Taciano Oliveira da Silva

MCT CLASSIFICATION FOR COMPACTED MIXTURES OF SOIL-STEEL SLAG-FLY ASH FOR APPLICATION IN FOREST ROADS

This work aimed to evaluate the potential application of a stabilizer derived from the intimate mixture of powder electric arc furnace oxidizing slag and fly ash, aiming at the improvement of soil engineering properties for enforcement purposes on forest roads. This evaluation was undertaken by means of an experimental program of laboratory tests to classify soils and mixtures of these with the proposed stabilizer according to the MCT (Miniature, Compacted, Tropical) methodology. The proportions of waste mixtures were 10% and 20% of the total dry mass of soil-waste combinations and percentages of ground steel slag were 75%, 87.5% and 100% relative to total dry mass of waste mixtures. It was shown the potential to technically enable the use of steel waste in the composition of forest roads, emphasizing the relevance of the proposal in meeting the need of steel companies to confer a sustainable destination for the waste and the need of forest companies to meet, with low-cost materials, the significant demands of their unpaved road network.

DOSAGEM DE MISTURA BETUMINOSA A FRIO E SEU ESTUDO SOB EFEITOS DE CARGAS ESTÁTICAS E REPETIDAS1

Este trabalho apresenta os resultados de uma pesquisa experimental que objetivou estudar o comportamento mecânico de uma mistura betuminosa a frio sob efeitos de cargas estaticas e repetidas. Apos a caracterizacao dos agregados e do ligante empregados na pesquisa, efetuou-se a mistura, a partir da dosagem Marshall, obtendo o teor de projeto equivalente a 8,5% de emulsao. Nesse teor de emulsao, moldaram-se varias amostras, que foram submetidas aos ensaios de modulo de resiliencia, resistencia a tracao por compressao diametral e fadiga. A caracterizacao dos agregados e do ligante mostrou-se concordante com varios estudos, exceto o residuo da peneiracao, que nao atendeu a exigencia do IBP (1999). Para os ensaios com as misturas asfalticas, empregaram-se tres corpos de prova, pesando cada um deles cerca de 1.200 g, compactados com 75 golpes em cada uma de suas faces. Observou-se que a estabilidade e a fluencia Marshall de 620 kgf e de 4,20 mm, respectivamente, superaram o limite minimo recomendado na especificacao de servico do DNIT (2010a). Com relacao aos ensaios de modulo de resiliencia e de resistencia a tracao por compressao diametral, obtiveram-se os valores de 1.616 MPa e 0,44 MPa, respectivamente, quando se verificou que os resultados foram bem inferiores aos encontrados em misturas a quente. Esse mesmo comportamento foi observado no ensaio de fadiga que, na maioria dos niveis de tensao aplicados, foi inferior a 1.000 aplicacoes do carregamento.

PROPOSTA METODOLÓGICA PARA MODELAGEM DIGITAL DE ELEVAÇÃO POR MEIO DE LASER SCANNING TERRESTRE COM ÊNFASE EM PROJETOS GEOMÉTRICOS DE VIAS

In order to propose and evaluate a processing routine for data from the equipment Terrestrial Laser Scanning (LST) to produce contour curves to be used in road geometric design, this study case developed an alternative route in the campus of the Federal University of Vicosa. Data collected were processed in the software RiSCAN PRO and ArcGIS. Contour curves were generated in both softwares, but two different interpolators were tested in ArcGIS, and statistical filters were applied to the best result using values of the nearest neighbors, the mean and the minimum. LST equipment was efficient for unvegetated sites, generating contour curves of high quality and accuracy. However, in vegetated areas, the filtering process was inefficient, leaving points above the terrain quota and overestimating the volumes of land movement in earthwork projects. The most efficient statistical filter was the one using the mean values, because it eliminated the noise in contour curves and did not skew the model produced. In conclusion, the LST equipment can be used in road geometric design, provided that it is accompanied by conventional topography in densely vegetated areas. Keywords: Contour Curves, Vegetation, Land movement.

MODELING A COMPUTER APPLICATION FOR MANAGEMENT OF MAINTENANCE ACTIVITIES OF UNPAVED ROADS

This study presents a contribution to the modeling of a computer application employing a method of serviceability performance for unpaved roads, aiming the management of maintenance/restoration activities of the primary surface layer. The proposed methodology consisted of field inspections during dry (April to September) and rainy (October to March) periods, during which objective evaluations were performed to survey of defects and their densities and degrees of severity. To aid the functional classification of analyzed road sections and the determination of the defect with major influence on the serviceability of these roads, the method of serviceability performance proposed by Silva (2009)was implemented in the Visual Basic for Applications (VBA) language in Microsoft Excel software. With the use of the computer application proposed it was possible to identify among the defects analyzed in field, through the index of serviceability of the sampling unit per defect type (ISUdef), which one had the greatest influence on determining the relative serviceability index per road section (IST). The results allow us to conclude that the computer application Road achieved satisfactory results, since the objective evaluation criteria applied to road sections denotes consistency regarding their serviceability.