Papers by White dos Santos
Applied Mechanics and Materials, 2017
Compositions with different pipe segments for constructing structural columns were investigated. ... more Compositions with different pipe segments for constructing structural columns were investigated. In this article there is shown a column type composed of five parallel bamboo bars, connected by screws 16 mm and 13 mm in diameter. Compression tests instrumented with displacement transducers are associated with numerical modeling analysis to describe the column load capacity, from the general criteria of dimensioning. The chosen Bamboos are from the species Phyllostachys pubescens due to its favorable characteristics to produce structures and their common use in China, Brazil and other countries of temperate zones. In this proposal, the load capacity is considerably increased and lateral displacements are insignificant compared to the bamboo tested separately. More usual columns 3 and 4 meters long were modeled and presented the load limits of use for these types of structures. Other dimensions of columns can be calculated by the same system, presenting great design opportunities in the construction of the architecture and built spaces. This article shows a great advantage in using columns with bamboo bars compared to other materials used in the architecture, with guarantee and good indexes of security.
The aim of this study was to propose and analyse an experimental mix design method for coating mo... more The aim of this study was to propose and analyse an experimental mix design method for coating mortars using artificial crushing sand as fine aggregate. We sought to identify and standardize the mix design procedures so as to fulfil the working conditions for an external mortar coating under the specifications of ABNT NBR 13281:2005 (ABNT, 2005a). The proposed mix design method was assessed using the following tests: entrained air content, compressive strength, flexural strength tests and adherence, modulus of elasticity, water absorption, porosity, cracking, stereoscopic magnifier images and statistical analysis. We used Portland cement type II with blast furnace slag, hydrated lime type I, and artificial crushing sand gneiss. The conclusion of the study is that the proposed method is efficient and produces good quality coating mortars using artificial crushing sand, according to pre-established conditions. It is an easy and flexible way to obtain the appropriate levels of each com...
Coating mortars and plastering masonry using artificial sand from crushing has become a viable al... more Coating mortars and plastering masonry using artificial sand from crushing has become a viable alternative in recent years, however, there is widespread disagreement with regards to the adequate dosage of materials. The objective of this project was to study coating mortars and plastering masonry with artificial crushing sand and natural sand, in order to evaluate the effects of these aggregates on fresh and hardened states properties under analysis of a more efficient mix design process. The samples were tested for incorporated air content, resistance to compression, traction in flexion and grip, modulus of elasticity; water absorption; porosity. Cracking and statistical tests were performed in three age groups (14, 28 and 85 days). CPII-E-32, CH-I lime, artificial crushing gneiss sand and natural quartz sand were used. The results showed that the artificial aggregate is suitable for use in mixed mortars. The study demonstrated that the type of mortar significantly influences the p...
Journal of Management and Sustainability
This study discusses and analyzes an alternative of IOT reuse as addition in structural mortars, ... more This study discusses and analyzes an alternative of IOT reuse as addition in structural mortars, evaluating the influence of IOT addition contents. The material was physically and chemically characterized. Structural mortars were molded with 10%, 20%, 30% and 40% of addition of IOT in relation to cement mass. We investigate physical properties, mechanical indicators, durability indicators and microstructure. The tailings are composed of predominantly quartz, hematite and goethite, and no components were found that could compromise the cementitious composites. The addition of IOT provided a tendency to reduce open porosity. The addition of 30% IOT was the most efficient in closing pores. All addition contents led to the maintenance or gains in mechanical properties, and a 10% gain in flexural tensile strength was observed for the addition of 10% IOT. The addition of 40% IOT promoted a 14% gain in compressive strength and maintenance of flexural tensile strength. This addition content...
Journal of Management and Sustainability
Nowadays, different organizations and institutions have advanced methodologies and strategies tha... more Nowadays, different organizations and institutions have advanced methodologies and strategies that make it possible to assess, through parameters and indicators, the sustainability of construction projects that materialize the concept of “sustainable building”. The main aim of this research is to carry out a critical analysis between the Sustainable Development Indicators (SDI), released by the IBGE/Brazil, and the most used assessment tools in Brazil, namely: LEED and AQUA. Thus, with regard to the “green buildings” certified by these tools in the Brazilian territory, data collection was carried out in those organizations considering the parameters: the level of certification and the region of Brazil. The lack of synchronization between the data from the SDI and the assessment tools was found. Finally, recommendations are presented that aim to reduce the inconsistencies found in the assessment tools.
Construction and Building Materials
Abstract This paper assessed the variables affecting the shrinkage and cracking of blended metaka... more Abstract This paper assessed the variables affecting the shrinkage and cracking of blended metakaolin/blast furnace slag (MK/BFS) alkali-activated mortars (AAM) designed for concrete repair. Twenty-one initial MK/BFS formulations with fixed workability were subjected to compressive strength and static modulus of elasticity, after which five formulations were selected for further tests. They were evaluated as to free shrinkage and restrained shrinkage on a concrete substrate and restrained shrinkage with stress concentrating devices. Mortars were also analysed in a concrete substrate with 0.25% addition of polypropylene fibres. The formulation with the lowest crack density was further studied in other conditions (prevention of water evaporation, thermal curing, higher aggregate/binder ratio, the addition of 0.25 and 0.75% PP fibres). In general, the results show that MK/BFS AAM may present satisfactory mechanical performance (high compressive strength, modulus of elasticity and bond strength) and free shrinkage results. However, this may bring misleading conclusions. Severe cracking is observed when the movement is restricted, irrespective of the formulation. Lower BFS content (20%), higher aggregate/binder ratio, fibres and prevention of moist evaporation help the reduction but not suppress the cracks, which were observed in AAM and also in reference PC mortar.
Tópicos em Administração - Volume 32
Força, Crescimento e Qualidade da Engenharia Civil no Brasil 3
Direitos para esta edição cedidos à Atena Editora pelos autores. Todo o conteúdo deste livro está... more Direitos para esta edição cedidos à Atena Editora pelos autores. Todo o conteúdo deste livro está licenciado sob uma Licença de Atribuição Creative Commons. Atribuição-Não-Comercial-NãoDerivativos 4.0 Internacional (CC BY-NC-ND 4.0). O conteúdo dos artigos e seus dados em sua forma, correção e confiabilidade são de responsabilidade exclusiva dos autores, inclusive não representam necessariamente a posição oficial da Atena Editora. Permitido o download da obra e o compartilhamento desde que sejam atribuídos créditos aos autores, mas sem a possibilidade de alterá-la de nenhuma forma ou utilizá-la para fins comerciais. Todos os manuscritos foram previamente submetidos à avaliação cega pelos pares, membros do Conselho Editorial desta Editora, tendo sido aprovados para a publicação com base em critérios de neutralidade e imparcialidade acadêmica. A Atena Editora é comprometida em garantir a integridade editorial em todas as etapas do processo de publicação, evitando plágio, dados ou resultados fraudulentos e impedindo que interesses financeiros comprometam os padrões éticos da publicação. Situações suspeitas de má conduta científica serão investigadas sob o mais alto padrão de rigor acadêmico e ético.
Revista IBRACON de Estruturas e Materiais
abstract: Water retaining agents are the main admixtures used to retain water against evaporation... more abstract: Water retaining agents are the main admixtures used to retain water against evaporation and substrate suction, and there are several chemical compounds for this purpose. To deepen the knowledge of mortar admixtures, several concentrations (0%, 1.5%, 5%, 10% and 15%) of three different types of admixtures were studied: an acrylic polymer, a cellulosic and ethylene vinyl acetate. Fresh properties (consistency, water retention, density and incorporated air), physical indexes (density and porosity) and compressive strength at 28 days were analyzed. It has been found that admixtures can act in different ways on mortars depending on the type of chemical agent used and can significantly affect the mechanical and durability characteristics in the fresh and hardened state. With this work it was verified the importance of searching references about the influence of chemical compounds before using it.
O sistema de Fachadas Ventiladas e uma solucao relativamente recente, que foi desenvolvida na Eur... more O sistema de Fachadas Ventiladas e uma solucao relativamente recente, que foi desenvolvida na Europa a partir da necessidade de reducao de custos com energia para refrigeracao e calefacao das edificacoes. Esse sistema e considerado uma inovacao construtiva tanto pela questao estetica, como funcional. E composto basicamente por um suporte de fixacao, por uma câmara de ar em movimento, pelos elementos de fixacao, pelo material de revestimento e pelas juntas abertas. A câmara de ar ventilada e as juntas abertas sao responsaveis pelo bom desempenho termoacustico do sistema e pela estanqueidade a agua quando corretamente dimensionadas. Atraves de uma revisao bibliografica, buscouse nesse trabalho estudar o SFV, apresentando as diversas solucoes, os materiais para revestimento, tipos de fixacao e juntas. Apos a revisao a bibliografica, foram feitas analises das vantagens e desvantagens do sistema. Este se apresentou bastante vantajoso, devido sua eficiencia, facilidade de manutencao, aspe...
TECNOLOGIAS APLICADAS A ENGENHARIA CIVIL
Granitine-based coatings are widely used as a lowcost coatings alternative and high durability. A... more Granitine-based coatings are widely used as a lowcost coatings alternative and high durability. Aiming to use a sustainable material, which presents, in its composition, a type of inert waste from the mining industry, this article presents the outcomes from the implications of replacing part of the binder of the granitine pattern for limestone powder. Considering that previous similar studies were not identified, this research is pioneer and intends to conduct a series of tests to achieve its purpose. Trials for the characterization of ornamental rocks were used, for they are high quality coatings and with excellent durability, when its technological usage characteristics are observed, since currently there are no specific standards for granitine coatings. The features used by manufacturers for this type of coating (reference) were tested, and there were made others replacing the binder by limestone powder. Density tests, apparent porosity, water absorption, uniaxial compression str...
The Open Construction and Building Technology Journal, 2020
Characterization procedures were performed for the aggregates (visual quantification and physical... more Characterization procedures were performed for the aggregates (visual quantification and physical properties of the constituents), and for the concretes (compressive strength, splitting tensile strength test, modulus of elasticity, water absorption, porosity, electrical resistivity, carbonation depth, and digital microscopy). The replacement rate of natural aggregate for CDWA was of 20% in three different particle sizes: sand, gravel 0, and gravel 1.
In recent years the construction industry in Brazil is improving due to the highcompetitiveness i... more In recent years the construction industry in Brazil is improving due to the highcompetitiveness in the market. The projects seek ways to increase productivity in performingservices, streamline and automate processes, and reduce waste. Such factors are used as ameans of reducing costs and complete the work according to planned deadlines. Systemsprecast concrete gained ground in the international scenario and then nationally on thiscontext. Presents itself as a way of building more economical, durable, structurally andarchitecturally versatile, and engage in sustainability issues, as it provides less wastedmaterials. This paper presents the system of precast concrete, pointing from a literature reviewtheir construction methods, their advantages and limitations. We conducted a case studyfocusing on analysis of the planning and execution of works that follow this system. Finally, itwas a proposal of conduct to be followed by professionals and companies, in order to define aproper postur...
Para diminuir ou ate mesmo eliminar os problemas patologicos deve-se obter um rigido controle de ... more Para diminuir ou ate mesmo eliminar os problemas patologicos deve-se obter um rigido controle de qualidade nas etapas de planejamento, projeto, materiais, execucao e uso, de modo a se obter um resultado final satisfatorio. Na cidade de Vicosa, os edificios residenciais de multiplos pavimentos apresentam diversos tipos de patologias, sejam em virtude de erros nas fases de concepcao ou de materializacao da edificacao. Dentro deste contexto, o objetivo principal deste artigo, consistiu em identificar a existencia de patologias nas edificacoes residenciais multifamiliares da cidade de Vicosa e propor diretrizes para um programa de qualificacao do processo de construcao, de modo a orientar acoes no sentido de evitar ou minimizar a incidencia de processos patologicos em futuras edificacoes, garantindo-lhes aspectos vantajosos competitivamente e economicamente, seguranca e atendimento as necessidades e expectativas dos usuarios. Constatou-se que as diretrizes propostas podem ajudar na melh...
Sustainable development in the 21st century depends on the reuse of materials and products, as we... more Sustainable development in the 21st century depends on the reuse of materials and products, as well as on economic and environmental incentives for recycling. Several studies have sought to improve the quality of concrete, as well as its durability and strength, by adding fibers (metallic, polypropylene, carbon, vegetables) or by replacing the aggregate. The use of optical fiber waste in concrete is still incipient and few studies address the use of marble aggregate to be used in concrete. This research assesses the behavior of the mixture composed of: Portland cement + fine aggregate (sand from crushed marble waste) + coarse aggregate (gneiss) + optical fiber waste and water. The compressive strength, the tensile strength and the modulus of elasticity of concrete and the durability of optical fiber waste in alkaline composite were tested through microstructural evaluation. The results present an increase of about 20% in the mechanical properties and a reduction in the rigidity of t...
O desenvolvimento urbano associado ao da industria da construcao civil tem gerado uma grande quan... more O desenvolvimento urbano associado ao da industria da construcao civil tem gerado uma grande quantidade de residuos de construcao e demolicao, atrelada ao crescimento populacional, ao continuo aumento das construcoes de edificacoes e infraestruturas. Diante disto, faz-se necessario um adequado gerenciamento de residuos da construcao civil (RCC) no canteiro de obras, buscando-se: diminuicao de custos, reutilizacao e reciclagem, melhora na imagem da empresa e, melhoria da produtividade e qualidade do produto. Este artigo objetivou avaliar o gerenciamento de residuos de construcao nas obras de responsabilidade da Universidade Federal de Minas Gerais (UFMG) a fim de levantar quais tecnicas de gerenciamento estao presentes e sua eficiencia, bem como adequacao dos canteiros aos requisitos legais no que tange ao gerenciamento de RCC. Para isso, foram aplicados questionarios com perguntas qualitativas e quantitativas e realizou-se visitas tecnicas nas obras da UFMG, buscando verificar e cla...
Essa pesquisa analisa as principais necessidades de alteracoes do processo construtivo, em alvena... more Essa pesquisa analisa as principais necessidades de alteracoes do processo construtivo, em alvenaria estrutural, antes e depois da vigencia da NBR 15575, (2013). Desenvolveu-se um estudo de caso em uma obra destinada a Moradia Universitaria, em Minas Gerais. A obra teve inicio antes da vigencia dessa norma, logo seu atendimento nao se aplicaria, contudo, sua execucao foi realizada conforme as exigencias das demais normas brasileiras aplicadas a construcao civil. Atraves da analise dos dados coletados na visita tecnica realizada, nas entrevistas realizadas com a responsavel tecnica e na verificacao dos documentos disponibilizados pela empresa, foi averiguado que houve o atendimento a grande parte dos requisitos normativos. A partir das informacoes e constatacoes identificadas, formularam-se proposicoes de procedimentos necessarios a validacao do nivel desempenho atendido pela edificacao. O presente estudo de caso demonstrou que, ainda sem a obrigatoriedade do atendimento a norma de d...
The mortar coatings are made in several ways: single layer, two layers, with or without roughcast... more The mortar coatings are made in several ways: single layer, two layers, with or without roughcast, with industrialized mortar or dosed on site. The coatings dosed on site may contain cement, lime, natural or artificial aggregate and / or additives. The qualities of these coatings link to the quality of the construction. However, coatings, sometimes, are not made in the proper manner, use appropriate materials, or are applied under favorable climatic conditions. Disrespecting any of these conditions, there will be pathologies in the coating. Aiming at these problems, we carried out a research to test the adhesion strength of various types of mortar coatings and to analyze possible pathologies, which may arise when the mortars do not suffer the cure process and the substrate is not previously moistened. Expecting to find the coating that has the best result and to associate the possible causes. The conclusion of this study was that the preparation of the substrate, the technique of ap...
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Papers by White dos Santos