Concrete is a material used in various applications, involving paving, sanitation, infrastructure and superstructure works, dams, bridges, and architectural elements, but for certain applications their physical and mechanical properties are affected by intense degradation agents, motivating the search for artifacts that improve these properties and increase the useful life and durability of matrix materials cement industry. The objective of this work is to clarify the influence of different mix of superplasticizer, steel fibers, water/cement factor, different types of mineral admixtures, besides the type of thermal treatment and method of cylindrical concrete molds of reactive powders, evaluating the resistance to axial compression at the ages of 7 and 14 days. 17 compositions were defined, by mass, for the manufacture of concretes, divided into two stages: the first composed of 10 compositions, and the second by 7 compositions. It was used CP-V ARI cement, sand, metakaolin, silica fume, superplasticizer and kneading water with temperature between 1 and 3°C. After the conformation of the cylindrical molds of dimensions 5x10cm with the aid of a portable immersion vibrator, the specimens were unmolded after 24 hours and received thermal treatment with periods of pre-cure and isotherm that varied according to the defined trait. According to the results obtained, the reduction of the w/c factor and the superplasticizer additive presented higher resistance to compression, however, this reduction in an excessive way impairs the hydration process, implying in the incomplete hydration of all the cement particles, resulting in less resistance. It was observed that the application of thermal treatment and densification by means of layer immersion vibrators acted as essential factors in the increase of the resistances, and that the isotherm time of the composite corroborates the respective increase, until its stabilization, in the temperatures studied.

The exponential advancement of cutting-edge technologies in the scope of civil construction, seeks to give cement-based materials the eco-efficient potential linked to mechanical performance that enables different applications. This work aims to evaluate the glass residue regarding the pozzolanic potential through ABNT NBR 5752:2014, as well as to verify whether through the characterization tests of x-ray fluorescence, x-ray diffraction and laser diffraction granulometry, if it is viable of application as supplementary cementitious material (filler), in ultra-high performance concrete. The glass residue submitted to the tests proposed in this study, was crushed in a jaw crusher, milled in a bench ball mill at 47 rpm, and was sieved in a 75 µm opening mesh (ABNT nº 200 mesh). For the test of pozzolanic activity, CP II F-40 class cement, normal sand, water from the public supply network, and superplasticizer additive were used for the mix with 25% of the residue replacing cement, while for the other characterization techniques, the glass residue was applied in its processed form (after sieving), dry or wet. The evaluated glass residue did not reach the minimum rate of 75% established by ABNT NBR 5752:2014, achieving only 45.72%, being classified as non-pozzolanic, which indicates its inert behavior in the presence of calcium hydroxide. The characterization tests confirmed, based on the specialized literature on ultra-high performance concrete, its viability as a filler when adopted as an alternative raw material for presenting chemical and mineralogical composition, in addition to granulometric distribution, very close to those used in studies that demonstrated satisfactory results when using the glass residue as an input.

RESUMONeste trabalho é analisado o dimensionamento ótimo de sistemas de microaspersão, através de um modelo de otimização utilizando-se programação não linear, com o objetivo de minimizar os custos de investimento e operacional, para três cenários de demandas hídricas obtidas em duas localidades da Região Nordeste do Brasil: Iguatu, CE, com os balanços hídricos anual e mensal, e João Pessoa, PB, com balanço hídrico mensal. O modelo tem como variáveis de decisão: os comprimentos dos trechos de tubos com seus respectivos diâmetros, o tempo total diário de irrigação, a uniformidade de emissão, a freqüência de irrigação e a pressão média de operação do emissor. Os resultados evidenciaram que em regiões de clima semi-árido, como Iguatu, não há diferenças importantes no dimensionamento do sistema com as demandas obtidas através do balanço hídrico anual ou mensal. O custo de investimento não foi afetado pelas demandas, mas apenas os custos operacional e total do sistema. Regiões com menor requerimento hídrico diário e anual, como João Pessoa, permitem maior número de unidades operacionais do sistema e, portanto, maior redução dos custos de investimento, porém para um mesmo número de subunidades e de unidades operacionais as diferenças de demandas hídricas não afetam o dimensionamento. A máxima demanda hídrica diária da cultura tem maior efeito sobre a hidráu-lica do sistema do que a demanda hídrica anual. O sistema com dimensionamento ótimo depende da análise conjunta do número de subunidades e de unidades operacionais do sistema e não se pode desprezar o custo da energia.Palavras-chave: evapotranspiração, microaspersão, modelo de otimização, custos, hidráulica Microirrigation system design through non linear programming considering different water demands ABSTRACTIn this work the optimum microsprinkler system design is analyzed through optimization model using non linear programming, with the objective of minimizing operational and investment costs, for three sceneries of the water demand in two localities of the Northeast region of Brazil: Iguatu, Ceará State, with annual and monthly water balances, and João Pessoa, Paraíba State, with monthly water balance. The model has as decision variables: the lengths of the pipe sections with their respective diameters, the daily irrigation total time, the emission uniformity, the irrigation frequency and the emitter mean operation pressure. The results evidenced that in semi-arid climate areas, as Iguatu, there are not important differences in the design system with the demands obtained through the annual or monthly water balances. The investment cost was not affected by the demands, but just the operational and total system costs. Regions with smaller daily and annual water requirement, as João Pessoa, allow larger number of operational units of the system and, therefore, larger reduction of the investment cost. However, for same number of the subunit and operational units the water demands differences do not affect the design. The maximum daily water demand of the crop has l...

Water supply systems are fundamental to society and are increasingly being demanded in terms of quantity and quality of water. In addition to these two aspects, which are the basis of the service provided, other issues have generated a lot of pressure, environmental preservation, the quality of service from companies, and costs to consumers. The improvement in the provision of the service and the reduction of costs necessarily involves the improvement of the system’s operation. The energy cost of pumping is one of the factors that most affect the operating cost of the systems. The relevance of the cost of energy with pumping motivated this work. Through computational modeling, we sought to minimize the costs of a real pumping system. Nonlinear programming and the genetic algorithms of the Excel solver tool were applied to obtain the optimal cost of pumping. The decision variables of the model were the 24-hour pump operation intervals. The main restrictions are to respect the limits of the reservoirs and the recovery of levels at the end of the 24-hour cycle. Both techniques were able to find viable solutions, however, the evolutionary algorithms confirmed their slowness in relation to the generalized reduced gradient (GRG). In both techniques, peak hours were minimally allocated to the operation. Regarding the studied system, it was found that the main responsible for the operational cost is the transport of water treatment plants (WTP) to R5, approximately 81,69%, and there is a limitation in the pumping capacity that prevents the complete shutdown of the pumps during peak hours. In the present study, the following specific consumptions were obtained: elevatory station EE 1 (ETA-R5) 0.897kWh/m³; EE 2 (R5-R4) 0.16 kWh/m³; EE 3 (R4-RLS) 0.617037 kWh/m³ and EE 4 (R4-RC) of 0.471852 kWh/m³. Considering the average of the subsystem studied, there are 0.537 kWh/m³, EE 2 (R5-R4) being more efficient, and less efficient EE 1 (ETA-R5). This can be justified by the greater demand and because it is necessary to operate at peak hours with high-powered pumps. Investment in improving the system is necessary to increase its energy efficiency and, consequently, reduce the high costs of the operation.

<p>O dimensionamento de sistemas de irrigação exige a análise de muitas alternativas para que se obtenha a opção mais viável técnica e economicamente, o que requer na maioria das situações o auxílio de modelos computacionais. Existem diversos modelos computacionais disponíveis para o dimensionamento e análise de redes hidráulicas, mas com uso mais difundido no meio acadêmico. Neste trabalho, faz-se uma apresentação do modelo computacional denominado EPANET-IRRIG versão 1.0, que é um aperfeiçoamento do software EPANET 2.0, no qual foram inseridas novas funcionalidades que dizem respeito à melhoria de interface e, principalmente, ao desenvolvimento de um módulo para o dimensionamento hidráulico-econômico e a avaliação de redes hidráulicas. Os primeiros resultados <br />obtidos com o EPANET-IRRIG já permitem ao usuário confiabilidade para o dimensionamento e a avaliação de sistemas de irrigação por gotejamento, microaspersão e aspersão. A interface criada para o módulo de irrigação permite agora que extensas redes, com numerosos pontos emissores, sejam mais facilmente modeladas. Os custos da rede de irrigação e da energia podem ser detalhadamente identificados, permitindo uma análise mais criteriosa do projeto com grande versatilidade.</p>