Otimização do tempo e temperatura no processamento da gipsita oriunda dos cristalizadores da produção de sal para obter gesso de uso na construção civil

During the process of the salt production, the first the salt crystals formed are disposed of as industrial waste. This waste is formed basically by gypsum, composed of calcium sulfate dihydrate (CaSO4.2H2O), known as carago cru or malacacheta . After be submitted the process of calcination to produce gypsum (CaSO4.0,5H2O), can be made possible its application in cement industry. This work aims to optimize the time and temperature for the process of calcination of the gypsum (carago) for get beta plaster according to the specifications of the norms of civil construction. The experiments involved the chemical and mineralogical characterization of the gypsum (carago) from the crystallizers, and of the plaster that is produced in the salt industry located in Mossoró, through the following techniques: x-ray diffraction (XRD), x-ray fluorescence (FRX), thermogravimetric analysis (TG/DTG) and scanning electron microscopy (SEM) with EDS. For optimization of time and temperature of the process of calcination was used the planning three factorial with levels with response surfaces of compressive mechanical tests and setting time, according norms NBR-13207: Plasters for civil construction and x-ray diffraction of plasters (carago) beta obtained in calcination. The STATISTICA software 7.0 was used for the calculations to relate the experimental data for a statistical model. The process for optimization of calcination of gypsum (carago) occurred in the temperature range from 120° C to 160° C and the time in the range of 90 to 210 minutes in the oven at atmospheric pressure, it was found that with the increase of values of temperature of 160° C and time calcination of 210 minutes to get the results of tests of resistance to compression with values above 10 MPa which conform to the standard required (> 8.40) and that the X-ray diffractograms the predominance of the phase of hemidrato beta, getting a beta plaster of good quality and which is in accordance with the norms in force, giving a by-product of the salt industry employability in civil construction

Estudo do comportamento plástico, mecânico, microestrutural e térmico do concreto produzido com resíduo de porcelanato

Population growth experienced in major cities, allied to society s need of infra-structure, especially ones related to habitational demands, increases the consumption of construction materials. As a consequence, consumption of natural resources itself. Thus, due to this process, concrete is one of the most produced materials in civil construction. This is also due to the great diversity of its application, easiness in its execution and adequate mechanical performance, as well as low production costs. Following the same tendencies in construction development, the ceramic industry has intensified the production of porcelain ceramic tiles and floors. These are achieved by a fine finishing and receive polishing at the end of the fabrication process. This work researched the use of porcelain residues in polishing for the production of concrete. All of which; due to economical and environmental issues. This process aims to prove adequate destiny for this type of residue, due to environmental issues, incorporating it to the concrete itself; all of which provides economy in consumption of the materials that constitute concrete. Thus, the main characteristics of concrete were investigated through the inclusion of different concentration of the porcelain residue as additional trait element. The residue rates incorporated to the trait varied from 10% to 50% in relation to the cement mass, in the traits with plastic additives and without plastic additives. It is observed that the inclusion of porcelain residue produced a meaningful alteration in the consistency of fresh concrete. This residue has a fine granulometry and it considerably absorbed the water used in the concrete spreading, influencing the way this material is dealt with. Thus, the value of cement striking decreases with the increase of residues present in trait. The maximal incorporation of the residue was of 50%, massively, for the same factor water/initial cement. The use of residues in concrete results in an 40% increase in the compression resistance. It is also proportional to residue concentration of porcelain in the trait. The microstructure was also favored once porosity and concrete absorption decreases with the use of this residue. The parameters demonstrate the quality and durability of the concrete produced with this residue. The use of porcelain residue in concrete composition has not produced meaningful thermal behavior changes. Thermal conductivity, heat capacity and thermal diffusivity have been maintained basically constant

Gestão da cadeia de fornecimento :um estudo em empresas de construção certificadas com a ISO 9000

The aim of this present research is to investigate about aplication of the supply chain management in Civil Construction, through perception of brasilian building companies directors. Research purpose includes potential benefits and main dificults analysis in supply chain management, beyond to identify decision criterions for suppliers and sales chain (commission agent and real state agency) choice and reduction, to facilility management in companies. The methodology used in this work considers the application of a questionnaire with scales of the type Likert being constituted of variables that compose the aspects of evaluation and of behaviors, beyond questions to identify the market profile of the respondents. For analysis statistics is used the descriptive, clusters and variance, ANOVA, analysis last two to verify the connections between variables. The results show more perception as for long terms contracts with suppliers for purchase of materials and services being decisive for companies nowadays (40%) than as for exclusive contracts with commission agents (30%). There is a positive appraisal about viability of hipotetic situations showed, but more caution as for disposition to apply them too. Another results aim for biggers dificults in management of chain links formed by commission agents and real state agencies, than chain links formed by anothers suppliers of materials and services. The companies for study were chosen among to those with ISO 9000 certificate until november 2001, considering that these companies have the best management systems, probably

Estudo do comportamento plástico, mecânico, microestrutural e térmico do concreto produzido com resíduo de porcelanato

Population growth experienced in major cities, allied to society s need of infra-structure, especially ones related to habitational demands, increases the consumption of construction materials. As a consequence, consumption of natural resources itself. Thus, due to this process, concrete is one of the most produced materials in civil construction. This is also due to the great diversity of its application, easiness in its execution and adequate mechanical performance, as well as low production costs. Following the same tendencies in construction development, the ceramic industry has intensified the production of porcelain ceramic tiles and floors. These are achieved by a fine finishing and receive polishing at the end of the fabrication process. This work researched the use of porcelain residues in polishing for the production of concrete. All of which; due to economical and environmental issues. This process aims to prove adequate destiny for this type of residue, due to environmental issues, incorporating it to the concrete itself; all of which provides economy in consumption of the materials that constitute concrete. Thus, the main characteristics of concrete were investigated through the inclusion of different concentration of the porcelain residue as additional trait element. The residue rates incorporated to the trait varied from 10% to 50% in relation to the cement mass, in the traits with plastic additives and without plastic additives. It is observed that the inclusion of porcelain residue produced a meaningful alteration in the consistency of fresh concrete. This residue has a fine granulometry and it considerably absorbed the water used in the concrete spreading, influencing the way this material is dealt with. Thus, the value of cement striking decreases with the increase of residues present in trait. The maximal incorporation of the residue was of 50%, massively, for the same factor water/initial cement. The use of residues in concrete results in an 40% increase in the compression resistance. It is also proportional to residue concentration of porcelain in the trait. The microstructure was also favored once porosity and concrete absorption decreases with the use of this residue. The parameters demonstrate the quality and durability of the concrete produced with this residue. The use of porcelain residue in concrete composition has not produced meaningful thermal behavior changes. Thermal conductivity, heat capacity and thermal diffusivity have been maintained basically constant

Adição de superplastificante e anti-segregante à base de CMC em pastas de cimento para Poços de Petróleo

Oil well cementing materials consist of slurries of Special class Portland cement dispersed in water. Admixtures can be used to provide the necessary fluidity, so the material can be efficiently pumped down as well as penetrate porous rocks with controlled filter loss. Construction admixtures can be used to modify the properties of oil well cements provided they can withstand and hold their properties at the higher than ambient temperatures usually encountered in oil fields. In civil construction, superplasticizer play the role of dispersants that reduce the facto r of water cement improve mechanical properties and fluidity of the cement, whereas anti-segregation agents improve the workability of the slurry. In the present study, oil well cement slurries were produced adding both a dispersant and an anti-segregation agent conventionally used in Portland CPII-Z-32 RS cement aiming at materials for primary cementing and squeeze operations. Three basic aspects were evaluated: fluidity, filter loss and the synergetic effect of the admixtures at two temperatures, i.e., 27°C and 56°C, following API RP 10B practical recommendations. The slurries were prepared using admixture concentrations varying from 2.60 Kgf/m3 (0.02 gallft3) to 5.82 Kgf/m3 (0.045 galJft3) BWOC. The density of the slurries was set to 1.89 g/cm3 (15.8 Ib/gal). 0.30 to 0.60% BWOC of a CMC-based anti-segregation agent was added to the cement to control the filter loss. The results showed that the addition of anti-segregation at concentrations above 0.55% by weight of cement resulted in the increased viscosity of the folders in temperatures evaluated. The increasing the temperature of the tests led to a reduction in the performance of anti-segregation. At concentrations of 5.20 kgf/m3 (0,040 gallft3) and 5.82 Kgf/m3 (0,045 gal/ft 3) observed a better performance of the properties evaluated in the proposed system. At low temperature was observed instability in the readings of rheology for all concentrations of anti-segregation. Contents that increasing the concentration of anti¬-segregation is limited concentrations greater than 0.55 % BWOC of the CMC in temperature analyzed. The use of the system with CMC promoted a good performance against the properties evaluated. The principal function of anti¬-segregation was optimized with increasing concentration of superplasticizer, at temperatures above the 2rC. The study of the behaviour of systemic additives, resulting in slurries of cement, which can be optimized face studies of other intrinsic properties in oil fields

Desenvolvimento de sistemas de aditivos químicos para aplicação em cimentações de poços de petróleo

The primary cementing is an important step in the oilwell drilling process, ensuring the mechanical stability of the well and the hydraulic isolation between casing and formation. For slurries to meet the requirements for application in a certain well, some care in the project should be taken into account to obtain a cement paste with the proper composition. In most cases, it is necessary to add chemicals to the cement to modify its properties, according to the operation conditions and thus obtain slurries that can move inside the jacket providing a good displacement to the interest area. New technologies of preparation and use of chemicals and modernization of technological standards in the construction industry have resulted in the development of new chemical additives for optimizing the properties of building materials. Products such as polycarboxylate superplasticizers provide improved fluidity and cohesion of the cement grains, in addition to improving the dispersion with respect to slurries without additives. This study aimed at adapting chemical additives used in civil construction to be used use in oilwell cement slurries systems, using Portland cement CPP-Special Class as the hydraulic binder. The chemical additives classified as defoamer, dispersant, fluid loss controller and retarder were characterized by infrared absorption spectroscopy, thermogravimetric analyses and technological tests set by the API (American Petroleum Institute). These additives showed satisfactory results for its application in cement slurries systems for oil wells. The silicone-based defoamer promoted the reduction of air bubbles incorporated during the stirring of the slurries. The dispersant significantly reduced the rheological parameters of the systems studied. The tests performed with the fluid loss controller and the retarder also resulted in suitable properties for application as chemical additives in cement slurries

Representações sociais sobre o acidente de trabalho em saúde

The aim of the present study was to identify the representational elements of workrelated accidents in the health field, as well as investigate their most frequent occurrences at a university hospital, seeking to understand the cognitive, affective and social elements subjacent to the work process involved in health. The analysis focused on 470 middle and senior support staff of this hospital, based on the theoretical-methodological support of the Social Representations Theory. A combination of the following instruments was used for data collection: a free wordassociation test, a questionnaire, an interview and a field journal. Evoc 2000 software was used to identify representational structure. Chi-square and Mann-Whitney tests, at a significance level of 5%, were performed to verify the association between the independent variables and the occurrence of work accidents. In addition, thematic content analysis and lexicographic analysis by ALCESTE software program were used to understand textual content. It was observed that social representations of work-related accidents in the health area are centered in the contamination category, while the categories of prevention and professional unpreparedness are found peripherally. There was a significant association between the existence of multiple employment, the use of personal protective equipment (PPI) during work, job satisfaction and the occurrence of work accidents. The conclusions indicate that perforating-cutting occupational accidents predominated in the hospital and that the representations of the subjects intertwined, with a traditional discourse of work accidents strongly present in Occupational Health. It is therefore suggested that certain subjective aspects related to culture, in terms of controlling work accidents, such as: management, process, organization and the increasing precariousness

Adição de superplastificante e anti-segregante à base de CMC em pastas de cimento para Poços de Petróleo

Oil well cementing materials consist of slurries of Special class Portland cement dispersed in water. Admixtures can be used to provide the necessary fluidity, so the material can be efficiently pumped down as well as penetrate porous rocks with controlled filter loss. Construction admixtures can be used to modify the properties of oil well cements provided they can withstand and hold their properties at the higher than ambient temperatures usually encountered in oil fields. In civil construction, superplasticizer play the role of dispersants that reduce the facto r of water cement improve mechanical properties and fluidity of the cement, whereas anti-segregation agents improve the workability of the slurry. In the present study, oil well cement slurries were produced adding both a dispersant and an anti-segregation agent conventionally used in Portland CPII-Z-32 RS cement aiming at materials for primary cementing and squeeze operations. Three basic aspects were evaluated: fluidity, filter loss and the synergetic effect of the admixtures at two temperatures, i.e., 27°C and 56°C, following API RP 10B practical recommendations. The slurries were prepared using admixture concentrations varying from 2.60 Kgf/m3 (0.02 gallft3) to 5.82 Kgf/m3 (0.045 galJft3) BWOC. The density of the slurries was set to 1.89 g/cm3 (15.8 Ib/gal). 0.30 to 0.60% BWOC of a CMC-based anti-segregation agent was added to the cement to control the filter loss. The results showed that the addition of anti-segregation at concentrations above 0.55% by weight of cement resulted in the increased viscosity of the folders in temperatures evaluated. The increasing the temperature of the tests led to a reduction in the performance of anti-segregation. At concentrations of 5.20 kgf/m3 (0,040 gallft3) and 5.82 Kgf/m3 (0,045 gal/ft 3) observed a better performance of the properties evaluated in the proposed system. At low temperature was observed instability in the readings of rheology for all concentrations of anti-segregation. Contents that increasing the concentration of anti¬-segregation is limited concentrations greater than 0.55 % BWOC of the CMC in temperature analyzed. The use of the system with CMC promoted a good performance against the properties evaluated. The principal function of anti¬-segregation was optimized with increasing concentration of superplasticizer, at temperatures above the 2rC. The study of the behaviour of systemic additives, resulting in slurries of cement, which can be optimized face studies of other intrinsic properties in oil fields

Desenvolvimento de sistemas de aditivos químicos para aplicação em cimentações de poços de petróleo

The primary cementing is an important step in the oilwell drilling process, ensuring the mechanical stability of the well and the hydraulic isolation between casing and formation. For slurries to meet the requirements for application in a certain well, some care in the project should be taken into account to obtain a cement paste with the proper composition. In most cases, it is necessary to add chemicals to the cement to modify its properties, according to the operation conditions and thus obtain slurries that can move inside the jacket providing a good displacement to the interest area. New technologies of preparation and use of chemicals and modernization of technological standards in the construction industry have resulted in the development of new chemical additives for optimizing the properties of building materials. Products such as polycarboxylate superplasticizers provide improved fluidity and cohesion of the cement grains, in addition to improving the dispersion with respect to slurries without additives. This study aimed at adapting chemical additives used in civil construction to be used use in oilwell cement slurries systems, using Portland cement CPP-Special Class as the hydraulic binder. The chemical additives classified as defoamer, dispersant, fluid loss controller and retarder were characterized by infrared absorption spectroscopy, thermogravimetric analyses and technological tests set by the API (American Petroleum Institute). These additives showed satisfactory results for its application in cement slurries systems for oil wells. The silicone-based defoamer promoted the reduction of air bubbles incorporated during the stirring of the slurries. The dispersant significantly reduced the rheological parameters of the systems studied. The tests performed with the fluid loss controller and the retarder also resulted in suitable properties for application as chemical additives in cement slurries

Desenvolvimento de cerâmica vermelha utilizando rejeitos da construção civil

The Industry of the Civil Construction has been one of the sectors that most contribute to the pollution of the environment, due to the great amount of residues generated by the construction, demolition and the extraction of raw material. As a way of minimizing the environmental impacts generated by this industry, some governmental organizations have elaborated laws and measures about the disposal of residues from the building construction (CONAMA - resolution 307). This work has as objective the reutilization of residues compound of sand, concrete, cement, red bricks and blocks of cement and mortar for the production of red ceramic, with the objective of minimizing costs and environmental impacts. The investigated samples contained 0% to 50% of residues in weight, and they were sintered at temperatures of 950°C, 1000°C, 1050°C, 1100°C and 1150°C. After the sinterization, the samples were submitted to tests of absorption of water, linear retraction, resistance to bending, apparent porosity, specific density, XRD and SEM. Satisfactory results were obtained in all studied compositions, with the possible incorporation of up to 50% of residues in ceramic mass without great losses in the mechanical strength, giving better results to the incorporation of 30% of residues in the fabrication of ceramic parts, such as roofing tiles, bricks masonry and pierced bricks

Gestão ambiental e competitividade no setor da construção civil :um estudo sobre a aceitabilidade de práticas ambientais no mercado imobiliário

This work investigates the importance of Eco-Materiais applied in the civil construction and the necessity of knowledge of the real estate market, showing the importance of application of recycled products where inserted inside of a bigger scope of the sustainable development which has the subjects as the ambient management. In the theoretical referencial boarded the recycled and perfectly ecological products that demonstrate the applicability of this type of products in the sector of the civil construction, beyond the economic and social placesThe main popouse of the real estate sector is to show the awareness and demonstration in the negotiation of property constructed with these products, therefore, already it is practised by the market of the civil construction where much time sao commercialized by real estate and the its correctors lacking in same knowledge that is more deepened on these materials, having this evidence been made with statistical application of questionnaire and analyzed with base. We finish showing the statistical results with application of 142 questionnaires in a universe of 145 real estate from Natal/RN. With this, we may say that today exists a very strong concern with the environmental laws and the generated ambient impact in the civil construction and that the real estate sector has a feeling that the necessity of if inserting in this process, therefore, the real estate market in our State is in expansion and sensible to the necessity of changes, since the Natal/RN meets in the script of the tourism the International demanding of the professional that a globalized knowledge works with property, so the necessity of understanding the environmental laws and understanding application of the echo-materias used in the construction will give a better quality of life and at the same time to protect the nature

Desenvolvimento de um sistema de indicadores de desempenho para empreendimentos em construção civil, utilizando a abordagem macroergonômica

This paper presents the validation of the Performance Indicator System for Projects under Construction - SIDECC. The goal was to develop a system of performance indicators from the macroergonômica approach, considering criteria of usefulness, practicality and applicability and the concept of continuous improvement in the construction industry. The validation process SIDECC consisted of three distinct models. Modeling I corresponded to the theoretical development and validation of a system of indicators. Modeling II concerns the development and validation of multi- indicator system. For this modeling, we used the Mother of Use and Importance and Multivariate Analysis. Modeling III corresponded to the validation situated, which consisted of a case study of a work of construction of buildings, which were applied and analyzed the results of modeling II. This work resulted in the development of an applied and tested for the construction of an integrated system of performance indicators methodology, involving aspects of production, quality, environmental, health and safety. It is inferred that the SIDECC can be applied, in full or in part, the construction companies as a whole, as well as in other economic sectors

Estudo da Potencialidade da produção de tijolos de adobe misturado com outros materiais: uma alternativa de baixo custo para a construção civil

The production of the red pottery brick, made traditionally with clay, is a technique that is already stabled. However, in spite of the little complexity that involves the conventional process of these bricks production, it are exposed to many problems that begin in the fase of exploration of the mines, the problems get worse because of the lack of the clay's characterization, and they continue through the steps of the dough preparation, conformation of the products, the drying and the burning process. The wastefulness is shown and so is the low quality of the material produced. Among other factors, the high use of energy in the burning makes the cost of this material inaccessible to the low income consumer. Besides this, the destruction of the environment around the mines and the use of native vegetation to produce wood - the most used fuel in the pottery industry - make serious environmental damage. The production technique of a new type of simple brick (adobe), that has low cost and no environmental damage, can be the viable altemative to lower the cost of this part of the civil construction, and, consequently, in the building of cheaper houses. In this paper, the results of the mechanical resistance of the adobe brick are shown, using in its composition, clay, natural vegetable fibers, cement and plaster in a process that is completely handcrafted and manual. It is intented to make clear that are possible alternatives to be put in practice, with the simple process, using "raw earth" that has been used in the construction of houses in thousands of years, trying to solve these severe problems. Analysis and tests were performed to find results that could prove the possibility of the utilization of this kind of material. Other studies are in progress, and the new researches are necessary to enrich this work, but it stays the certainty that there is potential to produce bricks from adobe, as an alternative that has low cost to civil construction

Desenvolvimento de um sistema de indicadores de desempenho para empreendimentos em construção civil, utilizando a abordagem macroergonômica

This paper prese nts the validation of the Performance Indicator System for Projects under Construction - SIDECC. The goal was to develop a system of performance indicators from the macroergonômica approach, con sidering criteria of usefulness , practicality and applicabilit y and the concept of continuous improveme nt in the construction industry . The validation process SIDECC consisted of three disti nct models . Modeling I corresponded to the theoretical development and valid ation of a system of indicators . Modeling II concern s the development and valida tion of multi - indicator system . For this modeling, we used the Mother of Use and Importance and Multivariate Analysis . Modeling III correspo nded to the validation situated , which consisted of a case study of a wo rk of construct ion of buildings , which were applied and anal yzed the results of modeling II . This work resulted in the development of an applied and tested for the construction of an integrated system of per formance indicators methodology , involving aspects of production , quality , e nvironmental, health and safety . It is inferred that the SIDECC can be applied, in full or in part , the construction companies as a whole, as we ll as in other economic sectors .

Significado do trabalho para trabalhadores da construção civil

The meaning of work is a construct that has been studied more systematically from the 80s, through various approaches and in different occupational categories. This dissertation aims to describe and discuss the meanings of work for construction workers. This is an empirical study whose research supports herself in the Model Attributes Meaning of Work and its respective instrument for measuring the Meaning of Work Inventory (STI). The research involved 402 workers in the construction industry sector in the two capitals of the Brazilian Northeast, with a mean age of 35.8 years (SD = 11.4). To collect the data, besides the IST, the Working Conditions Questionnaire and sociodemographic data were also used. Data were organized and analyzed using the SPSS program. The study used data analysis techniques to Smallest Space Analisys (SSA), descriptive statistics, correlation and analysis of variance. There was evidence of validity of the STI which was structured into five types of value attributes (what work should be), and seven types of descriptive attributes (what is working). The results showed that the work has high centrality and profiling for participants after the family, the most important aspect in the lives of workers. Aspects of personal and economic growth were more emphasized in definition of what the work should be and responsibility and effort were characteristics that best described the reality of work.