Navegando por Autor "LIMA, Alexandre Martins de"

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Análise estatística do comportamento mecânico à compressão do compósito cimento-madeira
(2011) MACÊDO, Alcebíades Negrão; LIMA, Alexandre Martins de; FONSECA, Fábio de Oliveira; LAVÔR, Bárbara Valéria de Abreu
The present work has the objective to propose the use of saw dust wood waste from the tropical wood industry mainly located at Belém, Pará State, for the fabrication of wood-cement composites. Due to the natural chemical incompatibility between wood and cement, this procedure results in a set retarding effect, with wood specie depending intensity. This by-effect can be overcome by using procedures such as additives, wood mineralization, accelerated carbonation and others. Analysis were made based on axial compression strength data with samples aged 28 days for mortars made with 2, 3.5 and 5% wood content in mass, using cements type CP I and CP II, with and without Calcium Clorets-based set accelerator additive. The data there from obtained was statistically analyzed to evaluate the influence of the wood content and of additives on the mechanical strength. Most of the research works developed so far make use of reforestation waste, very little being available about tropical wood waste. So, this work represents a pioneer effort in developing a cement-bonded wood composite with regionally available materials and residues from Belém, Pará State.
Acesso aberto (Open Access)
Influência de três tipos de tratamentos físicos na resistência à compressão de compósitos cimento-madeira à base de resíduos de serraria
(Universidade Federal do Pará, 2005-09-20) LIMA, Alexandre Martins de; AGUIAR, Osmar José Romeiro de; http://lattes.cnpq.br/5816019774493244; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179
In the present research work, the effect of the type of physical treatment in the resistance to compression of composites cement-wood was analyzed. Residues of variegated compositions (hardwood) collected at sawmills of the Metropolitan area of Belém were used, and the effects of the following treatments were studied: drying in stove, thermal bath and the mineralization with aluminum sulfate. The first step of the research was the survey of the theoretical references as support for the experimental program. Next, the constituent materials of the composite were characterized according to methods prescribed by the Brazilian Norms and after being homogenized, lab tests were carried out in the fresh state. The tests in the hardened state were driven in such a way that the mechanical characteristic observed for the evaluation of the effect of the referred treatments was the tensile strength. The results indicated that the used residues inhibit the hydration of the cement matrix, as well as they influence the resistance negatively the tensile strength. The residues treated with drying in stove provided the smallest resistances to the compression observed for the composites; the treatment of thermal bath and the treatment of mineralization presented better results. However, even presenting a slight difference among the medium values for the rupture tensions, they presented statistical equivalence, and they corroborated the statement that the treatment typology used in the residues is preponderant factor to mitigate the harmful effects of the extractives of the wood in the resistance to compression of the mortars.
Acesso aberto (Open Access)
Pelos trilhos dos bondes: cidade, modernidade e tensões sociais em Belém de 1869 a 1947
(Universidade Federal do Pará, 2011-05-30) LIMA, Alexandre Martins de; ACEVEDO MARIN, Rosa Elizabeth; http://lattes.cnpq.br/0087693866786684
This investigation aims to analyze the spatial and social changes that happened in belém, through the tramway perspective, from 1869 to 1947. In this context, tramways appear as symbols of modernity and as locus where daily social phenomena could be observed, such as gender relations, social dominations and resistance, territorialization of urban space – partially generated by the gentrification process – the varying degrees of sociability and affectivities and social behaviors tacitly established, or imposed by posture codes. Thus, historical materialism is used as the main methodological support. Subjects like social distinction, social classification and symbolic power were analysed using Bourdieu´s concepts and categories. The processual sociology of Norbert Elias was also used to interpretate social phenomena, wich gave linearity to this investigation. The investigation has focused on three axes: the city´s history, the everyday life´s history, and tramway´s history. As a mean of interpreting the city´s history and daily life, the literature was used, regional mainly, and official reports from the city and tram companies, the media discourse and memory stories. We concluded that tramways changed their user´s perception of space and time, reproduced social group´s differences, provided new forms of sociability, fostered the growth of the city and connected the territories of a gentrified city.