Search Results (18)

The House Sparrow (Passer domesticus) is a common but declining bird species in its native urban areas, partly due to reduced nesting site availability caused by modern urbanisation and loss of old architectural styles. In this study, we analysed, through a multivariate approach, the environmental factors influencing House Sparrow nest site selection in three diverse inland urban areas within the Valencian Community, Spain. We located 584 House Sparrow nests during spring 2017 and also selected 300 random points (habitat availability) in the study localities. We used Factorial Analyses of Mixed Data to assess urban feature gradients of nests and urban variables. We carried out Generalized Linear Mixed Models to compare nest locations to random points and explore variations in nesting typologies between urban zones. Specific nest site preferences vary between urban sectors, indicating that House Sparrow nests are not randomly located in urban areas. Nests are typically found near parks, schools, vacant plots, city limits, and surrounding crops, where greater vegetation cover provides abundant food sources. Low-rise terraced houses with traditional roofs and open clay tiles are consistently preferred for nesting, whereas modern architectural trends reduce nesting opportunities. Preserving green areas and old architecture with open clay tiles is essential for maintaining nesting sites and promoting House Sparrow conservation in Mediterranean urban areas. Adherence to these conservation measures may also benefit other hole-nesting species and urban wildlife reliant on green spaces. Full article

Rainfall runoff may be captured and stored for later use, but the quality of this water can be detrimental in some uses without the use of appropriately designed first-flush diverters. The rainfall runoff water quality was measured on nineteen new small-scale and two aged commercial roofs located near high traffic highways. Roof coverings included asphalt shingles, sheet metal, clay tiles, and tar and gravel. Runoff samples were evaluated for polycyclic aromatic hydrocarbons (PAHs), phosphorus flame retardants (PFRs), and pyrethroid insecticides. Eighteen small-scale roofs were subjected to a range of simulated rainfall events, while natural runoff was sampled on the commercial roofs and one small-scale roof. Runoff was analyzed for pH, conductivity, turbidity, total suspended solids, boron, iron, copper, zinc, manganese, sodium adsorption ratio, nitrate-nitrogen, seventeen PAHs, tris(2-chloroethyl) phosphate, tris(1,3-dichloro-2-propyl)phosphate, bifenthrin, cypermethrin, and lambda-cyhalothrin. Samples from four natural storm events were also analyzed for total coliforms and Escherichia coli. In addition, soils below seventeen existing gutter downspouts were sampled to determine long-term pollutant accumulation. Atmospheric deposition was the main contributor of pollutants in the roof runoff. A majority of samples fell within the U.S. EPA guidelines for non-potable urban and agricultural water reuse. Trace levels of PAHs, PFRs, and insecticides were detected, but all detections were three orders of magnitude below the USGS health-based screening level benchmark concentrations. Results indicate that diverting the first flush, based on turbidity, total suspended solids, or conductivity, can improve the overall water quality and reduce the concentrations of PAHs in harvested rainwater. Downspout soil sampling showed potential for the long-term accumulation of PAHs at concentrations exceeding the minimum human-health risk-based screening levels at these high runoff-loading locations. Full article

The 18th century roof tiles from the “Casa delle vigne”, located in the Aosta region (north-east Italy), were investigated as an example of a peculiar historical roof covering: ceramic tiles with a lead-based glaze finishing to waterproof them are used to create colourful patterns. A conservation project proposed the integration of the original tiles with new ones, produced according to traditional methods. Ancient and new tiles were analysed with Fiber Optics Reflectance Spectroscopy, micro-Raman, Fourier Transform Infrared Spectroscopy and X-ray Fluorescence Spectrometry, Thermogravimetry and Differential Scanning Calorimetry for understanding the composition and the production technology of this manufacture. Their resistance to freezing and thawing cycles was then tested, considering their exposure in the severe alpine climate of Aosta. The use of pure clays with low calcium contents, high firing temperature and lead-rich glazes was found in ancient tiles, able to outstand several freezing-thawing cycles without damages. Iron and copper pigments were used in old yellow and green glazes. Zinc-based pigment, low lead and calcium-rich glazes are used in the new ones, which remained mainly coherent to the ceramic body during the freeze-thaw test. Full article

Untreated and pH-reduced red mud is used as a potential raw material in ceramic technology. During the alkalinity reduction process, CO₂ is bubbled through the untreated red mud, which is particularly important as it can reduce the CO₂ content of the atmosphere, and the pH of the red mud. Therefore, this method serves as a CO₂ capture technique that utilizes waste as a raw material with low costs. Besides, reducing CO₂ emission, it allows the production of material suitable for brick manufacturing from waste. In this study, treated and reduced alkalinity red mud was mixed with clay in the range of 5–30 wt%, and the physical, chemical, mechanical, and technologically important properties of the dried and sintered bricks were examined. The application of reduced alkalinity red mud as an additive offers advantages, as the resulting bricks require less water for processing, are less sensitive to drying, and their strength values exceed those of the commercially available bricks. Therefore, the technique presented in the study enables the production of bricks and roof tiles with advantageous properties using waste materials. Full article

Stoneware is a ceramic material with low porosity and high mechanical properties, such as the modulus of rupture. It is essentially made of clay, feldspar and quartz and is sintered to create a mixture of glass and crystalline phases. With the projected growth rate of the global ceramics market size and the country’s development plan for 2023–2028, it is imperative that alternative raw materials for the manufacture of ceramic products be sourced so that the importation of these materials, such as feldspar, be minimized, if not eliminated. Cinder in the Philippines is mainly used as a filling material in pavements and residential areas. In this study, this resource is utilized as partial and full replacement of feldspar in a typical ternary diagram for stoneware production. Bars were formed from different formulations by the slip casting method and were sintered at 1200 °C. Physical and mechanical properties of the bars, such as shrinkage, loss on ignition, water absorption, apparent porosity and modulus of rupture were determined. Thermo-physical analyses were also carried out on the raw materials and on formulated powders. Meeting the requirements of the various quality standards for ceramics, the partial replacement of feldspar with black cinder (LF, LFBQ and LFBH) is feasible for wall and roof applications while full replacement of feldspar with black cinder (LB) is suitable for wider use as wall, floor, vitrified, industrial and roof tiles. Full article

This article presents the results of a comparative analysis performed with respect to the wear of tools used for the extrusion of a clay strand (for ceramic roof tile) made from two materials: steel NC11LV and steel Hardox 600. The aim of the studies was to determine the causes and mechanisms of wear as well as to evaluate the possibility of choosing the optimal material, mostly in respect to its resistance to intensive wear as well as an increase in the operation time. The results of the conducted investigations included: an analysis of the technology, thermovision measurements of the forming process, a macroscopic analysis combined with 3D scanning of the worn tools, ball-on-disc tests of the sliding wear resistance and hardness measurements. The obtained results demonstrated that the tools made of steel NC11LV were much less worn than those made of steel Hardox 600, as the operation time for the NC11LV steel tools was almost three times longer. The results of the ball-on-disc tests showed a similar manner of wear for both materials (with the working temperature of about 50 °C). The higher durability of the tools made from steel NC11LV can be an effect of a slightly lower coefficient of friction in the initial period of operation as well as the presence of hard carbides, which means increased hardness and thus also higher wear resistance at working temperatures. Full article

In the case of historic buildings, especially those under protection, it is important to replace elements of the roof covering, while maintaining current technical standards, to meet the requirements of the conservator. The authors of the article present alternatives to commonly used solutions, based on their experience with replacing historic building roofing with ceramic tiles made according to the production and firing technology of the nineteenth century. They emphasize that the correct/specialized restoration of existing tiles in a building makes it possible to preserve and reuse them, which is in line with the principles of historic preservation. However, due to the preservation of the roof tiles, it is not always possible to revitalize them. As a solution to the problem, the use of clay roof tiles manufactured according to 19th-century firing technology, including handmade methods, is presented, which preserves the geometry of the historic roof tiles. The approach presented by the authors meets both the requirements of conservation theory and the building standards for roofing elements. Although it is much more expensive than the solutions currently commonly used that result from modern technical requirements and tile-manufacturing technology, in the case of objects of significant cultural heritage, it is a solution that meets modern technical requirements while not compromising the original appearance of the monument. Full article

Mineral building materials suffer from weathering processes such as salt efflorescence, freeze–thaw cycling, and microbial colonization. All of these processes are linked to water (liquid and vapor) in the pore space. The degree of damage following these processes is heavily influenced by pore space properties such as porosity, pore size distribution, and pore connectivity. X-ray computed micro-tomography (µCT) has proven to be a valuable tool to non-destructively investigate the pore space of stone samples in 3D. However, a trade-off between the resolution and field-of-view often impedes reliable conclusions on the material’s properties. X-ray dark-field imaging (DFI) is based on the scattering of X-rays by sub-voxel-sized features, and as such, provides information on the sample complementary to that obtained using conventional µCT. In this manuscript, we apply X-ray dark-field tomography for the first time on four mineral building materials (quartzite, fired clay brick, fired clay roof tile, and carbonated mineral building material), and investigate which information the dark-field signal entails on the sub-resolution space of the sample. Dark-field tomography at multiple length scale sensitivities was performed at the TOMCAT beamline of the Swiss Light Source (Villigen, Switzerland) using a Talbot grating interferometer. The complementary information of the dark-field modality is most clear in the fired clay brick and roof tile; quartz grains that are almost indistinguishable in the conventional µCT scan are clearly visible in the dark-field owing to their low dark-field signal (homogenous sub-voxel structure), whereas the microporous bulk mass has a high dark-field signal. Large (resolved) pores on the other hand, which are clearly visible in the absorption dataset, are almost invisible in the dark-field modality because they are overprinted with dark-field signal originating from the bulk mass. The experiments also showed how the dark-field signal from a feature depends on the length scale sensitivity, which is set by moving the sample with respect to the grating interferometer. Full article

As a consequence of the ever-increasing urban population and continuous development of industrialization and economies of the countries around the world, the construction and demolition industry has gained eye-catching popularity, although it is also considered one of the largest producers of solid wastes globally. In an effort to counteract the negative effects of the growing construction and demolition waste (CDW) issue, the current study focuses on the utilization of mixed CDW-based materials such as hollow brick (HB), red clay brick (RCB), roof tile (RT), glass (G) and concrete (C) in the production of geopolymer binders. These materials were acquired from demolished residential buildings in an urban transformation area and then subjected to an identical two-step crushing–milling procedure to reach sufficient fineness for geopolymerization. In the first stage of the study, these materials were used singly in the production of geopolymer binders to analyse the effects of material characteristics (e.g., fineness, chemical composition and crystalline nature) on the geopolymerization performance. Thereafter, these materials were used altogether in a quinary mixture to produce geopolymer binders with the purpose of better simulating the real-life conditions where CDWs are obtained altogether and are time-/energy-consuming to separate. In order to characterize the performance of different CDW-based materials, several mixture designs were made using sodium hydroxide (NaOH) as the alkali activator. After applying thermal curing to the geopolymer pastes, compressive strength tests were performed in addition to microstructural analyses. The results showed that compressive strength values of up to 55 MPa could successfully be achieved depending on the mixture proportions. While RT was found to be the most effective material in terms of the mechanical performance of CDW-based geopolymer binders, G and C exhibited poor performances due to relatively coarse particle size distribution and an inadequate chemical composition of SiO₂ and Al₂O₃, which is a necessity for effective geopolymerization. In-depth microstructural analyses identified that geopolymer pastes with higher compressive strengths had denser and more homogeneous microstructures. The main reaction products of the geopolymer binders were mostly sodium aluminosilicate hydrate (N-A-S-H) gels with zeolite-like structures, as well as some calcium aluminosilicate hydrate (C-A-S-H) gels that arose from the use of C with a high CaO content. Our results prove that CDW-based materials can successfully be used in the production of geopolymers, and can be regarded as promising alternatives to traditional systems based on Portland cement. Full article

This study investigates the feasibility of creating a clay polymer-based composite using cowpea husk (CPH) as filler for production of roof tiles. Polymeric composites were fabricated by mixing unsaturated polyester (UPT) resin with cowpea husk at different filler weights and curing. A hybrid composite was produced with the addition of 3 wt.% clay and all samples produced were subjected to flexural, hardness and dynamic mechanical analysis (DMA) tests. The effect of clay addition on the mechanical and thermo-mechanical behaviour of formulated composites was investigated. The morphological analysis of the mono and hybrid system shows a rough and coarse inhomogeneous surface with voids created due to the addition of CPH filler for the mono reinforced and clay uniformly filling the voids that were created by the CPH in the hybrid composite. It is observed that hardness, tensile modulus and flexural modulus of hybrid composites increase with an increase in the CPH contents, while the strength and flexural strength all decrease with filler content. The optimal composition was obtained using Grey relational analysis (GRA) at 18% CPH for both mono and hybrid composite. The results imply that the composite combination can be used in making rooftiles and/or also in applications where low strength is required. Full article

A novel roofing tile was developed containing various types of nanoparticles of titanium dioxide (TiO₂). Experiments were conducted using three types of TiO₂ nanoparticles with and without polyethylene glycol (PEG). All types of newly developed nanomaterials were characterized using X-ray diffractometry. Particle size distribution analysis was performed and specific surface area was determined using the Brunauer–Emmet–Teller method. SEM imaging was used for the morphological characterization of nanoparticles. Commercial ceramic roofing tiles underwent a dip-coating procedure to obtain the desired photocatalytic surface. The TiO₂ anatase samples exhibited greater surface areas of nanoparticles, thus providing potentially the highest photocatalytic efficiency. Full article

In addition to the known uses of natural clays, less publication attention has been paid to clays returned to the production process. Industrially recovered natural clays such as bricks, tiles, sanitary ceramics, ceramic roofing tiles, etc., are applicable in building materials based on concrete as an artificial recycled aggregate or as a pozzolanic type II addition. In this way, the building products with higher added value are obtained from the originally landfilled waste. This paper details the research process of introducing concrete with recycled brick waste (RBW) up to the application output. The emphasis is placed on using a RBW brash as a partial replacement for natural aggregates and evaluating an RBW powder as a type II addition for use in concrete. A set of the results for an RBW is reported by the following: (a) an artificial RBW fine aggregate meets the required standardized parameters for use in industrially made concrete, (b) a RBW powder is suitable for use in concrete as industrially made type II addition TERRAMENT showing the same pozzolanic reactivity as a well-known and broadly used pozzolan-fly ash, and (c) such an RBW as aggregate and as powder are, therefore, suitable for the production of industrially made TRITECH Eco-designed ready-mixed concrete. Full article

A classification method of hyperspectral reflectance images named CHRIPS (Classification of Hyperspectral Reflectance Images with Physical and Statistical criteria) is presented. This method aims at classifying each pixel from a given set of thirteen classes: unidentified dark surface, water, plastic matter, carbonate, clay, vegetation (dark green, dense green, sparse green, stressed), house roof/tile, asphalt, vehicle/paint/metal surface and non-carbonated gravel. Each class is characterized by physical criteria (detection of specific absorptions or shape features) or statistical criteria (use of dedicated spectral indices) over spectral reflectance. CHRIPS input is a hyperspectral reflectance image covering the spectral range [400–2500 nm]. The presented method has four advantages, namely: (i) is robust in transfer, class identification is based on criteria that are not very sensitive to sensor type; (ii) does not require training, criteria are pre-defined; (iii) includes a reject class, this class reduces misclassifications; (iv) high precision and recall, F ${}_1$ score is generally above 0.9 in our test. As the number of classes is limited, CHRIPS could be used in combination with other classification algorithms able to process the reject class in order to decrease the number of unclassified pixels. Full article

The former Artistic and Industrial Recreation Pavilion, which was designed by Antonio Palacios (1874–1945) and built for the Galician Regional Exhibition held in 1909 in Santiago de Compostela (Galicia, north-western Spain), and which currently houses a nursery school, was completely restored in 2018. The main purpose of the restoration was to recover the original exterior colour of the building. For this purpose, a study was undertaken to identify the original colour of the paintwork by first consulting historical archives and then conducting a micromorphological analysis of stratigraphic paint samples by stereomicroscopic examination and scanning electron microscopy (SEM) coupled with electron dispersive spectroscopy (EDS). Three reformations of the building are documented: one carried out in 1926, when the metal roof was replaced with a tile roof; another conducted between 1967 (when the old pavilion was described as a "destroyed building") and the mid-1970s (when it began to be used as a nursery); and finally, another in 1981, when the building was repainted. The analytical results revealed layers of white or yellow ochre (vanilla) paint corresponding to different periods. The presence of titanium (Ti) in the paint was used as a marker of its age, as titanium white was first formulated in 1921. The original layers include Zn in their composition, indicating that zinc oxide (ZnO) was the pigment used in the “snow” white paint probably used on the building in its first years of existence. In all cases, the pigment base is lime mixed with silicates, kaolin and other clays. Full article

The development of new, environmental friendly building materials with photocatalytic properties remain still on the top of the investigations both for academy and industry. The main drive is the increasing air pollution and the greenhouse gas emissions that have negative effect on public health and buildings. Ceramic roofing tiles functionalized with TiO₂ can contribute on tackling these severe environmental problems by improving their properties. In this study, heavy clay ceramics manufactured from clay-body mixture and a Bayer process bauxite residue (ferroalumina) are used as substrates for the deposition of TiO₂ coatings in order to produce self-cleaning ceramic surfaces. The process is based on the thermal hydrolysis of TiCl₄ which takes place in a CVD reactor under atmospheric conditions. All coated samples were annealed at 600 °C and characterized in means of XRD, SEM/EDS and degradation ability of an organic pollutant. The formation of titania mixed phases (rutile and perovskite) shows positive results regarding the photocatalytic activity of the samples. The ones containing ferroalumina decomposed 100% the indigo carmine solution after 4 h, in comparison with the reference one which presented lower efficiency. Finally, this paper addresses technical feasible solutions for the production of photocatalytic active ceramics within the concept of circular economy and environmental sustainability. Full article