Utilização do resíduo grosso do beneficiamento da scheelita em aplicações rodoviárias

Mining is an activity of great economic and social value, assisting in the development of the country. However, it can be extremely harmful to the environment if no proper waste management study exists as mitigation measure its effects. Sample some of these harmful effects are pollution: water, through the seepage of waste into the groundwater; soil; of fauna and flora; sound (due to the noise of machines); visual from the residue stored in the open, changing the local landscape; and air. One way to mitigate environmental impacts caused by mining is the proper management of their waste through their use on highways. To that end, this paper proposes to give an appropriate destination to grit coming from the beneficiation of scheelite, due to mining activity from mining group Tomaz Salustino in Brejuí mine, located in the city of Currais Novos in the state of Rio Grande do Norte. This work was developed in four stages. The first comprised the chemical and mineralogical tests, DRX and FRX in which they sought to discover the composition of the material studied. The next step involved the physical characteristics of the waste by means of specific tests and grinding the solid mass, LL and LP. The third stage included the specific tests applied to the pavement, with the compaction test and test Index Support California. Finally, the fourth stage was the mechanical characterization, represented by direct shear tests, both in the flooded condition and not in flooded condition. The technical feasibility of using the modified energie compacted in layers of subbase power has been verified. In normal and intermediate energies is feasible to use less noble as layers as the subgrade. The incorporation of the waste in layers of road pavements provide an alternative to conventionally used in paving aggregates, providing a proper disposal of tailings from scheelite, as well as environmental preservation

Caracterização de resíduos oriundos do beneficiamento do minério de ferro para uso em pavimentação

Mining in Brazil has a key role in economic and social development, contributing directly to improve the lives of the population. However, the mining activity even if done responsibly and with a proper study of waste management to reduce the impact of its effects, may cause harmful damage to the environment. Other forms of pollution are also caused due to mining activity. The visual pollution caused by the waste storage at open sky, in addition to the noise pollution caused by the excessive noise of the machines both in the extraction of ore, as in processing. An alternative way to lessen the environmental impacts caused by mining is the use of waste in layers that will compose the pavements along the highways. Thus, this work sets out to give a proper disposal of the wastes from the processing of iron ore, resulting from the mining activity of the group of mining Mhag Services and Mining S/A, in the mine of Bonito, located in Jucurutu, a town in the state of Rio Grande do Norte. The residues of the iron ore were stabilized with a granular soil from the city of Macaiba, also in the state of Rio Grande do Norte, which is being used in the duplication of the BR-304 referring to the entitled passage of Reta Tabajara. The present work was developed in three stages, being the first one divided by the chemical and mineralogical tests, by the tests of physical characterization and by the tests of paving for the residues of the iron ore. The second stage corresponds to the same tests being performed for granular soil. The third stage includes the essays abovementioned for three different mixtures of iron ore waste and granular soil, being they: 15% of iron-ore waste and 85% of granular soil, 25% of iron-ore waste and 75% of granular soil, 50% of iron-ore waste and 50% of granular soil. The technical feasibility of using waste from the iron ore beneficiation was checked, compressed in the intermediate energy and modified for use in base layers, sub-base, reinforcement subgrade and subgrade. The incorporation of the residues originating from the improvement of the iron ore in highways will provide an alternative to the use of aggregate conventionally used in the paving, besides preserving the environment.

Vitalidade no centro antigo Teresina, Piauí Praça Marechal Deodoro: uma intervenção contemporânea em área de valor patrimonial

This study deals with the discussions of contemporary interventions in public spaces in areas of heritage value. The product of this dissertation is an Intervention Project to Marechal Deodoro Square located in Teresina/PI center. The starting point for understanding the theme of this study is to investigate the accessibility and vitality of a public space - through relationship between form and uses. The spatial properties of accessibility and visibility as well as the distribution of land use - factors were associated with distinct patterns of vitality - and compared to usage patterns observed in situ and statements from users obtained through the results of the questionnaires. In attention to questions about the building constructed, particularly in historical centers, considers the guidelines to define intervention strategies in the square, consisted in the development of simulations that after evaluation of results of redesign, was chosen the best option to meet the necessary requirements to the performance, considering the spatial properties of integration and visibility that meet these requirements. Therefore, the "Intervention Project" carried out for the Marechal Deodoro Square characterization proposed items are discussed: spatial structure, vegetation, road network, pavements, street furniture and lighting

Calçadas invisíveis: aspectos do passeio público, em Natal-RN, como projeção de uma cidadania ausente

This study has as a goal to establish a relationship between public sidewalk characteristics of Lagoa Nova District (neighborhood), in Natal and the kind of citizens whose constructions and maintenance layouts reflects. It‟s understood here as public sidewalk, specifically, the place reserved for passers-by traffic, located between public lots and vehicles pavements. It‟s a concern to make a brief survey about the occupation of this particular region and a detailed description over physical characteristic of its sidewalks that shows several obstacles for passers-by accessibility, trying to find possible factors that explain the problematic format , once, at the first sight, most of accessibility of passers-by is compromised. It‟ also, searched, local population thoughts regarding occupation notions about this environment, just like as cultural, political and economical aspects that might influence upon snatching these hybrid places located between private and public border line. It‟s confirmed that the nowadays sidewalks‟ shapes is not only citizenship reflection or a lack of it but shows it as an active agent related with the construction of this set of fundamental rights and duties vital for harmonical co-living local citizens

Provas de carga estática com carregamento lateral em estacas escavadas hélice contínua e cravadas metálicas em areia

An experimental study has been conducted to investigate the behavior of continuous flight auger (cfa) bored piles and metalic driven H-section piles under lateral loading in cohesionless soils. The piles were tested in two different areas at the same site. Both areas consisted of a 3-m thick compacted superficial fill of pure fine sand, underlain by layers of naturally occurring pure fine-thick sand. Fills are differentiated by the relative densities which were compressed, 45% e 70%, respectively. Each area received one identical pair of cfa piles and two identical pairs of H-piles. A static lateral loading test was performed in each pair of piles. In this work, the pile load test results are reported and interpreted. The horizontal coefficient of subgrade reaction was determined from the results of the loading tests and compared with values determined by correlations based on penetration resistance index of SPT tests (NSPT). p-y formulations describing the static behavior of the piles were applied to the problem under evaluation. Back Analyses were made through theoretical and experimental p-y curves for obtaining input parameters for the analytic models, among which the coefficient of horizontal reaction. The soil pile system horizontal loading at rupture was determined by the theoretical methods and the results were compared with the experimental results, checking its validity

Reciclagem de material asfáltico fresado utilizando solventes e microemulsões

With the increase of asphalt milling services was also a significant increase in recycling services pavements. The techniques used today are basically physical processes in which the milled material is incorporated into new asphalt mixtures or executed on site, with the addition of virgin asphalt and rejuvenating agent. In this paper seeks to analyze the efficiency of extraction of CAP (Petroleum Asphalt Cement) mixtures from asphalt milling, using commercial solvents and microemulsions. The solvents were evaluated for their ability to solubilize asphalt using an extractor reflux-type apparatus. Pseudoternary diagrams were developed for the preparation of microemulsion O/W surfactant using a low-cost coconut oil saponified (OCS). Microemulsions were used to extract the CAP of asphalt through physicochemical process cold. Analysis was performed concentration of CAP in solution by spectroscopy. The data provided in the analysis of concentration by the absorbance of the solution as the basis for calculating the percentage of extraction and the mass flow of the CAP in the solution. The results showed that microemulsions prepared with low concentration of kerosene and butanol/OCS binary has high extraction power of CAP and its efficiency was higher than pure kerosene, reaching 95% rate of extraction

Obtenção de emulsões asfálticas convencionais e modificadas com argilas e nanoargilas

The increasing demand for asphalt leads to the development of techniques that can improve the quality of products and increase the useful working life of pavements. Consequently, there is a growing application of asphalt emulsions, which are produced from a mixture of petroleum asphalt cement (CAP) with an aqueous phase. The main advantage of asphalt emulsions is its cold application, reducing energy costs. Conventional emulsions are obtained using asphalt, water, solvent, and additives. The modified asphalt emulsion is developed by adding a modifying agent to conventional emulsions. These modifiers can be natural fibers, waste polymers, nanomaterials. In this work modified asphalt emulsion were obtained using organoclays. First, it was prepared a conventional asphalt emulsion with the following mass proportion: 50% of 50/70 penetration grade CAP, 0.6% of additives and 3% of emulsifier, 20% of solvent and 26.4% of water. It was used bentonite and vermiculite (1% and 4%) to obtain the modified asphalt emulsion. Bentonite and vermiculite were added in its raw state and as an organoclay form and as an organoclay-acid form, resulting in 26 experimental runs. The methodology described by Qian et al. (2011), with modifications, was used to obtain the organoclay and the organoclay-acid form. infrared spectroscopy (IR)) were used to characterize the clays and nanoclays. The emulsions were prepared in a colloidal mill, using 30 minutes and 1 hour as mixing time. After, the emulsions were characterized. The following tests were performed, in accordance with the Brazilian specifications (DNER- 369/97): sieve analysis, Saybolt Furol viscosity, pH determination, density, settlement and storage stability, residue by evaporation, and penetration of residue. Finally, it can be concluded that the use of nanoclays as asphalt modifiers represent a viable alternative to the road paving industry

Viabilidade técnica da fabricação de compósito utilizando fibra de pneu na fabricação de blocos intertravados

This work aims to demonstrate the feasibility of a ceramic composite containing fiber in the rubber manufacturing interlocking blocks. Gravel, sand, cement, rubber and fiber: the processes of manufacture and assembly of blocks produced and the various formulations studied with different proportions between the constituent elements were addressed. Mechanical properties were determined for the different formulations, compressive strength, diametral compressive strength, water absorption and apparent density, obeying the rules related to each property. It was concluded that the addition of rubber fiber gave the concrete studied resistance lower than conventional concrete which can be verified on the microstructural analysis obtained by SEM, which revealed the presence of pores and the low adhesion between the fiber and the matrix compression (tire fiber / cement paste). The composite of more viable tire BCPB1 (1/2) fiber can be used in places requests as light squares, pavements, roads and other cycle as well as in the manufacture of the curb and gutter, by having compressive strength in about 20 MPa

Vitalidade no centro antigo Teresina, Piauí Praça Marechal Deodoro: uma intervenção contemporânea em área de valor patrimonial

This study deals with the discussions of contemporary interventions in public spaces in areas of heritage value. The product of this dissertation is an Intervention Project to Marechal Deodoro Square located in Teresina/PI center. The starting point for understanding the theme of this study is to investigate the accessibility and vitality of a public space - through relationship between form and uses. The spatial properties of accessibility and visibility as well as the distribution of land use - factors were associated with distinct patterns of vitality - and compared to usage patterns observed in situ and statements from users obtained through the results of the questionnaires. In attention to questions about the building constructed, particularly in historical centers, considers the guidelines to define intervention strategies in the square, consisted in the development of simulations that after evaluation of results of redesign, was chosen the best option to meet the necessary requirements to the performance, considering the spatial properties of integration and visibility that meet these requirements. Therefore, the "Intervention Project" carried out for the Marechal Deodoro Square characterization proposed items are discussed: spatial structure, vegetation, road network, pavements, street furniture and lighting