ABSTRACT Flexible ureteroscopy is a well-established method for treatment of urinary stones but flexible ureteroscopes are expensive and fragile devices with a very limited lifetime. Since 2006 with the advent of digital flexible ureteroscopes a great evolution has occurred. The first single-use flexible ureteroscope was launched in 2011 and new models are coming to the market. The aim of this article is to review the characteristics of these devices, compare their results with the reusable devices and evaluate the cost-benefits of adopting single-use flexible ureteroscopes in developing countries. Materials and Methods: an extensive review of articles listed at PubMed and published between 2000 and 2021 was performed. Results: Single-use flexible ureteroscopes have a shaft with 65 to 68cm length and weight between 119 and 277g. Their deflection goes up to 300 degrees. Their stone-free rates vary between 60 and 95% which is comparable to reusable scopes and operative times ranges from 54 to 86 minutes which are lower when compared to reusable flexible scopes. Their costs vary between 800 and 3180 US dollars. Conclusion: single-use flexible ureteroscopes are lighter and have superior quality of image when compared to fiberoptic ones. There are no definite data showing a higher stone-free rate or less complications with the use of single-use flexible ureteroscopes. Each institution must perform a cost-benefit analysis before making the decision of adopting or not such devices depending on the local circumstances.

ABSTRACT Purpose: to evaluate the effect of low-calorie diet on 24-hour urinary metabolic parameters of obese adults with idiopathic calcium oxalate kidney stones. Materials and Methods: Adult idiopathic calcium oxalate stone formers, with body mass index (BMI) ≥30kg/m2 and a known lithogenic metabolic abnormality, were submitted to low-calorie diet for twelve weeks. After enrolment, anthropometric measures, serum exams, 24-hour urinary metabolic parameters and body impedance were collected one month prior to dietary intervention and at the end of twelve weeks. Correlations between weight loss, waist circumference loss, fat loss and variation in 24-hour urinary lithogenic parameters and calcium oxalate urinary supersaturation (CaOx SS) as per Tiselius equation were analysed. Results: From January 2017 to January 2018, 39 patients were enrolled to participate in this study. Median (range) prescribed diet was 1300 (1100-2100) Kcal/day. Mean age was 51.7±11.0 (29-68) years old and 69.2% were female. 30.8% of the participants shifted from obesity to BMI <30kg/m2 and none to BMI <25kg/m2. A significant correlation was found between baseline 24-hour urinary oxalate and weight (p=0.018) and BMI (p=0.026). No correlation was found between variation of weight, waist circumference, fat mass and 24-h urinary stone risk factors or CaOx SS. Conclusions: Short-term modest weight loss induced by twelve weeks of low-calorie diet is not associated with a decrease of 24-hour urinary lithogenic parameters in idiopathic calcium oxalate stone formers. Calcium oxalate urinary stone formation is probably multifactorial and driven by other factors than weight.

ABSTRACT Purpose: The objective of this study is to evaluate the impact of a previous standard percutaneous nephrolithotomy (PCNL) on the outcomes of retrograde intrarenal surgery (RIRS). Materials and Methods: Outcomes of RIRS performed from January 2017 to January 2020 in adult patients with residual stone fragments ≤20mm after a standard PCNL (Post-PCNL) and symptomatic adult patients with kidney stones ≤20mm (Control) were prospectively studied. Stone-free rate (SFR) was evaluated on a postoperative day 90 non-contrast computed tomography. Surgical complications based on Clavien-Dindo classification during the 90 days of follow-up were recorded. Results: Outcomes of 55 patients and 57 renal units of the post-PCNL group were compared to 92 patients and 115 renal units of the control group. SFR was lower in post-PCNL group than in control (28/57, 49.1% vs. 86/115, 74.8%, p <0.001). Overall complications were more frequent in post-PCNL group (p=0.004). Infundibula strictures were identified and incised with laser in 15/57 (26.3%) renal units of the post-PCNL group. Thirteen renal units had infundibulum stricture at the site of previous percutaneous tract (13/15; 86.7%, p=0.004) and one renal unit had three infundibula strictures. Postoperative complications were not affected by the treatment of infundibula strictures (p=0.198). Conclusions: Previous standard PCNL significantly impairs the outcomes of RIRS. Infundibula strictures can be found in 26.3% of the patients with residual stone fragments after standard PCNL for large burden kidney stones. The main site of infundibulum stricture after standard PCNL is the infundibulum of the entry calyx.

ABSTRACT Objective: The big data provided by Google Trends may reveal patterns in health information-seeking behavior on population from Brazil and United States (US). Our objective was to explore and compare patterns of stone disease online information-seeking behaviors in both nations. Materials and Methods: To compare Relative Search Volume (RSV) among different urologic key words we chose “US” and “Brazil” as country and “01/01/2009 - 31/12/2018” as time-range. The final selection included 12 key words in each language. We defined “ureteroscopy” as a reference and compared RSV against it for each term. RSV was adjusted by the reference and normalized in a scale from 0-100. Trend presence was evaluated by Mann Kendall Test and magnitude by Sen's Slope (SS) Estimator. Results: We found an upward trend (p <0.01) in most of the researched terms in both countries. Higher temporal trends were seen for “Kidney Stone” (SS=0.36), “Kidney Pain” (SS=0.39) and “Tamsulosin” (SS=0.21) in the US. Technical treatment terms had little search volumes and no increasing trend. “Kidney Stent” and “Double J” had a significant increase in search trend over time and had a relevant search volume overall in 2018. In Brazil, “Calculo Renal”, “Colica Renal”, “Dor no Rim” and “Pedra no Rim” had a significant increase in RSV (p <0.001). More common and popular terms as “Kidney Stent” and “Tamsulosin” were highly correlated with “Kidney Pain” and “Kidney Stone” in both countries. Conclusions: In the last decade, there was a significant increase in online search for medical information related to stone-disease. Population from both countries tend to look more for generic terms related to symptoms, the disease, medical management and kidney stent, than for technical treatment vocabulary.

ABSTRACT Purpose: To describe our experience in the management of retained encrusted ureteral stents using a single session combined endourological approach. Materials and Methods: Patients with retained encrusted ureteral stents who had been submitted to a single session combined endourological approach from June 2010 to June 2018 were prospectively evaluated. Patients were divided according to the Forgotten-Encrusted-Calcified (FECal) classification. The stone burden, surgical intervention, number of interventions until stone free status, operation time, hospital stay, complications, stone analysis, and stone-free rate were compared between groups. ANOVA was used to compare numerical variables, and the Mann-Whitney or Chi-square test to compare categorical variables between groups. Results: We evaluated 50 patients with a mean follow-up of 2.9±1.4 years (mean±SD). The groups were comparable in terms of age, sex, laterality, BMI, comorbidities, ASA, reason for stent passage, and indwelling time. The stone burden was higher for grades IV and V (p=0.027). Percutaneous nephrolithotomy was the most common procedure (p=0.004) for grades IV and V. The number of procedures until the patients were stone-free was 1.92±1.40, and the hospital stay (4.2±2.5 days), complications (22%), and stone analysis (66% calcium oxalate) were similar between groups. The stone-free rate was lower in grades III to V (60%, 54.5%, and 50%). Conclusions: The endoscopic combined approach in the supine position is a safe and feasible technique that allows removal of retained and encrusted stents in a single procedure. The FECal classification seems to be useful for surgical planning.

ABSTRACT Objectives Measurements of stone features may vary according to the non-contrast computed tomography (NCCT) technique. Using magnified bone window is the most accurate method to measure urinary stones. Possible differences between stone measurements in different NCCT windows have not been evaluated in stones located in the kidney. The aim of this study is to compare measurements of kidney stone features between NCCT bone and soft tissue windows in patients submitted to retrograde intrarenal surgery (RIRS). Materials and Methods Preoperative and 90th postoperative day NCCT were performed in 92 consecutive symptomatic adult patients (115 renal units) with kidney stones between 5 mm to 20 mm (< 15 mm in the lower calyx) treated by RIRS. NCCT were evaluated in the magnified bone window and soft tissue window in three axes in a different time by a single radiologist blinded for the measurements of the NCCT other method. Results Stone largest size (7.92±3.81 vs. 9.13±4.08; mm), volume (435.5±472.7 vs. 683.1±665.0; mm3) and density (989.4±330.2 vs. 893.0±324.6; HU) differed between bone and soft-tissue windows, respectively (p<0.0001) 5.2% of the renal units (6/115) were reclassified from residual fragments > 2 mm on soft tissue window to 0-2 mm on bone window. Conclusion Kidney stone measurements vary according to NCCT window. Measurements in soft tissue window NCCT of stone diameter and volume are larger and stone density is lesser than in bone window. These differences may have impact on clinical decisions.

ABSTRACT Prostate cancer is the second most common cancer and the fifth leading cause of cancer deaths. In Brazil, it is likewise the second most common cancer among men, second only to non-melanoma skin cancers. The aim of this consensus is to align different opinions and interpretations of the medical literature in a practical and patient-oriented approach. The first Brazilian Consensus on the Treatment of Advanced Prostate Cancer was published in 2017, with the goal of reducing the heterogeneity of therapeutic conduct in Brazilian patients with metastatic prostate cancer. We acknowledge that in Brazil the incorporation of different technologies is a big challenge, especially in the Sistema Único de Saúde (SUS), which allows for the disparity in the options available to patients treated in different institutions. In order to update the recommendations and to make them objective and easily accessible, once more a panel of specialists was formed in order to discuss and elaborate a new Brazilian Consensus on Advanced Prostate Cancer. This Consensus was written through a joint initiative of the Brazilian Society of Clinical Oncology (SBOC) and the Brazilian Society of Urology (SBU) to support the clinical decisions of physicians and other health professionals involved in the care of patients with prostate cancer.

RESUMO Objetivo: investigar fatores associados ao uso e à qualidade da Atenção Primária à Saúde, bem como à ocorrência de pneumonia e diarreia em crianças menores de um ano. Método: estudo transversal, realizado com 317 cuidadores de 56 equipes de Saúde da Família de Juazeiro do Norte, Ceará, no período de agosto de 2014 a outubro de 2015, utilizando o instrumento Primary Care Assessment Tool, versão criança. Resultados: no ajuste logístico, criança receber auxílio (OR: 0,54; 0,32-0,91) e acessibilidade à unidade de Atenção Primária à Saúde (OR: 0,49; 0,31-0,76), foram identificadas como possíveis fatores de proteção para episódios de diarreia. As variáveis associadas à pneumonia foram acesso não satisfatório (ORaj: 2,13; IC 95% 1,18-3,82), um provável fator de risco, e coordenação (ORaj: 0,33, IC95% 0,12-0,94), como provável fator de proteção. Conclusão: o atendimento na Atenção Primária resultou em maior chance de não hospitalização por pneumonia, condição considerada sensível aos cuidados nesse modelo de atenção. Complementação da renda familiar e acessibilidade da criança à unidade de saúde apresentaram-se como fatores de proteção para episódios de diarreia. A busca por garantir a presença e extensão dos atributos da Atenção Primária à Saúde possui potencial para modificar positivamente a saúde da criança e, portanto, ambas devem ser asseguradas como direitos dessa população.

ABSTRACT Objective: to investigate factors associated with the use and quality of Primary Health Care, as well as the occurrence of pneumonia and diarrhea in children under one year. Method: cross-sectional study conducted with 317 caregivers of 56 Family Health teams from Juazeiro do Norte, Ceará, from August 2014 to October 2015, using the child version of the Primary Care Assessment Tool, child version. Results: in the logistic adjustment, children received assistance (OR: 0.54; 0.32-0.91) and accessibility to the Primary Health Care Unit (OR: 0.49; 0.31-0.76). identified as possible protective factors for episodes of diarrhea. The variables associated with pneumonia were unsatisfactory access (ORaj: 2.13; 95% CI 1.18-3.82), a likely risk factor, and coordination (ORaj: 0.33, 95% CI 0.12-0,94), as a probable protection factor. Conclusion: primary care attendance resulted in a higher chance of avoiding hospitalization for pneumonia, a condition considered sensitive to care in this care model. Complementing family income and children's accessibility to the health unit were protective factors for episodes of diarrhea. The search to ensure the presence and extension of the Primary Health Care attributes has the potential to positively modify the child's health and, therefore, both should be ensured as rights of this population.

RESUMEN Objetivo: investigar los factores asociados al uso y a la calidad de la Atención Primaria de la Salud, así como la aparición de neumonía y diarrea en niños menores de un año. Método: estudio transversal realizado con 317 cuidadores de 56 equipos de salud familiar de Juazeiro do Norte, Ceará, de agosto de 2014 a octubre de 2015, utilizando la herramienta Primary Care Assessment Tool, versión infantil. Resultados: en el ajuste logístico, los niños recibieron asistencia (OR: 0,54; 0,32-0,91) y accesibilidad a la Unidad de la Atención Primaria de la Salud (OR: 0,49; 0,31-0,76), identificados como posibles factores de protección para los episodios de diarrea. Las variables asociadas con la neumonía fueron el acceso insatisfactorio (ORaj: 2,13; IC 95% 1,18-3,82), un factor de riesgo probable y coordinación (ORaj: 0,33, IC95% 0,12-0,94), como factor probable de protección. Conclusión: la asistencia en la atención primaria resultó en mayor probabilidad de no hospitalización por neumonía, una condición que se considera sensible en los cuidados en este modelo de atención. El complemento de los ingresos familiares y la accesibilidad de los niños a la unidad de salud fueron factores protectores para los episodios de diarrea. La búsqueda para garantizar la presencia y extensión de los atributos de la Atención Primaria de la Salud tiene el potencial de modificar positivamente la salud del niño y, por lo tanto, ambos deben garantizarse como derechos de esta población.

ABSTRACT Objective: to investigate factors associated with the use and quality of Primary Health Care, as well as the occurrence of pneumonia and diarrhea in children under one year. Method: cross-sectional study conducted with 317 caregivers of 56 Family Health teams from Juazeiro do Norte, Ceará, from August 2014 to October 2015, using the child version of the Primary Care Assessment Tool, child version. Results: in the logistic adjustment, children received assistance (OR: 0.54; 0.32-0.91) and accessibility to the Primary Health Care Unit (OR: 0.49; 0.31-0.76). identified as possible protective factors for episodes of diarrhea. The variables associated with pneumonia were unsatisfactory access (ORaj: 2.13; 95% CI 1.18-3.82), a likely risk factor, and coordination (ORaj: 0.33, 95% CI 0.12-0,94), as a probable protection factor. Conclusion: primary care attendance resulted in a higher chance of avoiding hospitalization for pneumonia, a condition considered sensitive to care in this care model. Complementing family income and children's accessibility to the health unit were protective factors for episodes of diarrhea. The search to ensure the presence and extension of the Primary Health Care attributes has the potential to positively modify the child's health and, therefore, both should be ensured as rights of this population.

RESUMEN Objetivo: investigar los factores asociados al uso y a la calidad de la Atención Primaria de la Salud, así como la aparición de neumonía y diarrea en niños menores de un año. Método: estudio transversal realizado con 317 cuidadores de 56 equipos de salud familiar de Juazeiro do Norte, Ceará, de agosto de 2014 a octubre de 2015, utilizando la herramienta Primary Care Assessment Tool, versión infantil. Resultados: en el ajuste logístico, los niños recibieron asistencia (OR: 0,54; 0,32-0,91) y accesibilidad a la Unidad de la Atención Primaria de la Salud (OR: 0,49; 0,31-0,76), identificados como posibles factores de protección para los episodios de diarrea. Las variables asociadas con la neumonía fueron el acceso insatisfactorio (ORaj: 2,13; IC 95% 1,18-3,82), un factor de riesgo probable y coordinación (ORaj: 0,33, IC95% 0,12-0,94), como factor probable de protección. Conclusión: la asistencia en la atención primaria resultó en mayor probabilidad de no hospitalización por neumonía, una condición que se considera sensible en los cuidados en este modelo de atención. El complemento de los ingresos familiares y la accesibilidad de los niños a la unidad de salud fueron factores protectores para los episodios de diarrea. La búsqueda para garantizar la presencia y extensión de los atributos de la Atención Primaria de la Salud tiene el potencial de modificar positivamente la salud del niño y, por lo tanto, ambos deben garantizarse como derechos de esta población.

RESUMO Objetivo: investigar fatores associados ao uso e à qualidade da Atenção Primária à Saúde, bem como à ocorrência de pneumonia e diarreia em crianças menores de um ano. Método: estudo transversal, realizado com 317 cuidadores de 56 equipes de Saúde da Família de Juazeiro do Norte, Ceará, no período de agosto de 2014 a outubro de 2015, utilizando o instrumento Primary Care Assessment Tool, versão criança. Resultados: no ajuste logístico, criança receber auxílio (OR: 0,54; 0,32-0,91) e acessibilidade à unidade de Atenção Primária à Saúde (OR: 0,49; 0,31-0,76), foram identificadas como possíveis fatores de proteção para episódios de diarreia. As variáveis associadas à pneumonia foram acesso não satisfatório (ORaj: 2,13; IC 95% 1,18-3,82), um provável fator de risco, e coordenação (ORaj: 0,33, IC95% 0,12-0,94), como provável fator de proteção. Conclusão: o atendimento na Atenção Primária resultou em maior chance de não hospitalização por pneumonia, condição considerada sensível aos cuidados nesse modelo de atenção. Complementação da renda familiar e acessibilidade da criança à unidade de saúde apresentaram-se como fatores de proteção para episódios de diarreia. A busca por garantir a presença e extensão dos atributos da Atenção Primária à Saúde possui potencial para modificar positivamente a saúde da criança e, portanto, ambas devem ser asseguradas como direitos dessa população.

RESUMO Este trabalho apresenta resultados oriundos de uma pesquisa experimental cujo o objetivo foi analisar o comportamento mecânico de uma mistura betuminosa a frio sob efeitos de cargas estáticas e repetidas. Inicialmente, fez-se uma dosagem Marshall para definição do teor de projeto da mistura, de acordo com a norma DNER (1994a). Após obtenção do teor de projeto, foram moldadas nove amostras para serem submetidas aos seguintes ensaios: módulo de resiliência, resistência à tração por compressão diametral e fadiga. Verificou-se que a estabilidade Marshall, independente do traço utilizado, superou o limite mínimo recomendado na especificação de serviço DNIT (2010a). Quanto à fluência, os valores encontrados superaram os exigidos na referida especificação. Os resultados obtidos para a resistência à tração por compressão diametral média, módulo de resiliência e vida de fadiga da mistura betuminosa foram, respectivamente, de 0,47 MPa, na faixa de 1.530 a 1.837 MPa e menores que 1.000 ciclos (para a maioria das diferenças de tensão aplicadas), os quais foram inferiores àqueles comumente relatados para misturas a quente.

Abstract This paper presents the results of an experimental research aimed at analyzing the mechanical behavior of a cold bituminous mixture under effects of static and repeated loads. Initially, a Marshall mixture design was performed to determine the mixture design contents according to standard DNER (1994a). After obtaining the mixture design contents, nine bituminous specimens were molded and subjected to the following tests: resilient modulus, tensile strength by diametral compression, and fatigue. The Marshall stability, independent from the mixture content used, surpassed the minimum limit recommended by the service specification DNIT (2010a). Regarding the Marshall flow, the values found exceeded the required by the referred specification. The results obtained for the average tensile strength by diametral compression, resilient modulus and fatigue life of the bituminous mixture were, respectively, 0.47 MPa, in the range of 1530-1837 MPa, and lower than 1000 cycles (for most stress differences applied), which were lower than those commonly reported for hot mixtures.

RESUMO 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 estáticas e repetidas. Após a caracterização 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 emulsão. Nesse teor de emulsão, moldaram-se várias amostras, que foram submetidas aos ensaios de módulo de resiliência, resistência à tração por compressão diametral e fadiga. A caracterização dos agregados e do ligante mostrou-se concordante com vários estudos, exceto o resíduo da peneiração, que não atendeu à exigência do IBP (1999). Para os ensaios com as misturas asfálticas, empregaram-se três 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 fluência Marshall de 620 kgf e de 4,20 mm, respectivamente, superaram o limite mínimo recomendado na especificação de serviço do DNIT (2010a). Com relação aos ensaios de módulo de resiliência e de resistência à tração por compressão 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 níveis de tensão aplicados, foi inferior a 1.000 aplicações do carregamento.

ABSTRACT This paper presents the results of an experimental study that aimed to study the mechanical behavior of a cold bituminous mixture under effects of static and repeated loads. After the characterization of the aggregates and the binder employed in the study, it was performed the mixture from the dosage Marshall, obtaining the equivalent project content of 8.5% emulsion. In this emulsion content, several samples were shaped and subjected to the tests of resilient modulus, tensile strength by diametrical compression and fatigue. The characterization of aggregates and binder proved to be consistent with several studies, except the residue of the sifting that did not meet the requirement ofIBP (1999). For tests with the asphalt mixtures, three specimens were employed, each weighing about 1,200 g, compacted with 75 blows on each of their faces. It was observed that the Marshall stability and creep of 620 kgf and 4.20mm, respectively, exceeded the minimum threshold recommended by the service specification DNIT (2010a). With regard to tests of resilience modulus and tensile strength by diametral compression, values of 1,616 MPa and 0.44 MPa were obtained, respectively, verifying that the results were much lower than those found for hot mixtures. The same behavior was observed for the fatigue test that, for most levels of stress applied, was inferior to 1000 applications of loading.

RESUMONeste trabalho, estudou-se a influência do diâmetro e do número de camadas do corpo de prova nas curvas de compactação de laboratório e na resistência mecânica de dois solos residuais de gnaisse da Zona da Mata Norte de Minas Gerais, respectivamente, de texturas argilo-areno-siltosa (Solo 1) e areno-silto-argilosa (Solo 2), com vistas à construção de estradas florestais. Além dos resultados dos ensaios de compactação, determinou-se a resistência à compressão não confinada dos solos empregando corpos de prova compactados na umidade ótima (wot) e nos teores de umidade 3% abaixo e 2% acima, considerando como referência a energia de compactação do ensaio Proctor normal e empregando corpos de prova compactados em uma, duas e três camadas, bem como nos diâmetros de 35 mm, 73 mm e 100 mm, com nove repetições. Para fins práticos de engenharia e com base em análise estatística aplicada aos parâmetros massa específica aparente seca e resistência à compressão não confinada, pode-se concluir que: (i) há diferenças significativas entre as compactações realizadas em uma e em três camadas, não ocorrendo o mesmo nas compactações realizadas em duas e em três camadas, para ambos os solos; e (ii) há diferenças significativas entre a compactação de corpos de prova de diâmetro 100 mm e os demais de 73 mm e 35 mm, para o solo 1 (argiloso), bem como há também diferenças apenas no ramo seco da curva de compactação, para o solo 2 (arenoso).

ABSTRACTThis paper addresses the study of the influence of specimen diameter and number of layers on the laboratory compaction curves and mechanical strength of two gneiss residual soils from Zona da Mata Norte of Minas Gerais state, Brazil, respectively with grain size distributions classified as silty-sandy clay (Soil 1) and clayey-silty sand (Soil 2) for forest road applications. Besides compaction testing data, it was determined the unconfined compression strength of soils using specimens compacted at the optimum water content (wot), wot -3% and wot +2% referred to the standard Proctor compaction effort and using specimens compacted with one, two and three layers as well as diameters of 35 mm, 73 mm and 100 mm, with nine replicates. For practical engineering purpose and based on statistical analysis applied to the parameters dry specific weight and unconfined compression strength it can be concluded that: (i) for both soils, there are significant differences between the compactions carried out in one and three layers, and not the same for two and three layers; and (ii) for Soil 1 (clayey soil), there are significant differences between compaction using 100 mm and the 73 mm and 35 mm diameter specimens, as well as for Soil 2 (sandy soil) these differences occurs only in the dry branch of the compaction curve.

O "grits" é um resíduo sólido de características arenosas e coloração acinzentada, gerado pela indústria de polpa kraft durante a etapa de recuperação do licor branco empregado no cozimento dos cavacos de madeira. O objetivo deste trabalho foi estudar o potencial do grits como material de construção, considerando-se a sua empregabilidade na fabricação de tijolos de solo-cimento. Para a determinação da quantidade ideal de resíduo a ser utilizada, foram estudados os traços em volume 1:14:0; 1:10,5:3,5; 1:7:7; 1:3,5:10,5; e 1:0:14 de cimento, solo e grits, respectivamente. Os materiais foram caracterizados por meio de ensaios de análise granulométrica, limite de liquidez e limite de plasticidade, e os resultados foram de acordo com as prescrições normativas. O ensaio prático da caixa também foi usado para verificar os materiais, e os resultados atenderam às recomendações. Uma vez realizado o ensaio de compactação para obter o teor de umidade ótima, os tijolos foram produzidos com 90% desse valor, pois a resistência à compressão é favorecida com o material do ramo seco. No entanto, durante a moldagem não foi possível produzir tijolos com os traços 1:3,5:10,5 e 1:0:14, pois, nesses casos, as misturas de solo-cimento-grits não apresentaram plasticidade suficiente. Os tijolos produzidos com os demais traços foram, então, submetidos a ensaios de resistência à compressão e de absorção. Em relação à resistência à compressão, aos 28 dias todos os traços apresentaram valores médios superiores ao estabelecido pela normalização, que é de 2,0 MPa. Os tijolos fabricados com maior quantidade de grits apresentaram melhor desempenho no que se refere à resistência mecânica. Assim, este estudo não apenas apresenta o benefício ambiental de destinar corretamente o resíduo, como também contribui com novos materiais para a construção civil.

Grits is a solid residue, with sandy characteristics and grayish appearance, produced by the kraft pulp industry, during the recovery stage of white liquor used in the cooking of the wood chips. The aim of this paper was to study the potential of grits as a building material, considering their employability in the manufacturing of soil-cement blocks. To set the ideal amount of residue to be used, the traits in volume 1:14:0; 1:10,5:3,5; 1:7:7; 1:3,5:10,5; 1:0:14 of cement, soil and grits were studied, respectively. The materials were characterized by the sieve analysis, liquid limit and plastic limit tests and the results are consistent with the prescriptive requirements. The practical test of the box was also used to verify the materials and the results met the recommendations. Once the compaction test was performed to obtain the optimum moisture content, the bricks were produced with 90% of this value, because the compressive strength is increased with dry material. However, it was not possible to produce blocks with traits 1:3,5:10,5 and 1:0:14 because, in these cases, mixtures of soil-cement-grits did not show sufficient plasticity. The blocks produced with others traits were tested for compressive strength and absorption. Regarding the compressive strength at 28 days, all traits had their mean values higher than the normalization, which is 2.0 MPa. The blocks which were produced with higher grits showed better performance in compressive strength. Therefore, this study not only has the environmental benefit of directing the residue properly, but also contributes to new construction materials.

Este artigo aborda a viabilidade técnica do uso de solos locais, preferencialmente os de comportamento geotécnico laterítico, em camadas de reforço do subleito de rodovias vicinais de baixo volume de tráfego, através de ensaios geotécnicos e da classificação MCT (Miniatura, Compactado, Tropical). Para este propósito, consideraram-se amostras deformadas de solos coletadas no subleito das estradas VCS 493 e VCS 296, pertencente à malha rodoviária vicinal do município de Viçosa-MG, Brasil. O programa de estudo de laboratório envolveu a realização dos seguintes ensaios: (i) granulometria conjunta; (ii) limites de Atterberg (LL e LP); (iii) massa específica dos grãos do solo; (iv) compactação e CBR realizados na energia do Proctor normal; (v) compactação Mini-MCV; e (vi) perda de massa do corpo-de-prova por imersão em água. Os resultados desta pesquisa possibilitaram verificar que os solos de comportamento laterítico foram enquadrados no grupo LG' na classificação MCT e que, mesmo apresentando valores de Limite de liquidez e Índice de plasticidade elevados, quando compactados na energia do Proctor normal e, conseqüentemente, imersos em água, não apresentaram expansão com valor significativo no ensaio de CBR. Por outro lado, as areias saprolíticas apresentam perda de massa por imersão (Pi) difícil de ser previsto na Metodologia MCT, pois podem apresentar valores muito elevados e baixos, conforme a compacidade atingida durante o processo de compactação dos corpos-de-prova, como pode ser notado no resultado da amostra 8.

This paper approaches the technical feasibility of using local soils, preferably those of lateritic geotechnical behavior, in subgrade reinforcement layers of low traffic volume vicinal roads through geotechnical testing and MCT methodology (Miniature, Compacted, Tropical). Therefore, disturbed soil samples were collected from the road subgrade VCS 493 and VCS 296 from to the vicinal road net of the city of Viçosa, Minas Gerais state, Brazil. The laboratory study program included the following trials: (i) grain-size distribution; (ii) Atterberg limits (LL and PL); (iii) specific mass of soil grain; (iv) compaction and CBR carried out in normal Proctor energy; (v) mini-MCV compaction; and (vi) specimen weight loss by water immersion. By using the results from this, it was possible to check if soils presenting lateritic behavior were classified in the LG' group of the MCT methodology, and that they even presenting high values of liquid limit and plasticity index, when compacted in normal Proctor energy and therefore water immersed, they did not present expansion with a significant value in CBR trial. On the other hand, the saprolitic sands presented mass loss by water immersion (Pi) difficult to be predicted through the MCT methodology because they can present very high and low values according to compacteness reached during compaction process, as it can be noted in the result from sample 8.

Este artigo aborda a influência da variação da carga por eixo e da pressão de enchimento dos pneus sobre as deflexões superficiais recuperáveis previstas na estrutura de pavimento da estrada não pavimentada VCS 346, considerada representativa da malha vicinal do Município de Viçosa, MG. O programa de estudo considerou as seguintes análises: (i) contagem volumétrica do tráfego, inclusive de veículos comerciais do tipo 2C; (ii) deflexões recuperáveis previstas, em função dos dados disponíveis no estudo; (iii) estrutura do pavimento, com dados referentes ao material das camadas. Com as análises, observou-se que a aplicação de níveis mais críticos de carregamento interferiu significativamente na vida útil do pavimento e, dependendo da combinação da carga por eixo e da pressão de enchimento dos pneus, a vida útil da estrada pode sofrer redução da ordem de 89%. Investigaram-se ainda, neste trabalho, dois métodos para dimensionar a espessura do revestimento primário para rodovias não pavimentadas. Um desses métodos foi o empírico, qual seja, o método do DNIT para dimensionamento de pavimentos flexíveis; e o outro foi fundamentado em teoria elástica para sistemas de camadas. Para o dimensionamento de estradas não pavimentadas melhoradas com uma camada de revestimento primário (sistema de duas camadas), concluiu-se que o procedimento mais adequado foi o emprego da teoria elástica.

This paper approaches the influence of the variation of load per axle and tire pressure on the recoverable superficial deflections in a pavement structure of the VCS 346 unpaved road taken as representative of the secondary road net of Viçosa-MG, Brazil. The program of study considered the following analysis: (i) traffic volume counting including 2C type commercial vehicles; (ii) predicted recoverable superficial deflections in function of the available data from the study; (iii) structure of the pavement including data from the materials of its layers. By the analyses, it was verified that the application of more critical loading levels affected significantly the pavement serviceable life and depending on the combination of axle load and tire pressure, road pavement serviceable life could be reduced by 89%. In this study, it was also investigated the application of two methods to measure sub-grade reinforcement layer thickness of unpaved roads. One of these two methods was empirical, the DNIT's Flexible Pavement Design criteria and the other was based on elastic theory applied to a two layer system. The use of the elastic theory was more adequate to measure unpaved roads improved with wearing courses (two layer system) proved to be the best procedure for designing unpaved road systems.