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[en] At present, building is considered one of the most polluting activities , however, the sector is becoming aware and taking responsibility for the impact it generates throughout the life cycle of buildings . In the development of the idea of sustainability in the construction, it has been investigated in studies related to the improvement of the conditions of comfort and improvement of the quality of life of the people. In this sense, there are many studies found that intend to incorporate sepiolite for its properties in various materials for the absorption of formaldehydes . Therefore and in view of the results obtained by other authors, the design of a prefabricated panel for indoor false ceiling is proposed. The base material of this panel will be a plaster with sepiolite load in its composition to get it to help improve the indoor air quality of the homes in which it is installed. To achieve the objective, an experimental plan has been developed, divided into three phases: In the first phase, gypsum and plaster were used, following the technical prescriptions of Norma UNE-EN-13279: Yesos de construcción y conglomerantes a base de yeso para la construcción . Said norm, specifies the requirements that this type of material must comply with in terms of hardness, bending and compression, which are the parameters taken into account for this study...
[en] The different systems, and urban subsystems, are not isolated, although today they are managed as such, but integrated into a multidimensional reality where energy flows occur not only within each plane, but between them and in all directions. This integrated reality is an energetic ecosystem, to which we aim to provide balance and sustainability. Once understood this, it is also easy to understand that the mechanisms of rebalancing go through the transfer of the energy resources that are left over in one part of the ecosystem to another part of it where energy is demanded, by the capacity of change of the energy configuration of all the Ecosystem, by the correction of the imbalances and by the symbiotic action between the different systems and subsystems . If we look at the context for opportunities, we see that the two determinants of global development in the coming years are demographic growth and climate change. There is a link between population growth and urbanization in the world in the coming decades, the exponential development of urban areas and the phenomenon of emergence of new megalopolises. The harmonious development of cities is linked to a balance between its density and its complexity . On the other hand, the progressive recovery of urban space for its civic use raises a need to orientate the field of development of the network of infrastructures, services and endowments, towards the underground space. The field of opportunities emerging from integrated management  of underground resources includes the use of subsoil Energy resources for energy capture, exchange and storage. Geothermal exchange allows the inertial use of ground and the built mass buildings and infrastructures, for the accumulation of large quantities of thermal energy with low power and moderate temperature bands, is therefore a Means to accumulate the generated thermal energy and often considered residual, by industrial systems and urban infrastructures and to propitiate its reuse with very low costs, and very long life cycle. The accumulation of thermal energy in the field can also be applied to integrated and distributed systems of solar thermal capture, and solar photovoltaic
[en] It is evident that dampness inside buildings favors the emergence of diverse pathologies and can end up causing health problems in their occupants . Dampness is not due to a single cause but has different origins and different forms of appearance : capillarity, excessive water in construction, condensation, rain, escapes, leaks, etc. The use of impervious materials is presented as one of the solutions to the problem. Gypsum, one of the most commonly used traditional materials in construction , is known for its avidity for water and the negative effects water causes in it; On the contrary, plastic materials are water-resistant. That is why in this study, the improvement of the properties of gypsum compared to water is analyzed through the incorporation of plastic waste in its matrix. In the experimental process, plaster specimens were made with a mass ratio of water / plaster 0.8. Plastic residue from the recycling cable process with a maximum particle size of 3 mm was added to these plaster specimens in proportions of 50% -60% -70% on the mass of the plaster. To observe their performance in contact with water they were subjected to the following tests: water absorption by capillarity , water vapor permeability , damp chamber , water-stove cycles  and total absorption of water. . In all cases, the capacity to retain and absorb water decreased significantly, maintaining the hygrothermal properties of gypsum at acceptable levels according to EN ISO 13788: 2016  for residential buildings. Therefore, it is considered a good solution to minimize the emergence of dampness in buildings without affecting the regulation of relative dampness in rooms.
[en] In the extensive world of construction materials, plaster is one of the most present in day-today construction. Due to its low cost of obtaining - it is obtained directly from nature and does not need hardly any treatment - its aesthetic finish and its handling and putting into work, it becomes one of the most used resources as interior finishes, linings and partitions in building. In a historical moment in which both properties, thermal comfort and the sustainability in terms of the use of materials and resources begin to be important, it is essential to think of new constructive solutions that respond to these needs. Research is beginning to be observed to verify the mechanical characteristics of recycled building plasters, with the intention of being able to reuse these materials with high reliability and thus reduce the energy expenditure produced in obtaining this material . Another branch of the investigation is the addition of fibers to these mortars. The addition of fibers, both natural and artificial, to construction elements such as concrete or plaster to alter their qualities and improve any of them is a constant object of study. In this way, Iucolano , have already experimented with the addition of fibers, specifically with hemp, to improve the mechanical properties of the plaster. In turn, they discovered that thermal properties were also improved with the addition of these fibers. In addition to natural fibers, the addition of porous materials to the plaster makes it improve its acoustic and thermal insulation, thus allowing it to be used in sites with specific requirements...
[en] Aiming to determine the BaSO4, utilized as shielding against ionizing. The type and quantity of aggregate in the concrete are important components for radiation protection properties of concretes. The X-ray spectrum was measured with a cadmium zinc telluride detector (CdZnTe). The samples were irradiated with x-rays with potentials in the radiation qualities ISO N60, N80, N110 and N150. The analyses proved to be effective and led to the identification of the total composition of samples in 95.88%. The results obtained show that the barium content is higher than the sulphate content in the BaSO4 compound regardless of its origin. (author)
[en] The paper presents the results of studies on preparation and structure of water- resistant gypsum compositions using mineral materials and modifying additives as a filler. Using gypsum-based compositions and fuel slags, fine-grained concrete and wall blocks were obtained, characterized by ρ = 1750-1850 kg / m3, compression testRcompr= 5-8 MPa, frost resistance 10 cycles, and thermal conductivity λ = 0.41-0.42 W / (m • K). (author)
[en] In this research, the ability of a hybrid model, which is integrating the firefly algorithm with the multilayer perceptron (MLP-FFA), is investigated for prediction of soil salinity (EC) using remote sensing and topography data in Miandoab city, northwest of Iran. Some important variables including the salinity ratio (SR), slope, ratio vegetation index (RVI), normalized differential vegetation index (NDVI), gypsum index, soil-adjusted vegetation index (SAVI), elevation and normalized difference salinity index (NDSI) are used as inputs of the model, while the EC is the output variable. The data consist of 80 soil samples. The estimates provided by the MLP-FFA model are compared with the standalone MLP model based on the coefficient of determination (R2), root mean square error (RMSE), mean absolute error (MAE), Nash–Sutcliffe coefficient (ENS), Willmott’s Index of agreement (Wi) and percentage peak deviation (Pdv). The obtained results showed more precise estimations of the MLP-FFA than the MLP model with R2, MAE, RMSE, ENS, Wi and Pdv values of 0.641, 1.195, 1.672, 0.626, − 0.247 and 4.603, respectively, in training phase, while in the testing phase these values were equal to 0.662, 0.439, 0.538, 0.566, − 0.15 and − 32.013, respectively. Therefore, the results specified that the developed MLP-FFA model can be selected as an efficient technique over the MLP model for accurate prediction of EC.
[en] The recycling of civil construction waste gypsum has been the subject of studies due to the nonexistence of economically viable technologies or applications that would allow it to be recycled. However, studies indicate that the material setting time reduces after recycling, generating more waste, but the cause of the phenomenon is not known. In-situ XRPD monitoring of plasters' hydration in their commercial form and after laboratory recycling process is carried out to verify both reactivity and hydration process. The samples are characterized by specific surface area, microporosity, and consistency tests. Sequential and parametric Rietveld refinements are employed to determine the weight fractions of calcium sulfate-based compounds present in the materials as a function of time. The increase in the consistency of the recycled plaster is not only associated with the increase of microporosity and specific surface area but also to the instant formation of gypsum as soon as the material comes into contact with water. These data also confirm the increase in the kinetic activity values calculated from the results of temperature kinetics tests, proving that the formation of hydrated compounds is much faster for the recycled plaster, which is associated with the increase of water contact area. (author)
[en] As you know, the concentration of radon in buildings built with different building materials also varies. Wood and concrete houses can be considered satisfactory in terms of radon concentration. Thus, widespread construction materials such as trees, bricks and concrete produce relatively small radon radiation.In wooden houses, this radiation is minimal (up to 0.5 mZv / year), while brick and reinforced concrete houses are slightly larger (up to 1.5 mZv / year).It should be noted that the increase in radon concentrations inside buildings is not only building materials, but also soil below the building.Therefore, despite the fact that wood is less radiant than other building materials, in some cases wooden homes have more radon levels than brick houses.For example, studies in Norway have shown that concentration of radon in wooden houses is higher than that of brick houses, and it is found that these trees are usually smaller floors and closer to the radon source.During the development of phosphorus sources, calcium-silicate slag is formed as a by-product.This slag, which has long been used as a building material and concrete component in North america (Idaho and Florida) and Canada, has been found to have a sufficiently high radioactivity.Phosphorus mining uses a different technology to produce additional products called phosphogips.
[en] Over the past few years, various materials used in masonry, such as lead, concrete, ceramic blocks and brick, have been studied for use as shielding against ionizing radiation from different energies in radioactive facilities. In the area of diagnostic radiology, lead and barite are the most used materials as shielding, but for bundles of low energy X radiation, as in mammography and dentistry, plaster material can be used, as affirmed by the National Council on Radiological Protection and Measures through its report number 147 (NCRP Report Nº 147). This work developed plaster phantoms as well as gypsum & barite mixing with plate formats with a 10 x 10 centimeter area, aiming to characterize physico-chemically and verify the feasibility of using these materials as shielding against low-energy X-ray radiation, using standard dental and mammographic X-ray bundles in metrology laboratories. From the irradiation, it was possible to obtain the transmissions curves, to discover the Half Value Layers (HVL) and the Tenth Value Layers (TVL), as well as to acquire the different spectra for each material. The gypsum & barite mixing material had a better shielding response compared to pure gypsum material, however both can be considered as good attenuators against low energy X radiation. (author)