A mixed methods study on choice of media influence on construction industry communication

This study focuses on the use of different communication media for solving problems in the construction industry. The focus of this research is on design-problems containing spatial information and are informally reported between site supervision and design professionals. Due to the fragmented nature of the construction industry, miscommunication is a well-known and common problem. Yet, this fragmented nature is necessary in order to build a complex product involving many different types of professionals. To better understand the issue, this study uses previous literature, such as those published on media richness theory, problem-solving strategy, and construction specific communications, in a three-phased sequential mixed-methods approach. The phases included an online survey with industry professionals (phase 1), interviews with industry professionals (phase 2), and a quasi-experiment (phase 3). Quantitative and qualitative data were analyzed depending on the phase. Results indicate that construction industry communication relies strongly on face-to-face interaction, and telephone and email communications. The need for a `paper trail\u27 is an important factor driving communication patterns. Finally, phase 3 suggested that communication media that allow for immediate feedback and visual cues are more helpful in solving design-problems containing spatial information. Based on these results, guidelines for effective use of different types of media in the construction industry were then developed as a final product of this study. These guidelines seek to improve awareness about the importance of effective communication in the construction industry

BriFiSeg: a deep learning-based method for semantic and instance segmentation of nuclei in brightfield images

Generally, microscopy image analysis in biology relies on the segmentation of individual nuclei, using a dedicated stained image, to identify individual cells. However stained nuclei have drawbacks like the need for sample preparation, and specific equipment on the microscope but most importantly, and as it is in most cases, the nuclear stain is not relevant to the biological questions of interest but is solely used for the segmentation task. In this study, we used non-stained brightfield images for nuclei segmentation with the advantage that they can be acquired on any microscope from both live or fixed samples and do not necessitate specific sample preparation. Nuclei semantic segmentation from brightfield images was obtained, on four distinct cell lines with U-Net-based architectures. We tested systematically deep pre-trained encoders to identify the best performing in combination with the different neural network architectures used. Additionally, two distinct and effective strategies were employed for instance segmentation, followed by thorough instance evaluation. We obtained effective semantic and instance segmentation of nuclei in brightfield images from standard test sets as well as from very diverse biological contexts triggered upon treatment with various small molecule inhibitor. The code used in this study was made public to allow further use by the community

Development of truck weight limits for concrete bridges using reliability theory Desenvolvimento de equações para a limitação do peso de veículos de carga em pontes de concreto através da teoria de confiabilidade

The increase in gross weight limits allowed by Brazilian legislation and the soaring number of new truck configurations on national highways has called for greater attention regarding the structural safety of bridges when submitted to real traffic. This paper verifies the performance of bridges under Sao Paulo Department of Transportation jurisdiction using the reliability index β and obtains truck weight limits in order to guarantee structural integrity. The superstructures of reinforced and prestressed concrete bridges, classes 36 and 45, are considered. The ultimate limit state is verified in cross sections subjected to positive and negative critical bending moments. In case of prestressed bridges, the cracking limit state in concrete is added. The real traffic is represented by a live load model based on weighting data collected from stations located on highways of the state of Sao Paulo and the statistical resistance parameters are determined using the Monte Carlo technique. The gross weight limits are presented in the form of equations known as bridge formulas which are applicable to any group of two or more consecutive axles. The observed results indicate restrictions to the traffic of some vehicles, especially the 740 kN and 19.80 meters length truck. Considering only the serviceability limit state, class 45 bridges are found to exhibit lower weight limits due to the load factors recommended by the code during design. O aumento nos limites de peso estabelecidos pela legislação brasileira e a proliferação das Combinações de Veículos de Carga nas rodovias nacionais motivam uma preocupação no que se refere à segurança estrutural das pontes quando submetidas ao tráfego real. Este trabalho verifica o desempenho das obras-de-arte especiais sob jurisdição do DER-SP através do índice de confiabilidade β e obtém equações para a limitação do peso de caminhões de modo a não comprometer sua integridade estrutural. São consideradas as superestruturas das pontes em concreto armado ou protendido, classes 36 e 45. Verifica-se o estado limite último nas seções transversais mais solicitadas por momento fletor positivo e negativo. No caso de pontes em concreto protendido, acrescenta-se a verificação do estado limite de formação de fissuras. O tráfego real é representado por um modelo de carregamento móvel baseado em pesagens de caminhões efetuadas em rodovias do estado de São Paulo e os parâmetros da resistência são determinados através da técnica de Monte Carlo. Apresenta-se os limites de peso em forma de equações, denominadas ECPLs (Equações Comprimento-Peso Limite), aplicáveis a quaisquer grupo de eixos consecutivos dos veículos. Os resultados indicam restrições à circulação de algumas composições, especialmente ao rodotrem de 740 kN e 19,8 metros de comprimento. Considerando-se apenas o estado limite de serviço, as pontes classe 45 apresentam menores limites de peso devido à ponderação de ações durante o projeto

Estruturas mistas no contexto da pré fabricação: alternativa à ligação viga-laje pré-fabricada.

O intenso processo de industrialização sofrido pela construção civil nos últimos anos está associado à busca por sistemas estruturais e/ou construtivos que visem à racionalização da construção, entre os quais se destacam os sistemas mistos de aço e concreto. Um sistema misto de aço-concreto visa extrair o máximo desempenho dos materiais. Para tanto, é necessário que se garanta a melhor interação possível entre os materiais. Nesse contexto, o comportamento das conexões entre os elementos de aço e concreto pré-fabricado, é um fator determinante na escolha do sistema construtivo. O presente trabalho apresenta e discute soluções para a conexão entre a viga metálica e a laje de concreto, tendo como enfoque as ligações por aderência. São apresentadas tanto soluções que utilizam conectores do tipo Pino, mais usuais, até às mais recentes soluções, no caso, as ligações por aderência, que tem se demonstrado bastante promissora em termos de resistência. Por fim, são apresentados resultados específicos de novas soluções para a conexão viga-laje, no contexto de uma solução pré-fabricada.The intense process of industrialization suffered by construction in recent years is associated with the search for structural and/or constructive systems aiming the rationalization of construction, among which stand out the composite systems of steel and concrete. A composite system of steel-concrete aims to extract maximum performance of materials. Therefore, it is necessary to ensure the interaction between these materials. In this context, the behavior of connections between elements of steel and precast concrete is a determining factor in the choice of the structural system. This paper presents and discusses solutions to the connection between the steel beam and concrete slab, with the focus on the connections by adherence. Are presented as solutions that utilize stud connectors, more usual, as the latest solutions, connections by adherence, which has been shown quite promising in terms of strength. Finally is presented specific results of new solutions for the beam-slab connection in the context of prefabrication

Experimental analysis of new interfaces for connections by adhesion, interlocking and friction.

The authors thank the federal agency CAPES and the Foundation for Research Support of the state of Sao Paulo, Brazil (FAPESP) for providing a PhD scholarship, and the University of Minho, in Portugal, for the international collaboration.This paper presents the results of an experimental program developed to investigate the behavior of an innovative technology for connections by adhesion, interlocking and friction in composite structures. Connections have a strategic importance for precast concrete and steel–concrete composite structures, since they determine the global structural behavior and affect the whole production process, fromexecution to assemblage and other services on site. Currently, however, steel–concrete composite connections are not completely adapted for their use in prefabricated slabs. In this way, the development of new types of connections is clearly necessary, where connections by adherence (or connections by adhesion, interlocking and friction) seem quite promising. To improve the knowledge in the field of connections by adherence, this paper proposes a new geometry of embossments in the steel and in the concrete surfaces associatedwith the use of a high performance mortar.Monotonic push-out tests are performed, and their results are presented and discussed. A satisfactory behavior of the proposed connection in terms of strength is observed, justifying further studies on the subject.CAPES, FAPES

Almofadas de apoio feitas de argamassa para ligações de concreto pré-moldado: estudo da rugosidade superficial

Bearing pads are used in precast concrete connections to avoid concentrated stresses in the contact area between the precast elements. In the present research, the bearing pads are Portland cement mortar with styrene-butadiene latex (SB), lightweight aggregate (expanded vermiculite-term) and short fibers (polypropylene, glass and PVA), in order to obtain a material with low modulus of elasticity and high tenacity, compared with normal Portland cement mortar. The objective of this paper is to analyze the influence of surface roughness on the pads and test other types of polypropylene fibers. Tests were carried out to characterize the composite and test on bearing pads. Characterization tests show compressive strength of 41MPa and modulus of elasticity of 12.8GPa. The bearing pads tests present 30% reduction of stiffness in relation to a reference mortar. The bearing pads with roughness on both sides present a reduction up to 30% in stiffness and an increase in accumulated deformation of more than 120%, regarding bearing pads with both sides smooth

Tests on composite beams using new connections by adherence

Cast in place concrete is often the cheapest solution in the context of conventional construction. However, prefabrication presents advantages in terms of execution time, quality of the structural elements and cost. Thus, the association of precast concrete elements and steel sections in a composite element can result in a high quality structure, executed with greater speed and economy of financial and material resources. Currently, steel to concrete composite connections are not completely adapted to prefabricated slabs and the use of connections by adhesion, interlocking and friction seem quite promising. To improve the knowledge in this field, this paper presents the development of full scale flexural tests of composite beams using new interfaces for these connections, and their results are interpreted and discussed. For comparison purposes, two beams with cast in place slab are tested. A satisfactory behavior in terms of strength is observed, in both cases investigated (cast in place and precast slab), justifying further studies on the subject.info:eu-repo/semantics/publishedVersio

Registro de imóveis

Divulgação dos SUMÁRIOS das obras recentemente incorporadas ao acervo da Biblioteca Ministro Oscar Saraiva do STJ. Em respeito à Lei de Direitos Autorais, não disponibilizamos a obra na íntegra.Localização na estante: 347.235(81) R337iCoordenado por: Martha El Debs e Izaías Gomes Ferro Júnio

Diretrizes para processo de projeto de fachadas com painéis pré-fabricados de concreto em ambiente BIM

Este artigo expõe as diretrizes para a criação de um processo de elaboração de projetos que utilizam painéis pré-fabricados de fachada, tendo como base o ambiente de Building Information Modeling (BIM). Os painéis pré-fabricados arquitetônicos de concreto (PPAC) foram utilizados como ponto de partida para a estruturação da proposta. A lógica de montagem justifica esta abordagem: assim como no sistema construtivo pré-fabricado, em que as peças são construídas fora do canteiro e chegam a este no momento da montagem, em BIM, os componentes da indústria da Arquitetura, Engenharia e Construção (AEC) são modelados independentemente e inseridos no momento oportuno no modelo. Foram realizados estudos teóricos sobre as características dos PPACs, seguidos de consulta a profissionais experientes do setor, para confirmação da seleção de dados e procedimentos necessários para o projeto. Em seguida, elaboraram-se fluxogramas de orientação para o processo de projeto. Uma simulação do procedimento proposto foi feita com o programa Revit 2013, para validação. A proposta procura auxiliar o projetista a definir os passos de projeto, bem como os dados para a modelagem dos elementos. Ao auxiliar projetistas a conceber projetos utilizando elementos pré-fabricados, procura-se facilitar e estimular seu uso mais frequente no país

Design of concrete-filled steel tubular columns under axial loading according to NBR 8800:2008 and Eurocode 4:2004: tests results and comparisons

São apresentados os resultados experimentais de 32 pilares mistos preenchidos de seção circular, submetidos à compressão axial, para os quais foi avaliada a influência dos seguintes parâmetros: resistência à compressão do concreto, relação comprimento/diâmetro (L/D) e espessura do tubo de aço (t). Os valores experimentais de força máxima foram comparados com aqueles resultantes da aplicação da formulação apresentada na NBR 8800:2008 e no EN 1994-1-1:2004 (Eurocode 4 - EC4), extrapolando-se os resultados para valores de resistência do concreto não previstos por essas normas. Os perfis de aço com relação comprimento/diâmetro (L/D) de 3, 5, 7 e 10 foram preenchidos com concretos de resistências à compressão de 30, 60, 80 e 100MPa. Os resultados da comparação entre valores de força última experimental e teórica mostraram que as normas avaliadas apresentam bons resultados. A NBR 8800 apresenta resultados conservadores ao passo que o EC4 apresenta, em média, valores de força resistente não conservadores. A correlação tende a piorar para concretos de resistência menor.In this paper results of tests on 32 concrete-filled steel tubular columns under axial load are reported. The test parameters were the concrete compressive strength, the column slenderness (L/D) and the wall thickness (t). The test results were compared with predictions from the codes NBR 8800:2008 and EN 1994-1-1:2004 (EC4). The columns were 3, 5, 7 and 10 length to diameter ratios (L/D) and were tested with 30MPa, 60MPa, 80MPa and 100MPa concrete compressive strengths. The results of ultimate strength predicted by codes showed good agreement with experimental results. The results of NBR 8800 code were the most conservative and the EC4 showed the best results, in mean, but it was not conservative for usual concrete-filled short columns.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) - Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP