cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.20027367.v1
title: Influence of densification of silica fume on the properties of cementitious materials

description: Abstract The silica fume is commercially available in densified form (DS) when subjected to particle agglomeration processing to reduce its volume during transport, or undensified (US) when that process does not occur. The purpose of this study is to evaluate whether the densification of silica fume can influence the properties of cementitious materials. With that purpose, the effect of replacing 10% of Portland cement CP V-ARI by US and DS was investigated. Compressive strength tests were performed on the microconcrete at 1, 3, 7, 14 and 28 days. To explain the mechanical behaviour of the microconcrete, X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersion spectroscopy (EDS) tests were performed on the cement pastes. Due the smaller particle size and the higher specific surface of the US compared to the DS, there was a change in the microstructure of the cement pastes. The US provided a higher consumption of calcium hydroxide (CH) and a lower calcium/silica (Ca/Si) ratio in the cementitious matrix, resulting in a higher compressive strength in the microconcrete with US compared to that with DS. The study concludes that US is more effective when used in the production of cementitious materials.
DOI: 10.6084/m9.figshare.20027369
title: Acoustic performance of t-beam and hollow-block slabs: airborne and impactnoise insulation

description: Abstract Considering the widespread use of T-beam/hollow-block slabs in Brazil, this study examines the behaviour of that system under the effect of airborne and impact noises, in different compositions. Tests were carried out at a specific test facility, according to ISO 10140-5: 2010. The variations used in the systems were: subfloor, resilient layer, wood laminate and porcelain tile floorings, mortar plaster and suspended ceilings. The results showed that the acoustic performance of the T-beam/hollow-block slab is affected by the effect of resonance in the blocks’ cavities and that the addition of a subfloor can compensate the acoustic fragility when compared with the concrete slab, because of the consequent increase in the system’s mass. The results also show that, for the airborne sound insulation, there are no significant differences between the porcelain tiles and the wood laminate flooring, and that the installation of the suspended ceiling made up for the small sound transmission loss of the T-beam/hollow-block slab in relation to the concrete slab.
DOI: 10.6084/m9.figshare.20027369.v1
title: Acoustic performance of t-beam and hollow-block slabs: airborne and impactnoise insulation

description: Abstract Considering the widespread use of T-beam/hollow-block slabs in Brazil, this study examines the behaviour of that system under the effect of airborne and impact noises, in different compositions. Tests were carried out at a specific test facility, according to ISO 10140-5: 2010. The variations used in the systems were: subfloor, resilient layer, wood laminate and porcelain tile floorings, mortar plaster and suspended ceilings. The results showed that the acoustic performance of the T-beam/hollow-block slab is affected by the effect of resonance in the blocks’ cavities and that the addition of a subfloor can compensate the acoustic fragility when compared with the concrete slab, because of the consequent increase in the system’s mass. The results also show that, for the airborne sound insulation, there are no significant differences between the porcelain tiles and the wood laminate flooring, and that the installation of the suspended ceiling made up for the small sound transmission loss of the T-beam/hollow-block slab in relation to the concrete slab.
DOI: 10.6084/m9.figshare.20027370
title: Performance evaluation of an alternative composite for urban systems and low-cost housing

description: Abstract This paper presents a cement composite, industrial sludge waste and PET flakes composite, aiming at its potentialization for possible use in urban systems and low-cost housing. It is justified by the socio-environmental problems related to the consumption of natural raw materials and by the inappropriate disposal of products and waste in the environment. Hence, the proportions 1:3, 1:4 and 1:5 of cement and residues were tested, with sludge volume substitutions by PET at the rates of 10%, 20% and 30%. Physical-mechanical properties such as compressive strength, water absorption and porosity at 28 and 90 days were evaluated in non-degraded samples, in addition to friction wear parameters. The physical-mechanical properties were also measured at 35 and 42 days in samples that underwent accelerated degradation cycles. In general, there was an increase in mechanical strength with curing and a decrease with the insertion of sludge. The material showed low degradation in the wear tests. As for water absorption and porosity, the values increased with the addition of residue and with curing, easily bypassed with the reduction of sludge and the adoption of waterproofing solutions.
DOI: 10.6084/m9.figshare.20027370.v1
title: Performance evaluation of an alternative composite for urban systems and low-cost housing

description: Abstract This paper presents a cement composite, industrial sludge waste and PET flakes composite, aiming at its potentialization for possible use in urban systems and low-cost housing. It is justified by the socio-environmental problems related to the consumption of natural raw materials and by the inappropriate disposal of products and waste in the environment. Hence, the proportions 1:3, 1:4 and 1:5 of cement and residues were tested, with sludge volume substitutions by PET at the rates of 10%, 20% and 30%. Physical-mechanical properties such as compressive strength, water absorption and porosity at 28 and 90 days were evaluated in non-degraded samples, in addition to friction wear parameters. The physical-mechanical properties were also measured at 35 and 42 days in samples that underwent accelerated degradation cycles. In general, there was an increase in mechanical strength with curing and a decrease with the insertion of sludge. The material showed low degradation in the wear tests. As for water absorption and porosity, the values increased with the addition of residue and with curing, easily bypassed with the reduction of sludge and the adoption of waterproofing solutions.
DOI: 10.6084/m9.figshare.20027373
title: Comparative numerical modelling of the Florestinhabridge, built in a timber and concrete composite structure

description: Abstract Composite structures built with sections made of wood and concrete are more durable and economic. The performance of these structures can be analysed with programmes that use the finite element method. The purpose of this study is to compare the vertical displacement obtained by the finite element method, the theoretical results found by the Orthotropic Timber Bridges programme and an experimental analysis of the Florestinhabridge. Three numerical models were performed. For models 1 and 2, timber beams with circular cross sections were applied, and for model 3, beams with a square cross section were used. The results of model 1 are close to the experimental data and present standard deviation for displacement under the central loading of ± 0.69 mm, which is 1.56% of the mean percentage error, and presents ± 0.73 mm for the lateral loading, which is 1.12% of the mean percentage error. The numerical models 1 and 2 satisfactorily represented the experimental models, demonstrating that the application of the finite element method was satisfactory for the analysis of the bridge in question.
DOI: 10.6084/m9.figshare.20027373.v1
title: Comparative numerical modelling of the Florestinhabridge, built in a timber and concrete composite structure

description: Abstract Composite structures built with sections made of wood and concrete are more durable and economic. The performance of these structures can be analysed with programmes that use the finite element method. The purpose of this study is to compare the vertical displacement obtained by the finite element method, the theoretical results found by the Orthotropic Timber Bridges programme and an experimental analysis of the Florestinhabridge. Three numerical models were performed. For models 1 and 2, timber beams with circular cross sections were applied, and for model 3, beams with a square cross section were used. The results of model 1 are close to the experimental data and present standard deviation for displacement under the central loading of ± 0.69 mm, which is 1.56% of the mean percentage error, and presents ± 0.73 mm for the lateral loading, which is 1.12% of the mean percentage error. The numerical models 1 and 2 satisfactorily represented the experimental models, demonstrating that the application of the finite element method was satisfactory for the analysis of the bridge in question.
DOI: 10.6084/m9.figshare.20027379
title: State-of-art review of current standards and specifications concerning recycled aggregates from CDW

description: Abstract Brazil has specific standards that guide the use of recycled aggregates in pavement construction and nonstructural concrete. However, due to the fact that the recycling of construction and demolition waste (CDW) is still a recent activity in the in Brazil, when compared to other countries, it is understandable that there is a gap regarding the standardization of these materials, as well as some resistance by the construction industry to using them. This study conducts a systematic analysis of the literature on technical and normative specifications on the use of recycled aggregates at a national and international level. In this analysis, the technical, regulatory and quality control standards and guidelines for the use of recycled aggregates from 12 countries, including Brazil were examined. A systematic analysis of the standards allowed an appraisal of the international technical and normative production examined, supplemented by a brief comparison with the latest national review on the subject. This enabled the authors to develop a proposal for technical and normative guidelines for the use of recycled construction and demolition materials in Brazil. It is expected that the results of this study will support the sector in the further development of technical specifications and standards, producing practical contributions for the consolidation of the CDW recycling in the country.
DOI: 10.6084/m9.figshare.20027379.v1
title: State-of-art review of current standards and specifications concerning recycled aggregates from CDW

description: Abstract Brazil has specific standards that guide the use of recycled aggregates in pavement construction and nonstructural concrete. However, due to the fact that the recycling of construction and demolition waste (CDW) is still a recent activity in the in Brazil, when compared to other countries, it is understandable that there is a gap regarding the standardization of these materials, as well as some resistance by the construction industry to using them. This study conducts a systematic analysis of the literature on technical and normative specifications on the use of recycled aggregates at a national and international level. In this analysis, the technical, regulatory and quality control standards and guidelines for the use of recycled aggregates from 12 countries, including Brazil were examined. A systematic analysis of the standards allowed an appraisal of the international technical and normative production examined, supplemented by a brief comparison with the latest national review on the subject. This enabled the authors to develop a proposal for technical and normative guidelines for the use of recycled construction and demolition materials in Brazil. It is expected that the results of this study will support the sector in the further development of technical specifications and standards, producing practical contributions for the consolidation of the CDW recycling in the country.
DOI: 10.6084/m9.figshare.20027378
title: Accelerated degradation protocol of the EBR-CFRP strengthening system applied to reinforced concrete beams

description: Abstract In general, all materials used in the construction industry are subject to the influence of degradation mechanisms, which are characterized by a sequence of chemical, physical, and mechanical changes. In the case of reinforced concrete elements strengthened with composite materials, it is generally observed that degradation affects the most sensitive part of the strengthening system, the epoxy adhesives. This study is based on the use of the Accelerated Conditioning Protocol (ACP) presented by ACI 440.9R (AMERICAN…, 2015) for the evaluation of the durability of reinforced concrete beams flexurally strengthened with CFRP sheets applied according to the EBR technique. The results of the ACP were compared with those obtained through natural weathering tests. The results showed that epoxy adhesives had their mechanical properties significantly reduced, while the CFRP composites remained unchanged after exposure to weathering or to accelerated degradation. The strengthening system greatly increased the load carrying capacity and stiffness of the beams. However, the tests carried out after an accelerated degradation cycle lasting 1,000 h (42 days) and those carried out after 6 months’ exposure to weathering showed a reduction of approximately 10% in the load carrying capacity of the strengthened elements, indicating a possible degradation of the strengthening system.
DOI: 10.6084/m9.figshare.20027378.v1
title: Accelerated degradation protocol of the EBR-CFRP strengthening system applied to reinforced concrete beams

description: Abstract In general, all materials used in the construction industry are subject to the influence of degradation mechanisms, which are characterized by a sequence of chemical, physical, and mechanical changes. In the case of reinforced concrete elements strengthened with composite materials, it is generally observed that degradation affects the most sensitive part of the strengthening system, the epoxy adhesives. This study is based on the use of the Accelerated Conditioning Protocol (ACP) presented by ACI 440.9R (AMERICAN…, 2015) for the evaluation of the durability of reinforced concrete beams flexurally strengthened with CFRP sheets applied according to the EBR technique. The results of the ACP were compared with those obtained through natural weathering tests. The results showed that epoxy adhesives had their mechanical properties significantly reduced, while the CFRP composites remained unchanged after exposure to weathering or to accelerated degradation. The strengthening system greatly increased the load carrying capacity and stiffness of the beams. However, the tests carried out after an accelerated degradation cycle lasting 1,000 h (42 days) and those carried out after 6 months’ exposure to weathering showed a reduction of approximately 10% in the load carrying capacity of the strengthened elements, indicating a possible degradation of the strengthening system.
DOI: 10.6084/m9.figshare.19902403
title: Key elements to enable systemic innovation in construction firms

description: Abstract The construction industry is generally known to be resistive to change and reluctant to embrace new technologies. Innovation, which might be described as the successful exploitation of new ideas, is usually seen as the key to unlocking the industry’s potential. Although there is no doubt that some progress has been made, construction innovation still occurs in a random manner, not as a systemic and managed process. Regardless of the growing number of studies on construction innovation management, there is still a lack of research that identify, compile, classify, and summarize the innovation enablers in construction. Thus, based on a Systematic Literature Review (SLR), this paper aims to provide a holistic understanding of the key elements that enable systemic innovation in construction from a firm-level perspective. The review incorporated data from 38 articles to establish a set of 15 enablers of innovation in construction firms, such as innovation culture, external collaboration (open innovation), knowledge management, and upper management support. The enablers were classified into five different aspects of innovation management: strategic, organizational, human, processual, and financial. The review also sought to identifypractices, routines, methods, or tools that can be adopted to increase innovation activity in construction firms.
DOI: 10.6084/m9.figshare.19902403.v1
title: Key elements to enable systemic innovation in construction firms

description: Abstract The construction industry is generally known to be resistive to change and reluctant to embrace new technologies. Innovation, which might be described as the successful exploitation of new ideas, is usually seen as the key to unlocking the industry’s potential. Although there is no doubt that some progress has been made, construction innovation still occurs in a random manner, not as a systemic and managed process. Regardless of the growing number of studies on construction innovation management, there is still a lack of research that identify, compile, classify, and summarize the innovation enablers in construction. Thus, based on a Systematic Literature Review (SLR), this paper aims to provide a holistic understanding of the key elements that enable systemic innovation in construction from a firm-level perspective. The review incorporated data from 38 articles to establish a set of 15 enablers of innovation in construction firms, such as innovation culture, external collaboration (open innovation), knowledge management, and upper management support. The enablers were classified into five different aspects of innovation management: strategic, organizational, human, processual, and financial. The review also sought to identifypractices, routines, methods, or tools that can be adopted to increase innovation activity in construction firms.
DOI: 10.6084/m9.figshare.20027385
title: Electrical resistivity of concrete by chloride migration test: comparison with the four-electrode method

description: Abstract One of the main parameters used for the monitoring of steel corrosion in reinforced concrete structures is electrical resistivity. This study aims to compare the electrical resistivity measured by the four-electrodes method with the resistivity calculated by the chloride migration test, based on Ohm's laws. In this way, it would be possible to validate obtaining this property by chloride migration test results. For this purpose, concrete specimens were cast with the partial replacement of Portland cement, 10% by mass, by the following supplementary cementitious materials: silica, rice husk ash, metakaolin and fly ash. The results showed that the supplementary cementitious materials have an influence on the electrical resistivity values obtained, and samples containing more reactive additions reached electrical resistivities higher than the reference mix sample. A comparison of the techiques indicated that the values did not differ significantly. That implies that the electrical resistivity of concrete can be reliably obtained by performing the chloride ion migration test.
DOI: 10.6084/m9.figshare.20027385.v1
title: Electrical resistivity of concrete by chloride migration test: comparison with the four-electrode method

description: Abstract One of the main parameters used for the monitoring of steel corrosion in reinforced concrete structures is electrical resistivity. This study aims to compare the electrical resistivity measured by the four-electrodes method with the resistivity calculated by the chloride migration test, based on Ohm's laws. In this way, it would be possible to validate obtaining this property by chloride migration test results. For this purpose, concrete specimens were cast with the partial replacement of Portland cement, 10% by mass, by the following supplementary cementitious materials: silica, rice husk ash, metakaolin and fly ash. The results showed that the supplementary cementitious materials have an influence on the electrical resistivity values obtained, and samples containing more reactive additions reached electrical resistivities higher than the reference mix sample. A comparison of the techiques indicated that the values did not differ significantly. That implies that the electrical resistivity of concrete can be reliably obtained by performing the chloride ion migration test.
DOI: 10.6084/m9.figshare.20027388
title: Guidelines for the development of Student Housing buildings

description: Abstract Student housing was discussed in the literature under the aspects of residential preference and satisfaction; inducing factors of behavior and demand in the real estate market; and influencing variables in choosing the habitation. However, the works that approach topics about real estate meant for students and the new products of the Brazilian real estate, the ones named Student Housing (SH), are scarce. Within this context, the objective of this research is to propose guidelines to orient the development process of SH buildings. For this purpose, the work proposed, initially, through a comparative study of seven SH real states, to investigate the main characteristics of this product model. Such information, added to the bibliographic review of the literature, allowed the exploration, through a survey, of university students’ opinion about the importance of four pre-established requirements. The results revealed that many attributes present in new Brazilian SH buildings are not considered important or are indifferent from the students' point of view, which shows additional and unnecessary costs for investors. In contrast, the study identified several requirements valuable to users. Based on thist, twelve guidelines were suggested to orient the student market designers, developers, and investors in the development of their products.
DOI: 10.6084/m9.figshare.20027388.v1
title: Guidelines for the development of Student Housing buildings

description: Abstract Student housing was discussed in the literature under the aspects of residential preference and satisfaction; inducing factors of behavior and demand in the real estate market; and influencing variables in choosing the habitation. However, the works that approach topics about real estate meant for students and the new products of the Brazilian real estate, the ones named Student Housing (SH), are scarce. Within this context, the objective of this research is to propose guidelines to orient the development process of SH buildings. For this purpose, the work proposed, initially, through a comparative study of seven SH real states, to investigate the main characteristics of this product model. Such information, added to the bibliographic review of the literature, allowed the exploration, through a survey, of university students’ opinion about the importance of four pre-established requirements. The results revealed that many attributes present in new Brazilian SH buildings are not considered important or are indifferent from the students' point of view, which shows additional and unnecessary costs for investors. In contrast, the study identified several requirements valuable to users. Based on thist, twelve guidelines were suggested to orient the student market designers, developers, and investors in the development of their products.