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Introduction: Concrete sealing blocks are not only used in Brazil but worldwide. T he knowledge of the material properties in the presence of moisture becomes necessary to study the durability of buildings. Methods: An experimental study was carried out in order to analyse the effect of contact area on the capillary absorption coefficient of concrete samples used in sealing blocks, according to several standards: NBR 9779 (2012), EN 1015-18 (2002), ISO 15148 (2002) and ASTM C1794 (2015). Two types of specimens were analysed; monolithic samples and samples with a perfect contact interface. The monolithic samples were also subjected to axial and radial compression in order to enhance the capacity of masonry. Results: The experimental results for the samples with perfect contact interface indicate that the water absorption before the interface presents similar behaviour to the monolithic samples. However, it is possible to observe a reduction of the absorption rate when water reaches the interface due to the hygric resistance. In other words, the moisture transport is significantly retarded by the existence of an interface, i.e., the discontinuity of moisture content across the interface indicated that there was a difference in capillary pressure across the interface. Also, the interface contact area does not greatly influence the water-resistance values. Conclusion: Finally, the Hygric Resistance values (HR), in multilayer building components, with perfect contact interface are calculated using the “knee point” methodology.

Due to the early deterioration of pile cap foundations in residential buildings and bridges in the metropolitan region of Recife, several samples taken from a pile cap block of a residential building, built about ten years ago, were studied. The problem of the extensive cracking in the pile cap foundation had its origin in the delayed ettringite formation, possibly due to a high heat of hydration due to the concreting of the large volume of concrete. In this work, laboratory tests were performed to evaluate the transport properties of concrete samples, as well as their physical and chemical composition using advanced analyses. The tests performed in the experimental campaign were the apparent porosity, gas permeability, scanning electron microscopy, X-ray diffraction and Raman spectroscopy. The presence of crystalline products of the alkali-aggregate reaction was proven through physical–chemical analyses, such as Raman spectroscopy and EDS. Moreover, the ettringite crystals were observed in XRD standards, SEM images and in the chemical composition of EDS. The porosity showed a high value (between 9 and 10%), as well as the concrete permeability (10–16 m2 and 10–15 m2), determining the negative influence of ISR on the transport properties. Therefore, the methods used have proven to be effective in understanding the problem encountered and have the potential to be used in the design and execution of pile cap blocks.

The knowledge of moisture transfer in multi-layered building materials and components using numerical simulations is fundamental to predict the behaviour of that building materials and components when in contact with moisture and to avoid some possible future pathology guarantying a correct performance.This paper describes a comparative analysis of experimental values of Hygric Permeance (HP) obtained by water absorption curves and gamma-ray attenuation profiles, for perfect contact interface.

This paper has the aim to evaluate the mechanical performance of gypsum walls. It was carried out a laboratory experimental characterization of the gypsum materials properties and different waterproofing contents, which determine their mechanical behaviour, by flexural and compressive strength tests, tensile adhesion and surface hardness. The wall system performance was also evaluated in terms of its water-tightness.The results showed that the samples with lower water repellent additive content present higher compressive strength values and the gypsum walls tested achieved the minimum level of performance (Level M).

This work discusses the effects of soluble mineral salts on ceramic brick masonry walls at Petrolina, Pernambuco, Brazil, located 780 km from the ocean. To understand this phenomenon, a mapping of the pathologies originating from the effects of soluble mineral salts in Petrolina was carried out and wells were implemented to monitor the underground water supply in five points considered to be where the most frequent occurrence of the phenomenon takes place. Samples of soil, groundwater, bricks affected by the phenomenon and the level of chloride in the atmosphere of these localities were collected and analysed in the laboratory in order to characterize their properties. The results obtained indicate that the building pathological manifestations present in ceramic block walls, located in the study areas, are strongly correlated with the high content of soluble salts observed in the soil and groundwater samples collected than by the amount of chloride content in the atmosphere soluble salt levels. Clay sands are a type of soil more prone to underground water runoff and, because of this feature, provide a more favourable environment for rising moisture that transports soluble mineral salts to the masonry walls accelerating their degradation process.

Limpets are one of the most successful intertidal algal grazers in the north‐eastern Atlantic. They provide valuable ecosystem services, playing a pivotal role in maintaining rocky shore ecological balance and have an important economic value, being subject to high levels of exploitation in several oceanic archipelagos. Limpets represent one of the most profitable economic activities of small‐scale fisheries in the Madeira archipelago. However, limpets are extremely vulnerable to anthropogenic impacts, such as overharvesting, habitat fragmentation, and pollution. The protection effects and the effectiveness of marine protected areas (MPAs) on the population dynamics of two historically highly exploited limpet species, Patella aspera and Patella candei, were analysed through a comparative study of size, reproduction, and biomass in the Madeira archipelago. The effects of protection from MPAs on limpet populations resulted in a differential increase on size at first maturity, shell size, and capture per unit effort according to the degree of protection. Old and enforced MPAs showed the best‐preserved limpet populations in the study area, and both variables (age and enforcement) best explained the observed variability among the MPAs studied. A thorough and multidisciplinary study is necessary to obtain a reliable picture of commercial stocks of the two targeted species (P. aspera and P. candei). Genetic analysis and studies on the food source of limpets may shed light to develop integrative conservation strategies.

Several artisanal fisheries target deepwater species. These stocks are highly sensitive to overfishing because of their slow growth and late maturation. This vulnerability is higher if species concentrate during spawning season in coastal areas, as occur with scabbardfish (Aphanopus spp.). In this paper, we explore if two Aphanopus species (A. carbo and A. intermedius) that coexist show migration patterns to coastal areas during spawning. We analysed specimens of both species throughout 4 years (2014–2017) in a weekly basis and compare morphological parameters with the distance of the coast (coastal (12 n.m.)). Both species showed coastal patterns of migration during the spawning season (October–December), with 65.90% of total specimens of A. carbo and 51.60% of A. intermedius being caught at

Concrete, when exposed to high temperatures, presents important changes in its properties of strength and deformation and, in extreme situations, these alterations can constitute risks to the integrity and the safety of the structures. This work presents extensive campaign with 70 cylindrical specimens and seven different mixture proportions: two of mortar and five of concrete, to analyze the propagation profile of longitudinal and transverse ultrasonic waves in concrete cylindrical specimens, associating the variation of the ultrasonic pulses with the level of compression stresses and the degree of damage imposed by high temperature. The compressive strength was within the range of 32 and 64 MPa and the specimens were exposed to temperatures of 250°, 300° and 350°C. The results indicate that longitudinal and transverse ultrasonic waves can be successfully applied in the evaluation of diffuse damage cause by uniaxial compression load and exposure to high temperatures.

The future of construction will be directly connected with additive manufacturing (AM). It is easy to see the lack of consistency between jobs, labour inefficiency, schedule delays, delays on material delivery, exceeding budget projections and high percentage of material waste. Over the years, additive manufacturing has been a constant topic of discussion, in order to understand the limitations, applications and the overall impact on the cost of construction. In this work it is intended to present/discuss opportunities and challenges and the potential of AM to revolutionize the industry.

The main goal of this work is the analysis of the thermal and environmental benefits of 3D printing on building construction. Present literature reports a considerable number of benefits for 3D printing, namely reduction of material use, lower operational costs and time saving. Authors also mention design freedom, higher efficiency, productivity and quality. This work presents the most important advances in 3D printing in civil engineering, specifically, a critical review of the thermal and environmental benefits of 3D printing on building construction. The limitations of construction 3D printing with focus on large-scale applications, technology costs, mix development and optimisation and thermal behaviour will be, also, defined.

This work presents the study of the influence of the incorporation of cellulose fibres in mortars, as waste recycling alternatives in the building materials construction production, in favour of sustainability policy. Building construction is an area of great potential to absorb waste in its productive chain, producing alternative materials and thus reducing the environmental impact with the reuse of by-products or waste from other industries and its own chain. The main objective of this work is to investigate the effect of the addition of recycled paper cement mortar cellulose fibres (in the amount of 10% and 15% of the total weight) on composite mixture in order to analyse the resulting properties in fresh state (consistency index and density) and for a hardening of 7 days (compressive and flexural strength). The composite mixtures were prepared with cement, hydrated lime mortar and sand with a ratio of 1:1:6, by weight, and a water/agglomerates rate equal to 0.60. A comparison with the reference sample showed a decrease of the compressive and flexural strength proportionally with the addition of recycled paper cellulose fibre, however, as the amount of cellulose fibre is higher, the tenacity and the deformation increase. Thus, even supporting lower load bearing, the use of the cellulose fibres provides a greater bearing capacity to deformations required for the mortar, particularly in post crack stage, absorbing more energy before rupture.

In this work, it was analyzed in detail the problem of the extensive cracking in the pile cap foundation originated by the delayed ettringite formation, possibly from a high heat of hydration coming from the concreting of the large volume of concrete. Laboratory tests were performed to evaluate the transport properties of concrete samples, as well as their physical and chemical composition using advanced analyses. The tests performed were apparent porosity, gas permeability, scanning electron microscopy, X-ray diffraction and Raman spectroscopy. The presence of crystalline products of the alkali-aggregate reaction was proven through physical–chemical analyses, such as Raman spectroscopy and EDS. As well as the ettringite crystals found in XRD standards, SEM images and the chemical composition of EDS. The porosity showed a high value (between 9 and 10%), as well as the concrete permeability (10–16 and 10–15), determining the negative influence of ISR on the transport properties. Therefore, the methods used have proven to be effective in understanding the problem encountered and have the potential to be used in the design and execution of pile cap blocks.

The present study was conceptualized to study the muraenid species (moray eels) occurring around the volcanic archipelagos of the Azores, Madeira, Selvagens, Canary and Cabo Verde islands (eastern-central Atlantic). The biogeographic patterns of these species were analysed and compared. We then hypothesized that this fish family is an ideal group for testing at small-scale the coherency of Macaronesia and its direct biogeographic units: i.e. the Azores, Webbnesia and Cabo Verde, as proposed in recent scientific literature. Additionally, this paper provides for the first time separate fishery statistics for this group in the region that were analysed to contrast the biogeographic results., Este trabajo fue ideado para estudiar las especies de Muraenidae (morenas) presentes en aguas de los archipiélagos volcánicos de Azores, Madeira, Salvajes, Canarias y Cabo Verde (Atlántico centro-oriental), cuyos patrones biogeográficos fueron analizados y comparados. La hipótesis de partida fue que esta familia ictiológica es un grupo ideal para verificar, a pequeña escala, la coherencia de la Macaronesia y sus unidades biogeográficas directamente relacionadas -i.e. Azores, Webbnesia y Cabo Verde- propuestas en la literatura reciente. Además, este estudio proporciona, por primera vez, estadísticas pesqueras separadas de este grupo en la región que fueron analizadas para contrastar los resultados biogeográficos.

This work aims to study the drying of clay ceramic materials with arbitrary shapes theoretically. Advanced phenomenological mathematical models based on lumped analysis and their exact solutions are presented to predict the heat and mass transfers in the porous material and estimate the transport coefficients. Application has been made in hollow ceramic bricks. Different simulations were carried out to evaluate the effect of drying air conditions (relative humidity and speed) under conditions of forced and natural convection. The transient results of the moisture content and temperature of the brick, and the convective heat and mass transfer coefficients are presented, discussed and compared with experimental data, obtaining a good agreement. It was found that the lower the relative humidity is and the higher the speed of the drying air is, the higher the convective heat and mass transfer coefficients are at the surface of the brick and in the holes, and the faster the moisture removal material and heating is. Based on the predicted results, the best conditions for brick drying were given. The idea is to increase the quality of the brick after the process, to reduce the waste of raw material and energy consumption in the process.

Aims Rising sea-level following the Last Glacial Maximum lead to fragmentation of coastal limpet populations between islands of the Archipelago of Madeira. This fragmentation is reinforced by recent heavy exploitation reducing effective population size on Madeira Island. We use the limpet P. aspera to understand how the role of processes at different time scales (i.e. changes in the sea level and overexploitation) can influence the genetic composition of an extant species, relating these processes to reproductive phenology and seasonal shifts in ocean currents. Location Madeira Island, Porto Santo and Desertas (Archipelago of Madeira, NE Atlantic Ocean). Taxon The limpet Patella aspera. Methods Twelve microsatellite genetic markers were used. A power analysis was used to evaluate the power of the microsatellite markers to detect a signal of population differentiation. Long-term past migrations were assessed using a Bayesian Markov Montecarlo approach in the software MIGRATE-n to estimate mutation-scaled migration rates (M = m/μ; m, probability of a lineage immigrating per generation; μ, mutation rate). Two scenarios were evaluated using an Approximate Bayesian Computation (ABC) in the software DIYABC 2.1 (i) Scenario 1: considered a population scenario from a reduced Ne at time t3 to a higher Ne at time t2; and (ii) Scenario 2 considering a reduction of Ne from a time t3 to a time t2. Results Colonization of the archipelago by Portuguese settlers six centuries ago probably led to an important decrease in the genetic diversity of the species (Ne). Contemporary gene flow strongly support a pattern of high asymmetric connectivity explained by the reproductive phenology of the species and spatio-temporal seasonal changes in the ocean currents. Spatio-temporal reconstructions using Bayesian methods, including coalescent and Approximate Bayesian Computation (ABC) approaches, suggest changes in the migration patterns from highly symmetric to highly asymmetric connectivity with subtle population differentiation as consequence of post-glacial maximum sea level rise during the Holocene. Main conclusions Our results suggest that anthropogenic activity could have had serious effects on the genetic diversity of heavily exploited littoral species since the end of the Pleistocene, probably accelerating in recent years.

The understanding of the mechanical fixation behavior of coatings is crucial for a better comprehension of the bonding systems, especially at the interface between the mortar and the substrate. Physical adherence is related, among other things, to the contents of the materials used in the roughcast and mortar coatings, due to the colloidal water penetration into the pores of the substrate. This work evaluated the influence of different lime solution additions replacing the kneading water in the preparation of roughcast and mortar coatings. Two types of substrates were investigated:ceramic bricks and concrete blocks. Three wall masonry panels were constructed, with dimensions of 220 × 180 cm2, one of concrete block and two of ceramic bricks, followed by the application of roughcast and mortar coating with an average thickness of 5 mm and 20 mm, respectively. Direct tensile bond strength tests were performed and the results, with a 95% confidence level, showed that substrate ceramic and treatment in the roughcast exhibited a better behavior regarding the distribution of the tensile bond strength of the tested specimens. However, no significant differences of the amount of addition used (0%, 5%, 10% and 15%) on the tensile bond strength were observed.

Commonly based on the liquid diffusion theory, drying theoretical studies in porous materials has been directed to plate, cylinder, and sphere, and few works are applied to non-conventional geometries. In this sense, this work aims to study, theoretically, the drying of solids with oblate spheroidal geometry based on the thermodynamics of irreversible processes. Mathematical modeling is proposed to describe, simultaneously, the heat and mass transfer (liquid and vapor) during the drying process, considering the variability of the transport coefficients and the convective boundary conditions on the solid surface, with particular reference to convective drying of lentil grains at low temperature and moderate air relative humidity. All the governing equations were written in the oblate spheroidal coordinates system and solved numerically using the finite-volume technique and the iterative Gauss–Seidel method. Numerical results of moisture content, temperature, liquid, vapor, and heat fluxes during the drying process were obtained, analyzed, and compared with experimental data, with a suitable agreement. It was observed that the areas near the focal point of the lentil grain dry and heat up faster, consequently, these areas are more susceptible to the appearance of cracks that can compromise the quality of the product. In addition, it was found that the vapor flux was predominant during the drying process when compared to the liquid flux.

Studies on microbial communities are pivotal to understand the role and the evolutionary paths of the host and their associated microorganisms in the ecosystems. Meta-genomics techniques have proven to be one of the most effective tools in the identification of endosymbiotic communities of host species. The microbiome of the highly exploited topshell Phorcus sauciatus was characterized in the Northeastern Atlantic (Portugal, Madeira, Selvagens, Canaries and Azores). Alpha diversity analysis based on observed OTUs showed significant differences among regions. The Principal Coordinates Analysis of beta-diversity based on presence/absence showed three well differentiated groups, one from Azores, a second from Madeira and the third one for mainland Portugal, Selvagens and the Canaries. The microbiome results may be mainly explained by large-scale oceanographic processes of the study region, i.e., the North Atlantic Subtropical Gyre, and specifically by the Canary Current. Our results suggest the feasibility of microbiome as a model study to unravel biogeographic and evolutionary processes in marine species with high dispersive potential.

Detailed information about concrete behavior in real structures is an important issue in controlling its performance during its service life, and the use of embedded sensors to obtain desired information such as temperature, onset of the cracking process and evolution of strains, has gained the attention of the building concrete industry. Data obtained using this technology can provide valuable information for decision making about the need for corrective interventions that can ensure the integrity and safety of concrete structures for long period of time. This paper presents a review of the current state-of-the-art of embedded fiber optic sensors used to assess concrete information of a wide range of aspects, comprising: existing alternative technologies, characteristics and advantages, practical applications and future developments. Complementarily, the work presents preliminary results of the use of fiber optic sensors to automatically and continuously perform expansion readings of AAR in concrete elements that facilitate both the storage—with elimination of the usual interruptions for manual readings—and the availability of continuous results of expansion data that are not possible to obtain with usual AAR tests code reading recommendations.

After intensifying the knowledge of hygric permeance (HP) in multi-layered test samples, which were subjected to the imbibition process, a significant set of HP values (with different interface types) was experimentally achieved. This was done in order to develop a new model which allows estimating more correctly the hygric permeance. The idea is predicts the HP with several scenarios, i.e., different interfaces (perfect contact, hydraulic contact and air space interface), interfaces heights and materials studied, in the attempt to estimate the HP without the need to resort to the measurement by the experimental route in the attempt to estimate the HP without the need to resort to the measurement by the experimental route and even with possible measurement, generator automatic calculation (without human opinion/criteria). In this paper, the Hygric Permeance will be calculated by two different methods, gravimetric and gamma ray methods, and a new methodology proposes. The maximum flows transmitted were determined by the slope of the mass variation per contact area in function of the time involved. When having interface, the calculations admit that the first layer is saturated and that all the increased weight stems becomes from the relative humidity that penetrates the interface. The new methodology proposed is analysis of the prevision mathematical model that describes the mass variation per contact area in function of the time, after the “knee point”. This work it is the first attempt to provide a set of values that refer from hygric permeance in masonry of building walls, these being random values experimentally determined.

Mortar bond covering systems are multilayered and applied to a base, composed of render mortars (stucco, plaster) followed by some decorative element for a finishing touches (paint, ceramic plate, ornamental stones, etc.). In order to homogenize the characteristics of the base material and to increase the bond with the render mortar, it is a common practice to apply some type of preparation, either an even, smooth solution such as wetting the walls, or roughened solution utilizing roughcast. Studies have shown that the presence of calcium ions in ceramic bases results in the formation of a more dense crystalline structure at the interface, which culminates with higher mechanical bond strength. In this light, the present study presents an experimental investigation, the purpose of which is to evaluate, in a comparative way, the direct tensile strength of bond of a mortar coating applied to the same base, preceded in its application by five different preparation techniques. It can be concluded from this study that the preparation of the mortar base is of fundamental importance for bonding strength and, therefore, the addition of a lime solution to the roughcast is economically feasible and a satisfactory alternative in order to obtain positive results in environments where bond strength is critical.

The preservation of artefacts in museum collections is profoundly affected by fluctuations in temperature and, especially, relative humidity (RH). Since the late nineteenth century, many st...

This work presents an extensive experimental characterization of two different ceramic brick blocks with hydraulic contact interface (cement mortar or lime mortar), at different heights, during the...

The phenomena of transport in porous media arises in many diverse fields of science and engineering, ranging from agricultural, biomedical, building, ceramic, chemical, and petroleum engineering to food and soil science. Several authors provide an extensive description of the problems involving porous media. For building engineering, obtaining a good understanding of moisture transport in building envelopes is becoming one of the most important tasks. In the last few decades, many studies investigating moisture transport in building envelopes have been published, which have helped to improve overall building envelope design. This work presents a brief review of these studies.

Topshells play a pivotal role in intertidal rocky ecosystems and are adapted to harsh thermal and hydric stress. Phorcus sauciatus, a common grazer in the Macaronesian region (Madeira and the Canaries), has rarely been studied due to its restricted geographic distribution compared with Phorcus lineatus. Monthly samples were taken throughout 2017 to analyse biological parameters and evaluate the harvesting effect on the stocks of this species in Madeira. Individuals of the first age classes (−1, corresponding to a Y/R of 0.023 g. Currently, Phorcus sauciatus seems to be moderately exploited in Madeira, but urgent conservation measures, such as a landing obligation, the establishment of a minimum catch size of 15 mm length, and a closed season (February–May), are warranted to preserve stocks of this species in the medium to long term.

This chapter aims to present a theoretical study of the fluid flow in porous media, with particular reference to manufacturing of polymer composites reinforced with fibers via resin transfer molding process. The mass and momentum conservation equations, including the effect of resin sorption by the fibers, and Darcy's law, are presented, and the analytical solution of the governing equation is obtained via method of separation of variables. Predicted results of the flow front, velocity, volumetric flow rate and pressure fields of the resin inside the model, during the injection process, are presented, and the effects of the injection pressure, resin viscosity and sorption term, are also analyzed.

Early deterioration of reinforced concrete foundations has been often reported in recent years. This process is usually characterized by an extensive mapping cracking process on concrete surfaces that results from several types of Internal Swelling Reaction (ISR). In this paper, a real case study of a tall reinforced concrete building with a severe deterioration process installed in its deep foundations is discussed. Laboratory tests were performed in concrete drilled cores extracted from a deep pile cap block 19 years after the beginning of construction. Tests to assess the compressive strength, the static and the dynamic modulus of elasticity, the gas permeability, and electron microscopy scanning to find out the primary mechanism responsible for the deterioration observed during in situ inspections. Chemical alterations of materials were observed in concrete cores, mainly due to Delayed Ettringite Formation (DEF), which significantly affected the integrity and durability of the structure. Dynamic modulus of elasticity showed to be a better indicator of damage induced by ISR in concrete than compressive strength. Procedures to strengthen the deteriorated elements using prestressing proved to be an efficient strategy to recover the structural integrity of pile caps deteriorated due to expansions due to ISR.

Wastewater from the oil industry can be considered a dangerous contaminant for the environment and needs to be treated before disposal or re-use. Currently, membrane separation is one of the most used technologies for the treatment of produced water. Therefore, the present work aims to study the process of separating oily water in a module equipped with a ceramic membrane, based on the Eulerian–Eulerian approach and the Shear-Stress Transport (SST k-ω) turbulence model, using the Ansys Fluent® 15.0. The hydrodynamic behavior of the water/oil mixture in the filtration module was evaluated under different conditions of the mass flow rate of the fluid mixture and oil concentration at the entrance, the diameter of the oil particles, and membrane permeability and porosity. It was found that an increase in the feed mass flow rate from 0.5 to 1.5 kg/s significantly influenced transmembrane pressure, that varied from 33.00 to 221.32 kPa. Besides, it was observed that the particle diameter and porosity of the membranes did not influence the performance of the filtration module, it was also verified that increasing the permeability of the membranes, from 3 × 10−15 to 3 × 10−13 m2, caused transmembrane pressure reduction of 22.77%. The greater the average oil concentration at the permeate (from 0.021 to 0.037 kg/m3) and concentrate (from 1.00 to 1.154 kg/m3) outlets, the higher the average flow rate of oil at the permeate outlets. These results showed that the filter separator has good potential for water/oil separation.

This work aims to study the influence of using construction and demolition waste in the replacement of coarse and fine aggregate to produce recycled aggregate concrete (RAC). A moderate compressive strength concrete made with usual fine and coarse aggregate was used as a benchmark material. Compressive and split tensile tests were performed using 120 cylindrical concrete specimens with 150 mm diameter and 300 mm length. Four-point flexural tests in reinforced beams made with conventional concrete and RAC were performed. The results obtained showed that the use of recycled fine aggregates, in both percentages of substitution investigated—50% and 100%—did not generate any deleterious influence on the values of compressive strength and split tensile strength of the RACs produced. Tin fact, the mechanical strengths of RACs produced with recycled fine aggregate were equal or higher than those from the reference concrete. The same behavior was not observed, however, when the recycled coarse aggregate was used. For this case, decreases in concrete mechanical strengths were observed, especially in compressive strength, with values around 35% lower when compared to the reference concrete. Tensile mechanical tests results confirmed the excellent behavior of all RACs made with replacement of usual fine aggregates by recycled. Bending tests performed in reinforced RAC beams had as objective to evaluate the deformation profile of the beams. The obtained results showed that RAC beams with full replacement of usual fine aggregate by the recycled aggregates have presented little changes in the global behavior, an aspect that encourages its use.

The work presents the results of an experimental campaign carried out on concrete elements in order to investigate the potential of using artificial neural networks (ANNs) to estimate the compressive strength based on relevant parameters, such as the water–cement ratio, aggregate–cement ratio, age of testing, and percentage cement/metakaolin ratios (5% and 10%). We prepared 162 cylindrical concrete specimens with dimensions of 10 cm in diameter and 20 cm in height and 27 prismatic specimens with cross sections measuring 25 and 50 cm in length, with 9 different concrete mixture proportions. A longitudinal transducer with a frequency of 54 kHz was used to measure the ultrasonic velocities. An ANN model was developed, different ANN configurations were tested and compared to identify the best ANN model. Using this model, it was possible to assess the contribution of each input variable to the compressive strength of the tested concretes. The results indicate an excellent performance of the ANN model developed to predict compressive strength from the input parameters studied, with an average error less than 5%. Together, the water–cement ratio and the percentage of metakaolin were shown to be the most influential factors for the compressive strength value predicted by the developed ANN model.

The environmental impact of cement production was increased significantly in the last years. It is estimated that for each ton of cement produced, approximately one ton of carbon dioxide is emitted, divided into: decarbonation (50%), combustion in the clinker furnace (40%), transport of raw materials (5%) and electricity (5%). From a world perspective, green strategies have been advanced in order to reduce the environmental impact of the cement production. In this sense, the sugar cane bagasse ash is a by-product resulted from boilers of sugar and alcohol factories. This material, composed mainly of silica, can be used as a mineral admixture in mortar and concrete, with great economic and environmental advantages. This work intent to collaborate for the partial substitution of Portland cement by sugar cane bagasse (SCB), in order to reduce the consume of clinker by volume of concrete, which is the responsible for the high emission of CO2 to the atmosphere. For this, an experimental campaign was carried out with cementitious pastes to evaluate the changes in their properties, namely the durability, due to the use of SCB ash. Finally, it could be concluded that concrete structures with sugar cane bagasse ash presented an interesting behavior and, in terms of durability, the samples containing 15% of the ash of sugarcane bagasse showed good results, being important to highlight the need and interest of doing further research on the topic.

Acoustic forecasting models from computational simulation (SC) has been the tool used to evaluate the acoustic behavior of the building, even before the work is done, thus enabling the reduction of post-adaptation costs. This research aims to evaluate the reliability of computational simulation by analyzing data from simulations and field measurements (MC) of 14 case studies, in relation to horizontal partition systems (SVH). For the 228 SVH data, of which 116 were for SVH-RA and 102 for SVH-RI, the comparative study showed 38% acceptability between SVH-RA measurement and simulation; and 46% for SVH-RI. This acceptability refers to the values within the ±2 dB range of the aforementioned uncertainty. The data also showed variation between SC and MC, sometimes presenting larger SC, sometimes larger MC. The predicted hypothesis was that SC would always be higher due to the ideal conditions of the simulation, which do not occur in the field. However, where situations of MC greater than SC occurred, it was deduced that deciding on the simulation means choosing to work in favor of safety, since the minimum level of the standard is projected and better results are obtained in the field. It was also verified, through variation of the input data, that the fidelity with the technical specification of the designed systems reproduces reliable values, and the opposite, results in doubtful and discrepant data. In general, the results of the comparative analysis point to the use of computer simulation as positive, since part of the percentage that is not acceptable in this study represents doubtful measurements, and therefore, the simulation is an effective predictive tool and useful in the search for acoustic quality in residential buildings.

This research aims to evaluate the reliability of computational simulation by analyzing data from simulations and field measurements (MC) of 14 case studies, in relation to internal vertical partition systems (SVVI). Comparative analysis of 75 SVVI results, SC and MC data showed that more than 50% of the simulation data showed values compatible with the in-field measurement, in the sense that they were considered potentially equal, taking into account the uncertainty of the predicted field measurement. in the evaluation methodology contained in the standard, in the order of ±2 dB. This acceptability refers to the values within the ±2 dB range of the aforementioned uncertainty. The data also showed variation between SC and MC, sometimes presenting larger SC, sometimes larger MC. The predicted hypothesis was that SC would always be higher due to the ideal conditions of the simulation, which do not occur in the field. However, where situations of MC greater than SC occurred, it was deduced that deciding on the simulation means choosing to work in favor of safety, since the minimum level of the standard is projected and better results are obtained in the field. It was also verified, through variation of the input data, that the fidelity with the technical specification of the designed systems reproduces reliable values, and the opposite, results in doubtful and discrepant data. In general, the results of the comparative analysis point to the use of computer simulation as positive, since part of the percentage that is not acceptable in this study represents doubtful measurements, and therefore, the simulation is an effective predictive tool and useful in the search for acoustic quality in residential buildings.

Regardless of the construction processes or employed materials, the NBR 15575 (2013) defines objectives, requirements and methods for assessing the behaviour in use performance of accommodations. Therefore, the influence of the coating layers on the performance of construction systems is an essential parameter to assess the use of materials and elements of the systems, in order to make the project feasible, not only economically, but also technically. Through numerical simulations based on a defined reference model for the study, the present work study the influence of different layers of floor, roof and, internal and external wall systems, on the acoustic performance. Finally, analysing the results, for the reference model used, identified the materials and elements with the greatest influence on acoustic performance of the facade—function especially of the external windows; acoustic performance of the floor system—mainly influenced by the thickness of the structural element and the use of ceiling and acoustic blanket; acoustic performance of internal walls—typology of the structured element of the wall and thickness.

In determining the temperature field generated within a room subjected to exterior daily variation of temperatures and solar radiation, and in view of the difficulty (or even impossibility) of obtaining analytical solutions for the descriptive differential equations of the phenomenon in most practical applications, numerical tools are used. The choice of the Finite Element Method (FEM) as a numerical methodology for solving the thermal problem associated with heat transfer in current building materials and phase change materials makes sense, as it is a well-known technique, generalize and dominated, however, still little applied to the domain of building physics. The proposed numerical simulation was performed with three main objectives: (i) the numerical resolution of the mathematical problem of heat transfer in phase change materials using the finite element method, in a three-dimensional (3D) analysis; (ii) the validation of numerical simulation capability by comparing the results obtained experimentally with the results obtained numerically; (iii) the evaluation of some of the potentialities of the numerical tool in the treatment and presentation of results. During the experimental campaign two test cells with distinct inner layers: (i) one with a reference mortar, hereinafter referred to as REFM test cell (Without PCM); (ii) another with a PCM mortar, hereinafter referred to as the PCMM test cell (With PCM). The test cells were placed outdoors and therefore have a differential effect of solar radiation. The temperatures monitored inside the REFM and PCMM test cells during the experimental campaign were compared with the values resulting from the numerical simulation using the finite element method with 3D discretization, and the obtained results revealed a significant coherence of values. An application of a solar radiation method was developed and linked, without neglecting the observation of the effect of the PCM.

This work presents an extensive numerical simulation to analyse the influence of the coating layers on the performance of construction systems, in order to make the constructions projects feasible, not only economically, but also technically. Through computer simulations based on a defined reference model for the study, the present work study the influence of different layers of floor, roof and internal and external wall systems, on the thermal performance. Finally, analysing the results, for the reference model used, identified the materials and elements with the greatest influence on a thermal - all elements of tension, roofing system and facades, especially an absence of external cladding and the use of thermal blankets on the roof.

This chapter is devoted to study the melting process of a phase change material into a triplex tube heat exchanger with finned copper tubes. The focus is on the heat transfer between a heating fluid (water) and phase change material to power a liquid-desiccant air conditioning system. Here, different topics related to fundamentals and applications of the phase change materials, and storage energy system with especial reference to a triplex tube heat exchanger are presented and discussed. Results of the temperature fields, liquid fraction, and velocity, as well as the energy history of the involved phases in the heating and melting processes are presented, compared with experimental data, and analyzed.

The influence of the coating layers on the performance of construction systems is an essential parameter to assess the use of materials and elements of the systems, in order to make the project feasible, not only economically, but also technically. Through numerical simulations based on a defined reference model for the study, the present work study the influence of different layers of floor, roof and, internal and external wall systems, on the natural lighting performance. Finally, analysing the results, for the reference model used, identified the materials and elements with the greatest influence on lighting performance—the internal finishes of the environment and the type of glass used in the external walls.

Petroleum has been extracted from oil reservoirs using different techniques. This activity is accompanied for a large amount of water and sometimes mixed with gas. This produced water has a high oil concentration and other toxic chemical compounds, thus, it must be treated to be reused or released to environment according to environmental protection regulations. Currently, ceramic membrane technology has been employed in the wastewater treatment, due to its high benefit&ndash, cost ratio. In this sense, this work aims to study the oil&ndash, water mixture separation process using a new configuration of tubular ceramic membrane module by computational fluid dynamic (ANSYS Fluent software). The proposed model is composed of mass and linear momentum conservation equations coupled to Darcy&rsquo, s law and SST k-&omega, turbulence model. Results of the volumetric fraction, pressure, and velocity distribution of the oil and water phases are presented and discussed. The results indicated that the proposed model and new device both have great potential to be used on the water/oil separation process and that the transmembrane pressure remains constant in the axial direction and decreases radially through the membranes, indicating an efficient system that favors the transport of clean water and oil retention.

This work presents an extensive numerical simulation to analyze the influence of the coating layers on the performance of construction systems, in order to make the constructions projects feasible, not only economically but also technically. Through numerical simulations based on a defined reference model, the present work studied the influence of different layers of floor, roof and internal and external wall systems, on the acoustic, thermal, and luminous performance of buildings in Brazil. The results showed the materials and elements with the greatest influence on: lighting performance are the internal finishes of the environment and the type of glass used in the external windows. On thermal performance, all elements of the roofing system and fa&ccedil, ades, especially an absence of external cladding and the use of thermal blankets on the roof, have greater influence. The acoustic performance of the fa&ccedil, ade function on the external windows and acoustic performance of the floor system are mainly influenced by the thickness of the structural element and the use of a ceiling and acoustic blanket, acoustic performance of internal walls is affected by typology of the structured element of the wall and thickness.

Nearly 95% of the Brazilian production of natural gypsum comes from the state of Pernambuco, from the Araripe Gypsum Center. Of the 95%, that is to say, of the 1.3 million ton/year production, 61% is allotted to the making of blocks and plates, 35% for coverings, 3% for ceramic moulding, and 1% for other uses. The Gypsum Center generates nearly 12,000 jobs directly and approximately 60,000 jobs indirectly, and has an annual invoicing of US$300M per annum. In civil construction, the use of gypsum increases continually, because plaster paste is seen by builders as a low cost, quality alternative material to be applied as coatings to internal walls. The reduced cost results in higher productivity on the part of the craftsperson due to the speed of application as well as providing a good final finish. Paint can be applied without needing to apply putty. Bases commonly used for these types of finishes are ceramic and concrete substrates. These materials are known for their excellent mechanical strength and low thermal conductivity. The superior surface quality on both sides of these materials makes them suitable for any thickness of plaster paste. This study evaluates experimentally the adhesion strength of coatings made with gypsum paste, considering different substrates and application heights. There are four types of blocks (ceramic and concrete, non-structural and structural blocks), two types of slice cutting (superficial and penetrating to the substrate) and three application heights (up to 0.6 m, between 0.6 and 1.2 m and above 1.2 m). The results indicated the strong influence by the base and depth of cut on the adhesion, but there was no influence on adherence attributed to the height of application.