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<p>Lifetime Engineering (or Life Cycle Engineering) is a technical approach for meeting the current objective of sustainable development. The approach is aimed to turn today’s reactive and short-term design, management and maintenance planning towards an optimised and long-term technical approach. The life cycle based management and maintenance planning approach includes condition assessment, predictive modelling of performance changes, maintenance, repair and refurbishment planning and decisions. The Life Cycle Management System (LMS) is a predictive and generic life cycle based management system aimed to support all types of decision making and planning of optimal maintenance, repair and refurbishment activities of any constructed works. The system takes into account a number of aspects in sustainable and conscious development such as human requirements, life cycle economy, life cycle ecology and cultural requirements. The LMS is a system by which the complete system or parts thereof, works in co-operation or as a complement to existing business support systems. The system is module based where each module represents a subprocess within the maintenance management process. The scope of this thesis is focused on development and adaptation of the predictive characteristic of LMS towards a presumptive user. The objective is to develop and adapt a Service Life Performance Analysis module applicable for condition based Facility Management System in general and for condition based Bridge Management System in particular. Emphasis is placed on development and adaptation of a conditional probability based Service Life Performance Analysis model in which degradation models and Markov chains play a decisive role. The thesis deals also with development and adaptation of environmental exposure data recording and processing, with special emphasis on quantitative environmental classification in order to provide a simplified method of Service Life Performance Analysis.</p>

Aluminized steel pipes are expected to have a long service life, e.g. 75 years. Spiral ribbed aluminized pipes (SRAP) have been widely specified and used by the Florida Department of Transportation (FDOT) for drainage of runoff water. Confidence in the long term durability of SRAP has been challenged by recent unexpected early corrosion failures in various Florida locations. SRAP premature corrosion incidents have occurred in two modalities. Mode A has taken place in near-neutral soil environments and has often been associated with either gross manufacturing defects (i.e. helical cuts) or corrosion concentration at or near the ribs. Mode B took place in pipes in contact with limestone backfill and corrosion damage was in the form of perforations, not preferentially located at the ribs, and not necessarily associated with other deficiencies. These failures motivated this research. The objectives of this work are to establish to what extent the Mode A corrosion incidents can be ascribed to manufacturing defects, that can be rectified by appropriate quality control, as opposed to an intrinsic vulnerability to corrosion of regularly produced SRAP due to ordinary forming strains and to determine the mechanism responsible for Mode B corrosion including the role that limestone backfill played in that deterioration. To achieve those objectives, laboratory experiments were conducted to replicate the conditions for Mode A and Mode B. Overall, the findings of this and previous work suggest that much of the corrosion damage observed in the Mode A incidents were promoted more by manufacturing deficiencies and less by any possible inherent susceptibility of corrosion at the ribs of SRAP that was produced following appropriate quality control. Experiments to explore the causes of Mode B corrosion showed that high pH values, sufficient to cause dissolution of the passive film on aluminum, can develop under exposure of limestone to flowing natural water. The findings substantiate, for the first time, an important vulnerability of aluminized steel in limestone soils and provide an explanation for the rapid onset deterioration observed at the field under Mode B. The findings also provide strong evidence in support of service guidelines to disallow the use of limestone bedding for aluminized steel pipe, including SRAP.

The ageing of high density polyethylene geomembrane (GM) liners used to minimize advection and diffusion of contaminants in municipal solid waste landfill leachate and in hydrocarbon spills to the environment is examined. The evaluation of the ageing of GMs used in landfills involved four components. First, a laboratory-accelerated ageing investigation of a GM exposed to air, water and leachate at elevated temperatures. Service life of a GM (Stage I: Antioxidant depletion, Stage II: Induction, and Stage III: Polymer degradation) is examined. The results demonstrate the critical role of antioxidants in protecting against oxidative degradation. The service life of the GM is predicted. Second, a study was conducted to provide an estimate of Stage I for a GM in a composite liner. The results indicated that immersion tests are too severe and the service life is substantially greater for a GM in composite liner than implied by leachate immersion tests. Third, a comparison of ageing with three different “protection” layers between the GM and overlying gravel and leachate is reported. A slower antioxidant depletion rate is observed when geotextile-geosynthetic clay liner and geotextile-sand-geotextile are applied than with a typical geotextile alone. This could be partially attributed to the attenuation of leachate constituents by the protection layer as well as the buildup of antioxidant concentration on either side of GM thereby reducing the concentration gradient and outward diffusive flux of antioxidants. Fourth, diffusion modelling is used to evaluate the results from immersion and composite liner simulation tests. Diffusion modelling provided a means for predicting the performance of the GMs in conditions other than the typical test conditions. The evaluation of the ageing of GM used in barrier system for hydrocarbon involved two components. First, untreated and fluorinated GMs immersed in jet fuel were tested. Results show that antioxidants depleted at slower rate from fluorinated GM than untreated GM. This suggested a significant beneficial effect of fluorination. Antioxidant depletion time is predicted at field temperatures. Second, the time dependant change in GM samples used at jet fuel containment site constructed in 2001 is reported. The GM is shown to be performing very well. / Thesis (Ph.D, Civil Engineering) -- Queen's University, 2009-01-14 10:46:31.089

The KENTRACK program is a finite element based railway trackbed structural design program that can be utilized to analyze trackbeds having various combinations of all-granular and asphalt-bound layered support. It is applicable for calculating compressive stresses at the top of subgrade, indicative of potential long-term trackbed settlement failure. Furthermore, for trackbeds containing asphalt layer, it is applicable for calculating tensile strains at the bottom of the asphalt layer, indicative of potential fatigue cracking. The program was recently expanded to include both English and international units. A procedure has been incorporated to provide a path to save results in a text formation in post-Windows XP operating systems. More importantly, properties of performance graded (PG) asphalt binders and the Witczak E* predictive model have been incorporated in the 4.0 Version of the program. Component layers of typical trackbed support systems are analyzed while predicting the significance of layer thicknesses and material properties on design and performance. The effect of various material parameters and loading magnitudes on trackbed design and evaluation, as determined and predicted by the computer program, are presented. Variances in subgrade modulus and axle loads and the incorporation of a layer of asphalt within the track structure have significant effects on subgrade vertical compressive stresses and predicted trackbed service lives. The parameter assessments are presented and evaluated using sensitivity analysis. Recommendations for future research are suggested.

Mémoire (M.Eng.)--Université du Québec à Chicoutimi, 1995. / Document électronique également accessible en format PDF. CaQCU

Thesis (doctoral)--Helsinki University of Technology, 1999. / Includes bibliographical references. Also available on the World Wide Web.

Devido à preocupação com a durabilidade das estruturas de concreto armado surgiram novas linhas de pesquisa destacando-se, dentre elas, a previsão de vida útil. Estes estudos deram origem a diversos modelos que tentam estabelecer o comportamento do concreto quando exposto a ambientes agressivos durante um determinado período. Existem várias maneiras de se modelar este comportamento: com base em resultados obtidos em experiências anteriores; a partir de ensaios de degradação acelerados; por métodos determinísticos e probabilísticos ou estocásticos. A estimativa de vida útil das estruturas de concreto empregando dados de ensaios acelerados é recomendada pela ASTM E-632 (1996) desde que estes sejam correlacionados com resultados de ensaios não acelerados ou naturais. A correlação entre estes ensaios possibilita a determinação dos coeficientes de aceleração, os quais expressam o número de vezes em que o ensaio acelerado representa o fenômeno de degradação natural. Dentro deste contexto o presente trabalho avalia a carbonatação do concreto com e sem adição de sílica ativa exposto a degradação natural e acelerada, verificando também a influência do teor desta adição e da relação água/aglomerante na carbonatação. Em paralelo foram determinados os coeficientes de carbonatação (kc) e de aceleração (αa). Os concretos estudados possuem relação água/aglomerante de 0,30; 0,35; 0,45; 0,60 e 0,80 e teor de adição de 0; 5; 10; 15e 20%. A carbonatação natural das amostras foi avaliada após 7 anos de exposição ao CO2, tendo como ambiente de degradação a cidade de Porto Alegre, RS. Os dados de carbonatação acelerada foram obtidos aos 7, 28, 63 e 98 dias de exposição ao CO2 com concentração de 5%, temperatura de 25°C e umidade relativa (UR) de 70%. Para o ensaio acelerado, baseado em análise estatística por meio de regressão múltipla não-linear, os resultados apontaram que a adição de sílica ativa em dosagens com relação água/aglomerante elevada aumenta a profundidade de carbonatação do concreto. Para a relação água/aglomerante de 0,80 com 0 e 20% de adição de sílica ativa, os coeficientes de aceleração obtidos foram de 31,15 e 35,49, respectivamente. / New researches has been appeared with the concern of reinforced concrete structures durability, standing out the service life prediction. These studies creates some models that establish the concrete performance when exposed to an aggressive environment. There are several ways to modeling this performance: with results obtained in previous tests; with accelerated degradation tests; or deterministic and stochastic methods. The concrete structures service life prediction using short term test data are recommended by ASTM E-632 (1996) since these are correlated with long term test results. The correlation among these tests makes possible the acceleration coefficient determination, which express how the accelerated tests represents the natural degradation phenomenon. In this sense, this work evaluate the concrete carbonation with and without silica fume exposed to natural and accelerated test, verifying the influence of silica fume tenor in this material and water – binder ratio in the carbonation. In addition to this, were determined the carbonation (kc) and acceleration coefficients (αa). The concretes studied has a 0,30; 0,35; 0,45; 0,60 and 0,80 water-binder ratio and 0; 5; 10; 15 and 20% addition tenor. The samples natural carbonation was analyzed after 7 years of CO2 exhibition from Porto Alegre city environment degradation. The accelerated carbonation data were obtained in 7, 28, 63 and 98 days of CO2 exhibition with 5% concentration, temperature of 20°C and humidity of 60%. In accelerated tests, based on statistical analysis through nonlinear estimation multiple regression, the results showed that the silica fume addition in high water-binder ratio mixtures increases the concrete carbonation depth. For water-binder ratio 0,80 with silica fume addition of 0 and 20%, the acceleration coefficients obtained were 31,15 and 35,49, respectively.

Devido à preocupação com a durabilidade das estruturas de concreto armado surgiram novas linhas de pesquisa destacando-se, dentre elas, a previsão de vida útil. Estes estudos deram origem a diversos modelos que tentam estabelecer o comportamento do concreto quando exposto a ambientes agressivos durante um determinado período. Existem várias maneiras de se modelar este comportamento: com base em resultados obtidos em experiências anteriores; a partir de ensaios de degradação acelerados; por métodos determinísticos e probabilísticos ou estocásticos. A estimativa de vida útil das estruturas de concreto empregando dados de ensaios acelerados é recomendada pela ASTM E-632 (1996) desde que estes sejam correlacionados com resultados de ensaios não acelerados ou naturais. A correlação entre estes ensaios possibilita a determinação dos coeficientes de aceleração, os quais expressam o número de vezes em que o ensaio acelerado representa o fenômeno de degradação natural. Dentro deste contexto o presente trabalho avalia a carbonatação do concreto com e sem adição de sílica ativa exposto a degradação natural e acelerada, verificando também a influência do teor desta adição e da relação água/aglomerante na carbonatação. Em paralelo foram determinados os coeficientes de carbonatação (kc) e de aceleração (αa). Os concretos estudados possuem relação água/aglomerante de 0,30; 0,35; 0,45; 0,60 e 0,80 e teor de adição de 0; 5; 10; 15e 20%. A carbonatação natural das amostras foi avaliada após 7 anos de exposição ao CO2, tendo como ambiente de degradação a cidade de Porto Alegre, RS. Os dados de carbonatação acelerada foram obtidos aos 7, 28, 63 e 98 dias de exposição ao CO2 com concentração de 5%, temperatura de 25°C e umidade relativa (UR) de 70%. Para o ensaio acelerado, baseado em análise estatística por meio de regressão múltipla não-linear, os resultados apontaram que a adição de sílica ativa em dosagens com relação água/aglomerante elevada aumenta a profundidade de carbonatação do concreto. Para a relação água/aglomerante de 0,80 com 0 e 20% de adição de sílica ativa, os coeficientes de aceleração obtidos foram de 31,15 e 35,49, respectivamente. / New researches has been appeared with the concern of reinforced concrete structures durability, standing out the service life prediction. These studies creates some models that establish the concrete performance when exposed to an aggressive environment. There are several ways to modeling this performance: with results obtained in previous tests; with accelerated degradation tests; or deterministic and stochastic methods. The concrete structures service life prediction using short term test data are recommended by ASTM E-632 (1996) since these are correlated with long term test results. The correlation among these tests makes possible the acceleration coefficient determination, which express how the accelerated tests represents the natural degradation phenomenon. In this sense, this work evaluate the concrete carbonation with and without silica fume exposed to natural and accelerated test, verifying the influence of silica fume tenor in this material and water – binder ratio in the carbonation. In addition to this, were determined the carbonation (kc) and acceleration coefficients (αa). The concretes studied has a 0,30; 0,35; 0,45; 0,60 and 0,80 water-binder ratio and 0; 5; 10; 15 and 20% addition tenor. The samples natural carbonation was analyzed after 7 years of CO2 exhibition from Porto Alegre city environment degradation. The accelerated carbonation data were obtained in 7, 28, 63 and 98 days of CO2 exhibition with 5% concentration, temperature of 20°C and humidity of 60%. In accelerated tests, based on statistical analysis through nonlinear estimation multiple regression, the results showed that the silica fume addition in high water-binder ratio mixtures increases the concrete carbonation depth. For water-binder ratio 0,80 with silica fume addition of 0 and 20%, the acceleration coefficients obtained were 31,15 and 35,49, respectively.

Devido à preocupação com a durabilidade das estruturas de concreto armado surgiram novas linhas de pesquisa destacando-se, dentre elas, a previsão de vida útil. Estes estudos deram origem a diversos modelos que tentam estabelecer o comportamento do concreto quando exposto a ambientes agressivos durante um determinado período. Existem várias maneiras de se modelar este comportamento: com base em resultados obtidos em experiências anteriores; a partir de ensaios de degradação acelerados; por métodos determinísticos e probabilísticos ou estocásticos. A estimativa de vida útil das estruturas de concreto empregando dados de ensaios acelerados é recomendada pela ASTM E-632 (1996) desde que estes sejam correlacionados com resultados de ensaios não acelerados ou naturais. A correlação entre estes ensaios possibilita a determinação dos coeficientes de aceleração, os quais expressam o número de vezes em que o ensaio acelerado representa o fenômeno de degradação natural. Dentro deste contexto o presente trabalho avalia a carbonatação do concreto com e sem adição de sílica ativa exposto a degradação natural e acelerada, verificando também a influência do teor desta adição e da relação água/aglomerante na carbonatação. Em paralelo foram determinados os coeficientes de carbonatação (kc) e de aceleração (αa). Os concretos estudados possuem relação água/aglomerante de 0,30; 0,35; 0,45; 0,60 e 0,80 e teor de adição de 0; 5; 10; 15e 20%. A carbonatação natural das amostras foi avaliada após 7 anos de exposição ao CO2, tendo como ambiente de degradação a cidade de Porto Alegre, RS. Os dados de carbonatação acelerada foram obtidos aos 7, 28, 63 e 98 dias de exposição ao CO2 com concentração de 5%, temperatura de 25°C e umidade relativa (UR) de 70%. Para o ensaio acelerado, baseado em análise estatística por meio de regressão múltipla não-linear, os resultados apontaram que a adição de sílica ativa em dosagens com relação água/aglomerante elevada aumenta a profundidade de carbonatação do concreto. Para a relação água/aglomerante de 0,80 com 0 e 20% de adição de sílica ativa, os coeficientes de aceleração obtidos foram de 31,15 e 35,49, respectivamente. / New researches has been appeared with the concern of reinforced concrete structures durability, standing out the service life prediction. These studies creates some models that establish the concrete performance when exposed to an aggressive environment. There are several ways to modeling this performance: with results obtained in previous tests; with accelerated degradation tests; or deterministic and stochastic methods. The concrete structures service life prediction using short term test data are recommended by ASTM E-632 (1996) since these are correlated with long term test results. The correlation among these tests makes possible the acceleration coefficient determination, which express how the accelerated tests represents the natural degradation phenomenon. In this sense, this work evaluate the concrete carbonation with and without silica fume exposed to natural and accelerated test, verifying the influence of silica fume tenor in this material and water – binder ratio in the carbonation. In addition to this, were determined the carbonation (kc) and acceleration coefficients (αa). The concretes studied has a 0,30; 0,35; 0,45; 0,60 and 0,80 water-binder ratio and 0; 5; 10; 15 and 20% addition tenor. The samples natural carbonation was analyzed after 7 years of CO2 exhibition from Porto Alegre city environment degradation. The accelerated carbonation data were obtained in 7, 28, 63 and 98 days of CO2 exhibition with 5% concentration, temperature of 20°C and humidity of 60%. In accelerated tests, based on statistical analysis through nonlinear estimation multiple regression, the results showed that the silica fume addition in high water-binder ratio mixtures increases the concrete carbonation depth. For water-binder ratio 0,80 with silica fume addition of 0 and 20%, the acceleration coefficients obtained were 31,15 and 35,49, respectively.