Análise de misturas solo-agregado reciclados de resíduos sólidos da construção civil, para fins de pavimentação de vias urbanas de baixo volume de tráfego

This work deals with the continuation of Scientific Initiation research initiated by Tamura (2012), which draws up a mixture of soil and recycled aggregate analysis for paving of low traffic volume roads using local materials from the Vale do Paraíba region. The main steps of the process were the soil and recycled aggregate characterization, along with grading tests and California Bearing Ratio (CBR) applied to the soil, the recycled aggregate and the mixture of soil and recycled aggregate; aiming their use as base and sub-base in paving urban roads. The results are discussed, emphasizing the mechanical behavior. The current results are compared with the results of IC Tamura research, taking decisions over this job to the final product best result. For a greater understanding of the work in general were described paving, its structure, its components and its physical behavior. It has been intended to emphasize the importance of the mixture of soil and recycled aggregate to meet the quality requirements and compliance with the specifications of current technical standards, in the context of durability, natural materials economy, decreases volume in landfills and cost reduction

Caracterização da liga Ti-15Zr visando aplicações biomédicas

With advances in health care, has been na increase of demand for material that could replace the functions of the human body parts, thus evolved biomedic prosthesis which today are responsible for the constant improvement of the quality of life. The Titanium alloys are widely used as implants due to its properties, like high mechanical resistance, biocompatibility and corrosion resistance, and the addition alloying elements like Zirconium, may improve some of those properties. Such properties are related to the microstructure and consequently to the type of processing performed. The purpose of this dissertation was to characterize the experimental alloy Ti15Zr after route of processsing and heat treatment in order to extend the knowledge about this alloy. The latter has been abtained by fusion of pure metals in a arc melting furnace with an inert argon atmosphere. The material has been homogenized in a tube furnace at 950ºC for 24h and cold worked by swaging, after that, bars with 10 mm of diameter were obtained by the process of rotary forging. The samples were solubilized at 900º C for 2 hours and quenched in water. After that, 4 samples were submitted to the aging, at 400º C, 450º C, 500º C and 550º C. The microstructure and phase analysis was done by optical microscopy and X-rays diffraction (XRD), the mechanical characterization was carried out by microhardness test and finally, evaluation of corrosion resistance of the alloy by electrochemical tests. The XRD and the optical microscopy made it possible to analyze that the heat treatment influenced the phase shifting from α to α', and probably affected the alloy hardness, at the first aged sample at 500º Chas been a sudden increase in the value of hardness, probably by appearance of omega phase, unwanted phase to the medical application duo to great fragility, and finally ... (Complete abstract click electronic access below)