Repositório RCAAP

The present work aims to study the waffle slabs taking into account the simplifications in the analysis of their behavior. The simplifications used concern the analysis of waffle slab by the equivalent solid slab, the considerations on the flexibility of the support beams, and the treatment of continuity between adjacent panels of slabs. The research supports in the experimental analysis, in the results of studies published, in the standard codes for design of reinforced concrete to base the simplifications adopted. One waffle slab in actual size and its equivalent solid slab are tested. The test results for the waffle slab are compared with the processing of the slab through computer programs for structural design. The costs of slabs in two buildings are compared when it adopts the simplified analysis method or grillage model.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

In the mid-sixties there was a boom in civil construction and at that moment it was possible to observe a considerable increase in the activities in this area. Similarly, we currently witness an important period in civil construction in Brazil, in which a great amount of investment was made by the Federal Government, allowing the construction of large-scale in all the national territory, principally of the Social Interest Dwellings (SID). This overview demonstrated that the constructive methods have to be developed for the completion of the chronograms, the improving of the quality and the reduction of environmental impact. However, as well as in previous decades, great part of the systems adopted in Brazil still refer to traditional construction processes and, according to what was determined by CAIXA, they are called conventional processes, that is, performed with constructive systems that have already been regulated. In the Triangulo Mineiro region is not different, great part of the constructions of the SID refer to the conventional way, executed with structures and foundations in reinforced concrete, ceramic blocks of masonry sealing, mortared coating in a single layer and wood covering structures with ceramic tiles. The point is that the conventional systems normally have a series of deficiencies related to the conception of the product, the insufficient project detailing and the enormous dependency on the knowledge of the labor execution workers. The pattern establishing is clearly difficult, together with the high level of labor using and the consequent low level of mechanization; the bad quality of some materials, principally the ones resulted from the direct nature extraction; and mostly, the incomplete projects and the inexistence of planning, do not permit the civil construction to be executed, practically speaking, in a rational way. Therefore, the reason why so many companies that construct the SID choose the traditional processes is questioned, even knowing that it is necessary to reach a more sustainable production in terms of the environment, increase the quality and the productivity in construction. This way, it is necessary to turn the attention to the improvement of quality and the rising of the industrialization level of the traditional constructive processes, which still represent a great part of the market, as well as the search of implementation of non-conventional constructive processes. Due to this demand, this work presents the analysis of the implications of adopting such processes in the execution of the SID in large scale, through the analysis of projects, procedures and losses in the productive process of a one-story-dwellings enterprise, executed in the city of Uberlandia, aiming the rationalization to obtain better results in quality and less generation of waste.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

The increasing demand for raw materials in construction, especially those drawn from nature, is of great concern due to harmful impacts it produces. The use of recycled aggregates can be a sustainable and contribute to the preservation of natural resources, contributing to the sustainable development of the construction industry. The residue from the ceramic tile has been studied for various applications, attracting great interest from researchers due to the need for innovation in materials and methods. Published works have identified the generation of waste from the manufacture of tiles, the ceramic industry in considerable amount thus justifying the need for its use. The self-compacting concrete - CAA is a material that has been used increasingly in construction, hence the interest in producing this type of recycled aggregate concrete with tile - ART. Previous studies have demonstrated the ability to produce recycled aggregate concrete tile (ART) with moderate resistance. This study aimed to evaluate properties in fresh and hardened state in a CAA produced with a fraction of thick ART and bystanders in thin 0.15 mm sieve opening of this same material, by the use of superplasticizer last generation as a way of adding value to this waste and contribute to the sustainability of the sector. The measurement was performed by a method developed for this type of aggregate based on existing methods. In the fresh state tests were performed density, air content embedded scattering, Box U test and test tube U. In the hardened condition assays were performed velocity of ultrasonic wave propagation, resistance to axial compression, static modulus of elasticity in compression, density, water absorption and void index. The results indicate that it is feasible to use in ART CAA for certain purposes.

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

The presents study results of the addition of sulfonated polystyrene, derived from discarded plastic cups as additive in mortars. The mortar were studied with polystyrene content of 0.0, 0.2, 0.6, 1.0 and 1.4% (relative to the mass of cement). CPV - ARI Portland cement and sand washed were used at rate 1:4 by weight. It was determined consistency index, water retention, water absorption, void index, static modulus of elasticity, compressive strength, tensile strength in bending and adhesion. The mortar modified with the additive showed increase in the porosity, tensile strength in bending, adhesion, plastic capacity and water retention. Furthermore the use of polystyrene leads to decrease in the density, the modulus of elasticity and in the capillary water absorption with increasing content of sulfonated polystyrene, which may indicate that even by increasing the number pores in the mortar, the pores are not communicated among themselves and the polymeric film had contributed for the mechanical properties.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

As the use of public transportation in medium and large cities becomes more and more popular, the number of urban bus stations connecting transport systems increases dramatically. As a result, the continuous traffic of heavy vehicles has produced disturbing noise levels inside the stations. Hence, the main goal of this research is to develop and implement statistical models for the prediction of the overall noise levels inside the bus stations. They are multiple regression models based on experimental data obtained from acoustic field measurements. In addition, some parameters are related to the noise generation and to the limits of acceptable community noise levels. It is also suggested an alternative solution to the problem by using noise control techniques at the source. The statistical models were then validated by comparing the results with those found in the literature. The main assumptions and limitations of the models are also discussed. This research was undertaken as a result of the need to improve the available analytical tools for the prediction of traffic noise inside buildings. There are significant opportunities for further development and implementation of the models derived in this study.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

The purpose of the work is to produce and characterize mechanically sandwich panels to using as ceiling in buildings. The faces of the panels were made of composites reinforced by ramie and sponge gourd fibers, and the cores were made of sponge gourd and expanded polystyrene-EPS. The faces of the sandwich panels were produced with different fiber contents, characterized for tensile mechanical properties and numerically simulated. The EPS and sponge gourd were studied as core materials. The flexural mechanical performance of the panels was tested experimentally and simulated by Finite Element Method. The numerical simulation was also used as tool for qualitative analyzes in the pre-design of the panel components considering variation of materials, fiber contents and thickness of faces and cores. The faces of the sandwich panels were manufactured with composite of polyester reinforced by ramie bidirectional cloth, and combined with the cores of EPS and sponge gourd. The results show the manufactured sandwich panels are feasible for use as ceiling.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior