No description available.

No description available.

The aim of this study was to break through current limits with cement substitutes in concrete paving block and introduce high levels of cementitious constituents. As well as meeting the current strength and durability requirements stated in BS EN 1338:2003 the study reported on the effect of materials variability and leaching properties. The cementitous materials used to replace Portland cement (PC) were Pulverised Fuel Ash (PFA also known as Fly Ash), Ground Granulated Blast Furnace Slag (GGBS), Metakaolin (MK), Silica fume (SF), Glass Powder (GP), Basic Oxygen Slag (BOS) and By Pass Dust (BPD). The first phase of the study analysed 11 groups of ternary cement paste blends using Minitab, a statistical programme to help determine mix designs and optimised mix. Analysis of ternary cement pastes in the first phase concluded that mixes containing GGBS over PFA produced greater strengths at early ages. Mixes confirmed that PC-GGBS-GP provided good strengths due to the SiO2 content within GP providing secondary CSH gel. PC-GGBS-BPD provided good strengths due to SO3 within BPD activating the GGBS through sulphates. The best results in forms of strength were found in PC-GGBS-SF and PC-GGBS-BOS ternary pastes. The fine particles along with the high SiO2 content of SF provided greater pozzolanic reactivity and a greater matrix densification. Fourteen of the best mixes were then taken into the second phase. This is when concrete paving blocks were made from these mixes with the method that was developed at Coventry University. The two mixes with the greatest splitting tensile strength consisted of varying levels of PC-GGBS-SF and were known as the candidate mixes. The durability criteria set out in BS EN 1338:2003 was met, however the minimum strength requirement was not. The candidate mixes were still chosen to be produced in the factory as the manufacturing and curing procedure in the factory was more effective and efficient in comparison to the laboratory procedure. The site trial successfully achieved the minimum requirements for the mechanical properties and durability performance stated in BS EN 1338:2003 and reduced the cement content of concrete paving blocks by 40% wt of PC, with a ternary blend consisting of 60% PC, 25% GGBS and 15%SF. Analysis of material variability was conducted on PFA (regulated commercially available replacement) and BPD (replacement waste material). Results showed that when using regulated commercially available cementitious constituents the chemical composition of the material should be within a given range (For replacement by weight of 10%, 20%, 30%, difference in main oxide should be no greater than 1%, 2.5% and 3.5% respectively) and for the waste material the chemical composition (Limits as stated for regulated commercially available material) as well as fineness (Replacement by weight of 5% and 10% should not have a variability in average particle size of more than 15μm) should be within a range. The two candidate mixes were finally tested for their leaching properties against a leachate that was derived from used oil concentrations. The increase in permeability with the use of GGBS and SF lead to the block absorbing less of the leachate in comparison to the control mix. The study set out to introduce high levels of cementitious constituents in concrete paving blocks. Although it is known that high levels of replacement would cause deterioration, this was done in order for the study to create a database in which the company could refer to and determine which constituents performed well and what the maximum level of replacement could be. The study successfully replaced PC by 40% with 25% GGBS and 15% SF. With blocks actually producing greater strengths than the control mix (100% PC) at 28 days and meeting all the minimum requirements that were set out in BS EN 1338:2003.

Os acostamentos exercem funções importantes em uma rodovia, tanto em relação à melhoria das condições operacionais, tais como a capacidade e a segurança viárias, quanto ao desempenho dos pavimentos, protegendo a estrutura da pista principal, melhorando as condições de drenagem e de transferência de carga. Entretanto, os acostamentos têm sido suprimidos ou implantados de maneira incorreta por razões de economia. O presente trabalho reuniu critérios e recomendações existentes sobre a implantação de acostamentos no que diz respeito à sua influência na capacidade e na segurança viárias, às suas características geométricas, aos métodos para a definição do tipo, dimensionamento e sobre os defeitos encontrados nos pavimentos, tanto nos acostamentos quanto nas pistas. Também efetuou análises para mensurar a importância dos acostamentos no bom desempenho de uma rodovia, tanto em relação às condições operacionais, como do desempenho do pavimento. A partir destas análises verificou-se que a supressão de acostamentos em uma rodovia pode reduzir a sua capacidade em 7% e aumentar o índice de acidentes previstos em até 28%. Com relação ao desempenho dos pavimentos, a partir do levantamento das condições funcionais e estruturais dos pavimentos existentes na malha rodoviária pertencente à Divisão Regional DR-2 do Departamento de Estradas de Rodagem do Estado de São Paulo (DER/SP) efetuado em 2005, verificou-se que o Índice de Qualidade Final da malha composta por rodovias com acostamentos é superior ao da malha composta por rodovias sem acostamentos. Foram então realizadas análises que verificaram a influência dos acostamentos (i) na vida útil de pavimentos flexíveis e rígidos através da utilização do método de dimensionamento da AASHTO; (ii) na espessura das placas de concreto dos pavimentos rígidos através dos métodos de dimensionamento da AASHTO e da PCA; (iii) nas tensões atuantes nas placas de concreto dos pavimentos rígidos através da análise mecanicista com a utilização do programa EVERFE 2.24. Todas as análises mostraram que os acostamentos melhoram significativamente o desempenho do pavimento da pista principal, seja aumentando a sua vida útil de 100 a 400% ou reduzindo a espessura necessária do revestimento da pista principal em cerca de 25%. Realizou-se também uma análise de custo para orientar a definição do tráfego a ser considerado para o dimensionamento do pavimento dos acostamentos, onde se constatou que o valor de 5% do tráfego total considerado para a pista implica em aumento de apenas 2 a 3 % nos custos totais da pavimentação, sendo recomendável o seu uso. Por fim, propôs-se um Fluxograma para Projeto baseado nas análises realizadas e com o objetivo de orientar a decisão de implantar ou não os acostamentos, assim como fornecer recomendações a serem seguidas em ambos os casos. / Shoulders has important functions in a highway, so much in relation to the improvement of the operational conditions, such as the capacity and the road safety, as for the pavements performance, protecting the structure of the mainline, improving the drainage and load transfer conditions. However, the shoulders have been suppressed or implanted in incorrect way for economy reasons. The present work gathered criteria and existent recommendations on the implantation of shoulders related to its influence in the capacity and road safety, to their geometric characteristics, to the methods for the definition of the type, design method and failures in the pavements, in the shoulders and in the tracks. It also made analyses to measure the importance of the shoulders in the good performance of a highway, so much in relation to the operational conditions, as of the pavement performance. Starting from these analyses it was verified that the suppression of shoulders in a highway can reduce its capacity in 7% and to increase the predicted accidents index in up to 28%. Regarding the pavements performance, starting from the functional and structural conditions of the existent pavements in the road mesh belonging to the Regional Division DR-2 of the Department of Highways of the State of São Paulo (DER/SP) in 2005, it was verified that the value of Final Quality Index of the mesh composed by highways with shoulders is superior to the mesh composed by highways without shoulders. Then, analyses were made to verify the influence of the shoulders (i) in the flexible and rigid pavements life cycle through the use of the AASHTO design method; (ii) in the concrete thickness of the rigid pavements through the AASHTO and PCA design methods; (iii) in the stresses in the concrete plate of the rigid pavements through the analysis mechanic with the use of the software EVERFE 2.24. All of the analyses showed that the shoulders improve significantly the pavement performance of the mainline, increasing its life cycle from 100 to 400% or reducing the necessary thickness of the covering of the mainline in about 25%. It also took place a cost analysis to guide the definition of the traffic to be considered in the shoulders pavement design, where it was verified that the value of 5% of the total traffic considered for the mainline increases only 2 to 3% in the total costs of the paving, being advisable its use. Finally, it was proposed a Flowchart for Project based on the accomplished analyses and with the objective of guiding the decision of implanting or not the shoulders, as well as supplying recommendations to be following in both cases.

No description available.

No description available.

A novel strategy was used to assess the risk to health from exposure to polycyclic aromatic hydrocarbons (PAHs), an important class of chemical carcinogens, in workers in the paving and roofing industries using bitumen. The aim was to evaluate the risk of exposure to PAHs at three different stages: these were external exposure "external dose", internal exposure "internal dose" and biological effect "biologically effective dose". The approaches used for quantifying the risk at these stages were ambient monitoring, biological monitoring and biological effect monitoring, respectively. Ambient monitoring was carried out by personal air sampling and measurement of PAH-exposure. Excretion of thioethers (a non-selective biomarker) and 1-hydroxypyrene (a selective biomarker of exposure to pyrene) in urine were determined. Urinary d-glucaric acid, sister chromatid exchange in peripheral blood lymphocytes and micronuclei in exfoliated cells were use for biological effect monitoring. Seven groups of workers were studied. These were office workers, departmental staff and manual workers who were not occupationally exposed to PAHs and who were included as controls, and two groups of payers and roofers who were exposed to bitumen fumes during their work. The ambient monitoring program revealed that concentrations of PAHs in environmental air could be as high as those found in the payers' and roofers' occupational environments. The contribution of these background levels to the external dose of the pa yers and roofers was considerable. Payers and roofers were occupationally exposed to low levels of PAHs. The PAH profile in the personal air sample of the workers was different between the two industries. This was attributed to the presence of PAH-emission sources other than hot bitumen, such as vehicle exhaust. The concentration of naphthalene measured in air samples was a good indicator for identifying the existence of these sources. The quantitative evaluation of the carcinogenic risk inherent in the external dose using the 8 hour TWA concentration as a measuring stick did not seem to be effective due to the low "noise" levels of carcinogenic PAHs present. A semi-quantitative measure of the external exposure was suggested which appeared to be a better reflection of the carcinogenic risk. Urinary thioethers are not sensitive enough to be used as a nonselective biomarker of exposure to low levels of PAHs; however, urinary 1- hydroxypyrene was a good indicator of internal exposure to pyrene and therefore PAHs in bitumen fume. The relationship between 1-hydroxypyrene in urine and specific airborne PAH-exposure indices in the results of the payers, but not the roofers, suggested that the route of exposure in the latter is mainly dermal while that in the payers is more related to respiratory uptake. This observation, however, did not agree with the subjective occupational hygiene assessment where it was observed that the roofers were closer to the source of PAH-emissions due to the nature of their job and both groups did not use any respiratory or personal protective equipment. The measurement of urinary d-glucaric acid excretion suggested, but not strongly, that hepatic enzyme activity was induced in the occupationally PAH-exposed groups in comparison to controls and reflected the internal dose of pyrene or total PAHs. These observation; however, need further investigation. Micronuclei in exfoliated epithelial cells could not be measured in these populations as insufficient bladder epithelial cells were obtained for analysis. Sister chromatid exchange in peripheral blood lymphocytes of payers and roofers was significantly elevated in comparison to control and manual worker group. The group mean frequencies of SCE were significantly correlated with the external exposure to carcinogenic PAHs. This observation suggested that sister chromatid exchange is a very sensitive cytogenetic endpoint and is useful for evaluating the risk of exposure to low levels of carcinogenic PAHs. Risk assessment, such as the one conducted in this study, allows a quantitative estimation of risk associated with long-term exposure to moderate and low levels of airborne exposure to PAHs in bitumen fume. Knowledge of dose response relationship may allow a review of current Occupational Exposure Standards (OES) and Biological Exposure Limits, which are at present either unavailable or based on poor background scientific knowledge for most PAH compounds. In this study we have suggested an Occupational Exposure Limit for PAHs based on the sum of fourteen PAH-species.

Esta dissertação trata do desenvolvimento de um protótipo de Sistema de Gerência de Pavimentos para a rede de aeroportos militares administrados pelo Comando da Aeronáutica (COMAER) e apresenta uma metodologia para a execução da Gerência de Pavimentos no âmbito do COMAER, a fim de subsidiar a elaboração do Plano Plurianual de Obras da Aeronáutica. Para tanto, foram levantadas as informações disponíveis, bem como o inventário de pavimentos das bases aéreas subordinadas ao Quinto Comando Aéreo Regional (V COMAR), o histórico de condição e de intervenção dos pavimentos dos últimos 5 anos, dados de projeto, custos e tráfego aéreo e, a partir desses elementos e de indicações do desempenho dos pavimentos estudados, foi elaborada uma proposta plurianual de investimentos em termos de obras de conservação, a fim de prolongar a vida útil dos mesmos, permitindo um aproveitamento mais racional dos recursos existentes. Além disso, para integrar as informações fragmentadas entre os diversos elos do Sistema de Engenharia espalhados pelo Brasil, foi desenvolvido um Sistema de banco de dados para possibilitar a consulta e cadastramento das avaliações através da INTRAER, a rede interna do Comando da Aeronáutica. / This dissertation concerns in the development of a prototype of a preliminary Pavement Management System for the network of military airports managed by the Brazilian Air Force (COMAER) and aims to provide a methodology for the implementation of the pavement management within the Brazilian Air Force, in order to support the development of the multi-year plan of works. To do it so, the existing information system and the inventory of airfields pavements subject to the Fifth Regional Air Command (COMAR V) was raised, the history of the condition and intervention of decks in the past five years, project data, costs, air traffic and from these elements and performance measures of the pavements studied was an elaborate multi-year investment proposal in terms of conservation works in order to extend the pavement life wich aim at a more rational utilization of resources. In addition, to integrate the fragmented information between the various links of Engineering System throughout Brazil, it was developed a database system to enable to consult and register evaluations through the INTRAER, the internal network of the Brazilian Air Force.

Esta dissertação trata do desenvolvimento de um protótipo de Sistema de Gerência de Pavimentos para a rede de aeroportos militares administrados pelo Comando da Aeronáutica (COMAER) e apresenta uma metodologia para a execução da Gerência de Pavimentos no âmbito do COMAER, a fim de subsidiar a elaboração do Plano Plurianual de Obras da Aeronáutica. Para tanto, foram levantadas as informações disponíveis, bem como o inventário de pavimentos das bases aéreas subordinadas ao Quinto Comando Aéreo Regional (V COMAR), o histórico de condição e de intervenção dos pavimentos dos últimos 5 anos, dados de projeto, custos e tráfego aéreo e, a partir desses elementos e de indicações do desempenho dos pavimentos estudados, foi elaborada uma proposta plurianual de investimentos em termos de obras de conservação, a fim de prolongar a vida útil dos mesmos, permitindo um aproveitamento mais racional dos recursos existentes. Além disso, para integrar as informações fragmentadas entre os diversos elos do Sistema de Engenharia espalhados pelo Brasil, foi desenvolvido um Sistema de banco de dados para possibilitar a consulta e cadastramento das avaliações através da INTRAER, a rede interna do Comando da Aeronáutica. / This dissertation concerns in the development of a prototype of a preliminary Pavement Management System for the network of military airports managed by the Brazilian Air Force (COMAER) and aims to provide a methodology for the implementation of the pavement management within the Brazilian Air Force, in order to support the development of the multi-year plan of works. To do it so, the existing information system and the inventory of airfields pavements subject to the Fifth Regional Air Command (COMAR V) was raised, the history of the condition and intervention of decks in the past five years, project data, costs, air traffic and from these elements and performance measures of the pavements studied was an elaborate multi-year investment proposal in terms of conservation works in order to extend the pavement life wich aim at a more rational utilization of resources. In addition, to integrate the fragmented information between the various links of Engineering System throughout Brazil, it was developed a database system to enable to consult and register evaluations through the INTRAER, the internal network of the Brazilian Air Force.

Esta dissertação trata do desenvolvimento de um protótipo de Sistema de Gerência de Pavimentos para a rede de aeroportos militares administrados pelo Comando da Aeronáutica (COMAER) e apresenta uma metodologia para a execução da Gerência de Pavimentos no âmbito do COMAER, a fim de subsidiar a elaboração do Plano Plurianual de Obras da Aeronáutica. Para tanto, foram levantadas as informações disponíveis, bem como o inventário de pavimentos das bases aéreas subordinadas ao Quinto Comando Aéreo Regional (V COMAR), o histórico de condição e de intervenção dos pavimentos dos últimos 5 anos, dados de projeto, custos e tráfego aéreo e, a partir desses elementos e de indicações do desempenho dos pavimentos estudados, foi elaborada uma proposta plurianual de investimentos em termos de obras de conservação, a fim de prolongar a vida útil dos mesmos, permitindo um aproveitamento mais racional dos recursos existentes. Além disso, para integrar as informações fragmentadas entre os diversos elos do Sistema de Engenharia espalhados pelo Brasil, foi desenvolvido um Sistema de banco de dados para possibilitar a consulta e cadastramento das avaliações através da INTRAER, a rede interna do Comando da Aeronáutica. / This dissertation concerns in the development of a prototype of a preliminary Pavement Management System for the network of military airports managed by the Brazilian Air Force (COMAER) and aims to provide a methodology for the implementation of the pavement management within the Brazilian Air Force, in order to support the development of the multi-year plan of works. To do it so, the existing information system and the inventory of airfields pavements subject to the Fifth Regional Air Command (COMAR V) was raised, the history of the condition and intervention of decks in the past five years, project data, costs, air traffic and from these elements and performance measures of the pavements studied was an elaborate multi-year investment proposal in terms of conservation works in order to extend the pavement life wich aim at a more rational utilization of resources. In addition, to integrate the fragmented information between the various links of Engineering System throughout Brazil, it was developed a database system to enable to consult and register evaluations through the INTRAER, the internal network of the Brazilian Air Force.