cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.20026817.v1
title: Thermal performance and solar absorptance of asbestos-free fiber cement roof tiles under different natural aging processes

description: Abstract Fiber cement roof tiles undergo natural aging processes that may change their surface solar absorptance and thermal performance: carbonation, efflorescence and fungal development. With the aim of identifying the impact of these processes on their absorptance and thermal performance, this research study was undertaken in three stages: a) determination of the aging processes in tiles naturally aged for 28 days and after 36 months of exposure; b) surface temperature measurements by infrared thermography; and c) spectral reflectance measurements with a spectrophotometer to calculate the solar absorptance of the tiles. The results indicate that the carbonation process after 36 months of natural aging reduced the tiles' absorptance and surface temperatures when compared to the new 28 days' tiles. However, tiles with fungal growth after 36 months of exposure showed increased initial absorptance and surface temperatures, indicating that fungal growth can increase building solar heat gains. The results indicated that the natural aging processes of fiber cement tiles considerably affect its thermal performance over the building's lifetime.
DOI: 10.6084/m9.figshare.20026816
title: Thermal characteristics of phase change materials suitable for Brazilian buildings

description: Abstract Phase Change Materials (PCMs) have significantly higher thermal capacity than traditional materials. PCMs increase the thermal inertia of buildings and improve their thermal performance depending on the climate conditions. PCMs are generally used in buildings exposed to the Northern Hemisphere's climate conditions; however, there is very little information about the effect of these materials in buildings located in tropical areas. This paper presents the essential thermal characteristics that these materials require (latent heat and melting point) to be able to contribute to improve the thermal performance of Brazilian buildings. Simulations of the thermal response of buildings with and without PCMs were carried out. The first stage aimed to reproduce the thermal behaviour of a real prototype - with PCMs available in the market in order to validate the simulations. The second stage included parametric simulations of the thermal response of a prototype with hypothetical PCMs. The characteristics of these hypothetical materials were obtained from variations of the original ones. The results show the values of the latent heat and melting point most appropriate to Brazilian buildings.
DOI: 10.6084/m9.figshare.20026816.v1
title: Thermal characteristics of phase change materials suitable for Brazilian buildings

description: Abstract Phase Change Materials (PCMs) have significantly higher thermal capacity than traditional materials. PCMs increase the thermal inertia of buildings and improve their thermal performance depending on the climate conditions. PCMs are generally used in buildings exposed to the Northern Hemisphere's climate conditions; however, there is very little information about the effect of these materials in buildings located in tropical areas. This paper presents the essential thermal characteristics that these materials require (latent heat and melting point) to be able to contribute to improve the thermal performance of Brazilian buildings. Simulations of the thermal response of buildings with and without PCMs were carried out. The first stage aimed to reproduce the thermal behaviour of a real prototype - with PCMs available in the market in order to validate the simulations. The second stage included parametric simulations of the thermal response of a prototype with hypothetical PCMs. The characteristics of these hypothetical materials were obtained from variations of the original ones. The results show the values of the latent heat and melting point most appropriate to Brazilian buildings.
DOI: 10.6084/m9.figshare.20026820
title: Discussion of the limits of the thermal properties of building envelopes according to Brazilian thermal performance standards

description: Abstract One of the purposes of thermal performance standards for buildings is to evaluate the building envelope, identifying those building that are appropriate and can guarantee a minimum performance and hence the thermal comfort of users. In Brazil, there are currently two standards that regulate the thermal performance of residential buildings: NBR 15220 (2005) and NBR 15575 (2013). Some studies point out inconsistencies in these standards, especially with regard to the limit values for the thermo-physical characteristics of walls and roofs. The aim of this paper is to evaluate the thermal comfort of a multifamily residential building, adopting Mahoney's limit values, comparing these results with those obtained through the normative values for each of Brazil's bioclimatic zones. The analysis was performed through simulations using EnergyPlus© during one year in 24 Brazilian cities. The results point to the need to review especially the values adopted for the thermal capacity of walls and the thermal transmittance and solar absorptance of envelopes in NBR 15220 (2005), as well as the need to establish values for the thermal capacity of walls and the thermal capacity and solar absorptance of envelopes in the case of NBR 15575.
DOI: 10.6084/m9.figshare.20026820.v1
title: Discussion of the limits of the thermal properties of building envelopes according to Brazilian thermal performance standards

description: Abstract One of the purposes of thermal performance standards for buildings is to evaluate the building envelope, identifying those building that are appropriate and can guarantee a minimum performance and hence the thermal comfort of users. In Brazil, there are currently two standards that regulate the thermal performance of residential buildings: NBR 15220 (2005) and NBR 15575 (2013). Some studies point out inconsistencies in these standards, especially with regard to the limit values for the thermo-physical characteristics of walls and roofs. The aim of this paper is to evaluate the thermal comfort of a multifamily residential building, adopting Mahoney's limit values, comparing these results with those obtained through the normative values for each of Brazil's bioclimatic zones. The analysis was performed through simulations using EnergyPlus© during one year in 24 Brazilian cities. The results point to the need to review especially the values adopted for the thermal capacity of walls and the thermal transmittance and solar absorptance of envelopes in NBR 15220 (2005), as well as the need to establish values for the thermal capacity of walls and the thermal capacity and solar absorptance of envelopes in the case of NBR 15575.
DOI: 10.6084/m9.figshare.20026661.v1
title: A study on causes of construction delays in real estate projects in the metropolitan region of São Paulo

description: The aim of this article is to list the main causes of delays in Brazilian real estate projects. Based on a literature review, this article starts by identifying the factors that affect construction times around the world, focusing on developing countries. The conditions and difficulties that entrepreneurs and builders face in those countries are probably the same as those in Brazil. Based on this list of delays, a classification and correlation was established, identifying possible causes. This framework was used to perform analytical research in 32 construction works executed in the metropolitan region of São Paulo in the past 7 years. The results showed that although entrepreneurs' interference significantly affects the projects (at least in this sample), the main problems seem to be related much more to internal and organizational issues on the construction site, which are the responsibility of construction managers, than to issues external to the construction environment (rain, soil, market changes, suppliers, customer engagement, etc.). This aspect reinforces the importance of investing in training, planning and control systems and methodologies, even if simplified.
DOI: 10.6084/m9.figshare.20026660.v1
title: Comparative study of managerial practices and EVM management theory: the case of construction

description: Indicators are a major management tool that organizations use to monitor project performance. The EVM indicator has widely been used for about 40 years. Nevertheless, only few studies have been conducted about its use in the construction industry. In addition, some authors claim that the theoretical foundation of EVM has been incorrectly used in the construction industry. The main objective of this article is to present a comparative study of the theoretical foundations and the practical use of the EVM indicator. This is an exploratory study involving a case study in 5 construction projects. After the field research, the practices used were identified and compared with the EVM theory. The researchers observed that there were critical success factors such as: staff training, maturity in project management, support from high management, and the need of pre-defined procedures. They also observed that the EVM offered benefits such as better cost control, scope and communication about the project's performance. Additionally, they concluded that the method applied enabled the successful achievement of the goals and the validation of the research hypothesis.
DOI: 10.6084/m9.figshare.20026658.v1
title: Evaluation of water consumption on taps at a university campus

description: Currently, water consumption is on the agenda of most organizations around the world. As well as the environmental benefits brought about by a more efficient use of natural resources; there are also economic reasons to reduce operational costs. This paper presents the results of measurements made on water taps at the Pontifical Catholic University of Campinas, Brazil. The measurements were obtained automatically through a wireless sensor network, using Rfbee and Xbee devices specifically designed to collect the data. The main results show that water consumption is high and that measures must be taken to reduce consumption to less than 5 litres per minute.
DOI: 10.6084/m9.figshare.20026649.v1
title: The salt efflorescence in the Church of Santo Alexandre, Belém - PA

description: The structural masonry of the historical monuments of the city of Belém, Brazil, is made of stones and solid bricks fixed with lime mortar, which is affected by different pathologies, including salt efflorescence and moisture action. Some authors explain that these two agents cause layer detachment, mortar pulverization, cracks and a whitened appearance. This aim of this study was to identify the degradation process affecting the masonry of the right transept of the Church of Santo Alexandre, using instrumental analytical techniques. Laboratory analyses were used in order to understand the saline efflorescence process, the material damage it causes and the main kinds of salts. The first step in the study was to map out the masonry and the damage, showing the current situation and the most damaged areas. That was followed by a physical characterisation through an analysis of mortar particle sizes and proportions, analysis of masonry moisture contents, chemical characterisation -qualitative and quantitative chemical analysis of soluble salts, and mineralogical characterisation by X-ray diffraction. The techniques applied were effective and contributed to the achievement of a correct diagnosis, guiding the type of interventions required to solve the problem.
DOI: 10.6084/m9.figshare.20026643.v1
title: Geopolymetric binder produced with fly ash and sodium hydroxide

description: Geopolymeric binders are an alternative material to Portland cement that it are obtained by fly ash polycondensation in an alkaline medium, as long as criteria for selection of precursor materials, mixing parameters and curing regime are observed. By employing ground fly ash and a sodium hydroxide solution, the effect on flexural and compressive strength of prismatic specimens was evaluated through changing solution concentration (8 M, 12 M and 16 M), fly ash - alkaline solution ratio by mass (0.50, 0.55, 0.60, 0.65, 0.70), curing regime (in oven or moist chamber) and age (1, 3 or 7 days) according to the aim of each evaluation. The findings of this study were that a second thermal curing may be dismissed and strength values remained stable over time. In addition, the investigation showed a strong effect between mixing parameters, since strength was improved by increasing the molar concentration and reducing the materials mass ratio.
DOI: 10.6084/m9.figshare.20026642.v1
title: High reactivity pozzolan: a critical evaluation of Pozzolanic Activity Index (PAI) with lime using X-Ray Diffraction

description: Mineral pozzolanic admixtures are present in many of cementitious materials used in the production of structural concrete. The selection of the pozzolan requires prior characterization of its reactive potential, which can be obtained directly by using the modified Chapelle test, or indirectly, by performing a compressive strength test of the mortar with Portland cement or hydrated lime. The objective of this study is to quantify the pozzolanic activity index with lime of rice husk ash, silica fume and metakaolin, as well as the use of fillers such as limestone and quartz dust as inert reference material. The X-ray diffraction (XRD) of pastes identical to those used in standard mortars allows us to analyse portlandite consumption, an essential indicative of pozzolanic activity. The combined analysis of IAP with lime and X-ray diffraction (XRD) is aimed at verifying the rate of consumption of calcium hydroxide in the mixtures recommended by standard procedures, creating an opportunity to critically analyse their suitability. The results indicate that the NBR 5751 procedure is not appropriate to compare the reactive potential of super pozzolan, since the investigation showed that the amount of lime in the mixture was completely consumed, preventing a comparative evaluation of the compressive strength results based on standardized testing.
DOI: 10.6084/m9.figshare.20026829
title: Integration of thermal energy simulation in the early design stages: six case studies

description: Abstract The aim of this paper is to demonstrate the feasibility of energy tool integration to the design process from the early stages. With that purpose, it presents a systematization of the procedures that take place between designer and modeler, based on six case studies of buildings in a warm climate. The key elements are the understanding of the buildings' characteristics, programming, including goals and needs, and solution proposals and designer´s intentions. Such concerns led to the development of a checklist to improve the dialogue between modeller and designer. The results also highlight the variables that most influence the building's energy consumption, and the interaction between modeller and designer, according to their profile, the implicit freedom and constraints in the programing, the recurrent solutions which, in some cases, could do without the simulations. Besides the confirmation of the feasibility of early integration, the main contribution of this study is the mapping of the processes between designer and modeller and the intensity of the relationships, demonstrating the potential and constraints of integration, which may be useful in the development of energy tools and training for modellers.
DOI: 10.6084/m9.figshare.20026829.v1
title: Integration of thermal energy simulation in the early design stages: six case studies

description: Abstract The aim of this paper is to demonstrate the feasibility of energy tool integration to the design process from the early stages. With that purpose, it presents a systematization of the procedures that take place between designer and modeler, based on six case studies of buildings in a warm climate. The key elements are the understanding of the buildings' characteristics, programming, including goals and needs, and solution proposals and designer´s intentions. Such concerns led to the development of a checklist to improve the dialogue between modeller and designer. The results also highlight the variables that most influence the building's energy consumption, and the interaction between modeller and designer, according to their profile, the implicit freedom and constraints in the programing, the recurrent solutions which, in some cases, could do without the simulations. Besides the confirmation of the feasibility of early integration, the main contribution of this study is the mapping of the processes between designer and modeller and the intensity of the relationships, demonstrating the potential and constraints of integration, which may be useful in the development of energy tools and training for modellers.
DOI: 10.6084/m9.figshare.20026831
title: CFD as a tool applied in simulation of indoor natural ventilation by wind forces: case study in vertical typologies adopted in the Social Housing Program "My house, My Life"

description: Abstract Natural ventilation is a passive architectural design strategy that should be used whenever possible in hot climate countries like Brazil. One of the several methods used to predict the behaviour of natural ventilation is computational fluid dynamics or CFD. The purpose of this paper is to analyse natural ventilation by wind action inside buildings by using the CFD simulation method. Three multifamily buildings from the Brazilian housing program Minha Casa, Minha Vida were taken as case studies. The performance of ventilation for three wind incidence angles (0º, 90º and 135º) is analysed. The study presents both quantitative results (average wind speed in each internal environment) and qualitative results (images of the external and internal air flow). The results indicate best ventilation performance in type 1, "H" type design, wherein the large opening in the indentation played a decisive role. In the type 2 design, a near square typology, the design solution to ventilate the bathroom and kitchen through the opening of the service area proved to be inefficient. The worst performance was seen in type 3, a building with large monolithic facades (no indentations).
DOI: 10.6084/m9.figshare.20026831.v1
title: CFD as a tool applied in simulation of indoor natural ventilation by wind forces: case study in vertical typologies adopted in the Social Housing Program "My house, My Life"

description: Abstract Natural ventilation is a passive architectural design strategy that should be used whenever possible in hot climate countries like Brazil. One of the several methods used to predict the behaviour of natural ventilation is computational fluid dynamics or CFD. The purpose of this paper is to analyse natural ventilation by wind action inside buildings by using the CFD simulation method. Three multifamily buildings from the Brazilian housing program Minha Casa, Minha Vida were taken as case studies. The performance of ventilation for three wind incidence angles (0º, 90º and 135º) is analysed. The study presents both quantitative results (average wind speed in each internal environment) and qualitative results (images of the external and internal air flow). The results indicate best ventilation performance in type 1, "H" type design, wherein the large opening in the indentation played a decisive role. In the type 2 design, a near square typology, the design solution to ventilate the bathroom and kitchen through the opening of the service area proved to be inefficient. The worst performance was seen in type 3, a building with large monolithic facades (no indentations).
DOI: 10.6084/m9.figshare.20026832
title: Multi-objective optimization of the dimensions of a dwelling building based in energy and structure simulation

description: Abstract The development of computer technology in the past few decades led optimization associated with parameterization to develop designs that perform better, with or without the use of computer simulation. The purpose of this study was to apply this method to optimize the shape of a single family residential building with the goal of finding the design that presented the best thermal performance with the lowest cost of construction materials, considering structural constraints. The software Rhinoceros, Energy Plus and plug-ins for parametric modelling, information exchange between software and conduction of optimization were used in this study. Two simulations were performed, one considering the cost of construction materials and combined heating and cooling degree-hours, the second considering cost and heating degree-hour, which produced more relevant results. Two cases of each Pareto Front were selected for analysis, out of 19.8 thousand and 27.4 thousand cases obtained through evolutionary algorithms. Despite the limitations presented by some tools, the study demonstrated that there is great potential for implementation of this technology in the development of architectural projects.
DOI: 10.6084/m9.figshare.20026832.v1
title: Multi-objective optimization of the dimensions of a dwelling building based in energy and structure simulation

description: Abstract The development of computer technology in the past few decades led optimization associated with parameterization to develop designs that perform better, with or without the use of computer simulation. The purpose of this study was to apply this method to optimize the shape of a single family residential building with the goal of finding the design that presented the best thermal performance with the lowest cost of construction materials, considering structural constraints. The software Rhinoceros, Energy Plus and plug-ins for parametric modelling, information exchange between software and conduction of optimization were used in this study. Two simulations were performed, one considering the cost of construction materials and combined heating and cooling degree-hours, the second considering cost and heating degree-hour, which produced more relevant results. Two cases of each Pareto Front were selected for analysis, out of 19.8 thousand and 27.4 thousand cases obtained through evolutionary algorithms. Despite the limitations presented by some tools, the study demonstrated that there is great potential for implementation of this technology in the development of architectural projects.
DOI: 10.6084/m9.figshare.20026837
title: Analysis of physical uncertainties in computer simulations of residential buildings

description: Abstract The aim of this paper is to analyse physical uncertainties in a computer simulation of a residential building and the implications for its thermal performance. The simulation experiment was performed using the Monte Carlo method, involving the thermal and physical properties of materials. The sensitivity of the variables was also analysed using regression and correlation coefficients. The degree-hours of discomfort criterion for heating and cooling for the climate of Florianópolis-SC were considered, according to adaptive thermal comfort limits. The results showed that uncertainties in degree-hours are high, i.e., 32% for cooling discomfort and 53% for heating discomfort. The uncertainty is largely due to the average monthly temperature of the ground. Other variables, such as the solar absorptance of the roof and the specific heat of the mortar of the walls had a relevant impact on heat discomfort. The density of the mortar and the specific heat of the brickwork walls affected the cooling discomfort. These variables need proper accuracy, either through more reliable databases and/or through field or laboratory measurements.