RCAAP Repository

The rapid urban growth in many Brazilian cities in the twentieth century occurred without the proper planning and infrastructure. In these cities, floods cause great material and human losses every year. Therefore, the authorities and community must propose and implement flood control measures after detailed studies of the characteristics of the watershed . Thus, hydrological simulations of the stream Jataí watershed located in Uberlândia/MG, was performed using the software ABC - Complex Watershed Analysis, from the University of São Paulo considering the return period of 100 years for the project rain. This watershed has an area of 15.99 km² and was discretized by sub-basins considering the land use and occupation at the current urbanization and critical scenario (fully urbanized and occupied basin). The damping reservoir existent in the study area were considered in the simulations and it was proposed the implementation of a parallel damping reservoir near to the watershed output. The sub-basins 02 and 08 simulated alone at the critical scenario provided the highest maximum flow rates of 193.17 and 162.78 m³/s respectively. Furthermore, the damping reservoirs 02 and 05 showed the largest decreases of input hydrogram peak flow with maximum reductions of 86.3 and 76.6% respectively at the current urbanization scenario. The implementation of the proposed parallel damping reservoir allowed the reduction of peak flows at the basin outlet of 26.8% from 211.65 to 154.87 m³/s in the current scenario and 22.3% reduction from 262.28 to 203, 86 m³/s at the critical urbanization scenario. Based on these results, it is possible to conclude that the damping reservoirs are very important to control runoff and it is necessary and urgent to implement new flood control measures in the Jataí stream watershed to reduce the inconvenience caused by heavy intensity rains.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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

The safety fundamental principle of reinforced concrete structures related of a possible collapse is that the security does not depend on the concrete resistance tensile strength to eliminate the risk of collapse without notice. The cracking caused by tensile stresses can affect the concrete structure and should be avoided to the natural structural collapse doesn t occur. The diagonal crack that appears on the act of breaking is called critical crack, characteristic of shear failure. In this work were experimentally studied the additional mechanisms from the shear resistant trusses in reinforced concrete frames without transverse reinforcement. The experimental experiments consists on testing eight frames that were subjected to a simple bending. Two concrete grades of characteristic the compressive strength were considered on the construction of the frames. To resist the bending stresses, the frame s beams are designed in the field 3 of the ultimate limit states. Different rates and diameters of longitudinal reinforcement were used. In all frames weren t considered the use of transverse reinforcement in the region of shear on the beams. From the results obtained were analyzed the proposed criteria to define the portion of the contribution for the shear resistance mechanisms of concrete without the use of transverse reinforcement and the influence of the concrete resistance and longitudinal reinforcement rates in the numerical results experimentally obtained.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

The use of concrete walls in single-family buildings had greatly increased in recent years. To meet the demand of housing construction of social interest and the need to improve performance, business construction have sought new construction systems being one of them the walls of reinforced concrete with self compacting concrete or entrained air. The evolution of the use of concrete walls culminated in the publication, in May 2012, the NBR 16055. The purpose of this paper is to present the results of a survey on the actual performance of air incorporated into plates, considering the climatic variations of the period winter. The control variable is the heat conduction gradient, aiming the thermal performance of housing. The experimental program consisted of performing panels 16 (quantity determined by ANOVA), and reference 4 and 4 for each dose developer air additive (0.04%, 0.08% and 0.12% on the cement consumption ). The thermal test was conducted in a chamber with two thermally insulated compartments and independent control of temperature (10 oC to 25 oC) and relative humidity. The partition between the two compartments the plates were placed. They determined the physical properties in fresh and hardened specimens and the behavior of each group with respect to thermal conduction. For the percentage of additive used, the total air content ranged from 2.8% to 11.88% and the frustoconical rebate increased from 21 mm to 107 mm. The results showed that the density decreased to 11% when incorporated additive. The compressive strength had reductions of up to 53% at 28 days of age and the modulus of elasticity also reduced by 26%. In the thermal test, with a chamber ranging from 10 ° C to 25 ° C and maintained at 10 ° C another, the concrete with additive was 0.04% with a temperature of approximately 1.5 ° C lower than the reference concrete.

The aim of this work is to study the economic-financialviability to deploy and operate a paratransit network to meet demands of commuting trips for employees of a private company in Uberlândia, MG. The study was developed based on employees who leave in the Santa Mônica neighborhood, whose addresses were geocoded and inputted on a digital map. The information was inputted in the TransCAD software in order to determine clusters corresponding to bus stops considering the maximum walking distance for passengers to have access to the service. Optimization studies of routing and trip times were done, taking into account the vehicle capacity as a parameter, which allowed for the scheduling of the transportation service. Once calculated the operational parameters, the fares were calculated by using the methodology adopted by GEIPOT. In the end, it was performed an economic and financial viability of implementing and operating the paratransit service. It was compared the amounts incurred by the company in funding the Vale-Transporte Program with those indicated in the farestudies. The work concluded that the company could deploy and maintain their own network to transport its employees, with equivalent costs, if compared to Vale-Transporte Program, and higher service level, if compared to regular bus service.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

This work aimed to study the incorporation of ceramic residues of tiles crushed in the soilcement mixture in the manufacture of hollow blocks, justified by the amount of these wastes generated by the ceramic tile industry, with potential for recycling. This study aimed to determine a molding energy in laboratory compatible with that of the hydraulic presses of the factory. The DNER-ME 258:1994 test method compacted soils miniature equipment Mini-MCV were used , observing that it is possible to mold bodies of proof in laboratory with ASDM apparent specific dry mass compatible with that of the hollow blocks produced in the factory. Four lots of soil-cement hollow blocks were produced, whose tests allowed to choose the most appropriate mixture, the desired value of ASDM and the number of compatible blows. The ASDM of soil-cement bodies and the blocks were compared, and there was compatibility of values. To study mixtures with the RTA Recycled Tile Aggregate the optimization methodology of the volumes of materials was used in order to fill the gaps in the aggregate with compacted soil-cement. Starting from the gap indices of the aggregate containing cement and the pure aggregate the work began with two soil-cement aggregate mixtures. By projection, other mixtures resulted from these, which, after tests, allowed to select the most adequate. Using this one, hollow blocks were manufactured, whose test results met the standard with regard to strength, but not to water absorption. To reduce the absorption, a waterproofing additive, a stabilizer and an Aloe Vera extract were inserted in the mixture, whose bodies of proof tests registered values within the normative limits in 2 cases. Hollow blocks using the most favorable mix amount were produced, whose tests attended the strength requirements, but not the absorption ones. The results obtained indicate the feasibility of the methods, and that RTA can be used for manufacturing hollow blocks, although this depends on the pressing capability of the factory.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Many researches have applied the Analytical Hierarchical Process (AHP) technique created by Saaty (1980), in the multicriterial analysis related to management of water and environmental resources. Among these works, highlight the vulnerability analysis proposed by Ross (1994) which became a reference for many other researchers in Brazil. The use of AHP technique has gained importance in environmental studies because of its association with geographic information systems to assign different degrees of susceptibility classes to morphogenesis and pedogenesis variables on a map. What is not appear in the literature is an assessment of the influence of experience and other human conditions in the initial consideration of the technical implementation and that may incur subjectivity in the analysis. Therefore, this research proposes to apply the method of artificial neural network (ANN) as a way to refine the weights indicated by experts in the application of AHP technique and minimize the subjectivity of the analysis process. In this research the AHP technique results are ponderations ass proposed by Ross (1994), by local experts through questionnaires and the application of ANN in determining the map of environmentally vulnerable areas of the watershed Córrego do Fundo, Carmo do Paranaíba, MG (Brasil). The results allow affirming applicability of RNA's to reduce the subjectivity of the data obtained with the AHP method has relevant consistency.

Conventionally the floors mortar are composed of ground mineral aggregates that mixed with Portland cement have extensive use in large enterprises. In this work was evaluated the possibility to aplicate glass waste to replace the mineral aggregates used in the manufacture of polished floors. Samples were produced with natural aggregate, used as reference, and plates with glass waste with two types of cement. The objective was to determine the physical and mechanical performance of the offered material, allied with the recycling of glass residue. Tests were conducted of water absorption, deep abrasion and bending test. Accelerated test of alkali aggregate reaction was realized on the samples to assess the possibility of alkali-silica reaction. Posteriorly, we realized analyse scanning electron microscopy and X ray diffraction. At the end there was not loss in properties in terms of water absorption and deep abrasion, in the samples produced with glass residue in relation to the samples produced with natural aggregate. There was only reduction in the flexural strength in the results obtained at 180 days of age. Among the samples produced with glass waste, was found high possibility of occurrence of the Alkali Silica Reaction in the samples produced with CPII F40, that occurred less expressive may, in the samples produced with CPIV 32.

This dissertation presents the study of one-way slabs formed by lattice joist with and without prestressing. The objective of this study is to compare the technical performance of each structural solution, taking into account the prestress competitiveness. For the slab design procedure and the optimization analysis, a routine is developed in an electronic spreadsheet. Some parameters such as loading, length between the axis, strength of concrete, steel area and prestressing force is considered in the analysis. The optimization process is carried out with two objectives. The first is to obtain a design whose final displacement is equal to the limit value prescribed by ABNT NBR 6118:2014. The second objective is to obtain the maximum vertical displacement that minimize the slab weight. The slab is considered simple supported and formed by individual beams. The results shows that the use of the lattice prestressed joists, to spans such as 6 m to 9 m, the average weight reduction of the slab is around 21% compared to not prestressed joists. It is concluded that, for the restrictions imposed in this study, the maximum span for the design of slabs with not prestressed joists is around 9 m, while for the prestressed situation the limit is around 15 m.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior