonstrated the existence of self-cleaning and slight self-disinfecting properties of the mesoporous coating. [Copyright &y& Elsevier]

Abstract: Stand-off photovoltaic systems are a popular measure for retrofitting of existing pitched roofs. Panels are generally mounted parallel to the existing roof coverings, usually roofing tiles. Full scale and wind tunnel experiments have been performed to determine the net uplift loads on these systems, which can be applied to calculate the loadbearing system. In the wind tunnel, the effect of distance between panel and roof has been investigated. Results show that loads can be expected that are substantially lower than the external loads on the roof surface, as given in wind loading standards. The effect of distance between PV system and roof surface is relatively small. The loads on the underlying roof are not significantly higher or lower compared to the case without system. [Copyright &y& Elsevier]

Abstract: Roofing solutions with high capacity to reflect incident solar radiation, the so-called cool roofs, can provide an effective answer to summer overheating of either individual buildings or whole urban areas. Nowadays, commercial cool roof products are mainly represented by organic membranes and coatings, but ceramic tiles can offer an interesting alternative or complement in view of their high durability. This work presents the procedure through which a traditional white engobe and a glazed tile with high solar reflectance are developed by the introduction of suitable raw materials and pigments, in the perspective of production by commonly used industrial processes. The solar performance was checked for both light and dark supports and for different engobe thicknesses up to 250μm; the estimated solar reflectance values were correlated with surface properties such as microstructure, mineralogical composition, and roughness. The best performing engobe, applied as a 200μm layer, improved solar reflectance of the sample up to 0.90. Three different glazes were then applied on engobed samples and were found to slightly affect the reflectance and improve the resistance to mechanical stress or weathering. A white gloss glaze was found to be the best performing one in terms of solar reflectance. [Copyright &y& Elsevier]

AN ASSEMBLAGE OF more than 2500 fragments of tile was recovered from within the precinct of Melrose Abbey during excavations in 2009. The collection includes a large group of decorated floor tiles, the designs of which have links with the 'Westminster School', and which are unlike any other previously excavated at the abbey. This paper places the group in context and considers the implications of the find. [ABSTRACT FROM AUTHOR]

Clay roofing tiles fired at five different temperatures (900, 920, 960, 1,000, and 1,020°C) were subjected to the investigations of textural characteristics and frost resistance prediction. The closed container and hydraulic pressure mechanisms proved to be dominant at lower firing temperatures (900 and 920°C), whereas micro-ice-lens formation mechanism have significant role at higher temperatures (960 and 1,000°C). The highest resistance is noticed for the samples fired at 1,020°C where the frost action mechanisms are balanced because the porous structure that compensates the local stresses developed during freezing. The prediction of frost action durability of clay roofing tiles, the appearance of the first cracks, and the prediction of frost action mechanisms given by the statistical model, showed a high level of agreement. The statistical model contains capillary pores (), and the ratio of frozen and unfrozen water () as significant parameters for describing susceptibility to closed container mechanism and micro-ice-lens formation mechanism, respectively. [ABSTRACT FROM AUTHOR]

Extracts are presented from applications filed with the European Patent Office including applications for the usage of niacin to increase muscle weight, the invention of pan tile, a type of roofing tile, and an invention for heating railroad switches.

Extracts are presented from applications filed with the European Patent Office including applications for the usage of niacin to increase muscle weight, the invention of pan tile, a type of roofing tile, and an invention for heating railroad switches.

Extracts are presented from applications filed with the European Patent Office including applications for the usage of niacin to increase muscle weight, the invention of pan tile, a type of roofing tile, and an invention for heating railroad switches.