A crescente quantidade de resíduos sólidos da construção civil gerada em cidades de médio e grande portes tem sido fonte de preocupação em todo o mundo em função de questões ambientais, econômicas e até sociais. Desta forma, a reciclagem dos resíduos de construção para a produção de agregados torna-se uma alternativa interessante, principalmente em função de normas e pesquisas já existentes que podem garantir sua aplicação. A pavimentação com agregados reciclados já vem sendo amplamente realizada em alguns países onde, inclusive, já existe conhecimento consolidado sobre o assunto. No Brasil, as primeiras experiências que remetem ao uso de agregados reciclados em pavimentação datam de meados da década de 80. Desde então, poucas pesquisas sobre o tema vem sendo realizadas, embora haja a necessidade de se procurar novas técnicas e materiais no setor de infra-estrutura rodoviária, uma vez que o país possui somente cerca de 10% de suas vias, muitas vezes urbanas, em condição pavimentada. Este trabalho analisa laboratorialmente aspectos físicos e de comportamento mecânico do agregado reciclado da cidade de São Paulo, a ser utilizado em camadas de base, sub-base ou reforço do subleito de pavimento, em substituição aos materiais convencionais, com enfoque em vias urbanas de baixo volume de tráfego. O estudo envolveu a análise do agregado reciclado in natura, além de sua mistura com 4% de cal ou 4% de cimento Portland, como forma de promover um aumento da resistência do material. Além disso, foram realizados alguns ensaios com brita graduada (material comumente empregado em pavimentos), a fim de comparar resultados. Concluiu-se que o agregado reciclado analisado é de uso promissor em pavimentação, dadas suas propriedades físicas e mecânicas satisfatórias, comparáveis a tradicionais materiais estabilizados granulometricamente ou mesmo a brita graduada simples. Ademais, a adição de cal ou cimento Portland apresenta-se como excelente alternativa quanto ao requisito de aumento de resistência do material reciclado. / The increasing amount of construction and demolition waste generated in medium-sized and large cities has become a source of concern all over the world due to environmental, economic and even social issues. Thus, the recycling of construction and demolition waste to produce aggregates becomes an interesting alternative mainly because of existing specifications and researches that can guarantee its application. Paving with recycled aggregates has already been largely done in some countries where there is even a consolidated knowledge about the subject. In Brazil, preliminary experiences that refer to the use of recycled aggregates in pavement layers date from the mid 80s. Since then, few researches on the subject have been conducted, although it is necessary to look for new techniques and materials in the road infra-structure sector, since the country has only about 10% of its roads, many times urban ones, in paved condition. This work analyses recycled aggregates from São Paulo City as a material to be used in base, subbase or subgrade reinforcement courses in urban roads of low-volume traffic, to replace conventional materials. So, physical and mechanical behaviour aspects of the material were observed by means of laboratory tests. This study involved the analysis of recycled aggregate in natura, as well as its mix with 4% of lime or 4% of Portland cement, to promote a gain in strength. Moreover, some tests were made using graded crushed rock (that is commonly used as a pavement material) so as to compare the results. It was concluded that recycled aggregate is promising for paving, given its satisfactory physical and mechanical properties, comparable to traditional granulometrically stabilized materials or even to simple graded crushed rock. The addition of lime or Portland cement is an excellent alternative concerning the increase in strength of those recycled materials.

Os solos das regiões arrozeiras apresentam características geotécnicas inadequadas para uso como revestimentos primários de estradas. Isto força o transporte de materiais de jazidas distantes, o que, além de onerar o custo de construção, nem sempre é uma solução durável. Nesta tese relata-se uma pesquisa que apresenta uma solução para esse problema: a pavimentação de estradas de baixo volume de tráfego com solo local modificado com cal. Foram realizados estudos laboratoriais e de campo, e os resultados analisados através de uma abordagem mecanístico-empírica. Dois pavimentos experimentais com revestimentos de solo-cal foram construídos e monitorados próximo a Cebollatí, leste do Uruguai. Foram realizados ensaios de caracterização e comportamento mecânico do solo e de misturas de solo e cal, variando-se o teor de cal, o tempo de cura e a energia de compactação. Realizaram-se ensaios de módulo de resiliência, para o qual foi projetado, montado e operado o primeiro equipamento de ensaios de carga repetida na compressão triaxial do Uruguai. Também foram realizados ensaios de fadiga na compressão diametral para o solo modificado com 3% e 5% de cal, curado por 28 e 150 dias. Para entender o comportamento das camadas de solo modificado com cal submetidas ao tráfego, realizou-se uma análise conjunta dos resultados laboratoriais e do monitoramento dos trechos experimentais, com uso de modelos computacionais. Apesar das limitações construtivas, de terem sido liberados ao tráfego em plena safra e das más condições de drenagem da região, após 5 anos de trafego, os pavimentos não mostram trincas de fadiga ou afundamentos nas trilhas de roda. Assim, a pavimentação de estradas de baixo volume de tráfego em regiões arrozeiras com revestimentos de solo local modificado com cal provou ser uma alternativa economicamente vantajosa, por reduzir custos de construção e manutenção, e sustentável, por preservar materiais não-renováveis, como solos e rochas. / Soils in rice plantation areas generally present geotechnical characteristics unsuitable for use as primary wearing course of roads. Because of that, it is necessary to import materials from distant sites, a solution that, besides increasing construction cost, is rarely long-lasting. In this thesis a research on paving low volume roads with lime modified local soils is reported, in order to present an alternative solution to that problem. Both laboratory and field studies were carried out and the results were analyzed by means of a mechanistic-empirical approach. Two test sections with wearing courses made of lime modified soil were built and monitored close to Cebollatí, a village in the east of Uruguay. Previously, laboratory characterization and mechanical tests on samples of the sedimentary soil were carried out. Lime contents for mixtures were determined and the stress-strain-strength behavior of mixes with different levels of lime content, curing time and compaction energy was studied. In order to analyze the elastic behavior of the lime modified soil under traffic, resilient modulus tests were carried out. This motivated the design, assembly and use of the first equipment for triaxial compression repeated loading tests in Uruguay. Besides, stress controlled fatigue tests were performed on cylindrical specimens of soil modified with 3% and 5% of lime, cured for 28 and 150 days. The results of laboratory tests and field monitoring were analyzed using computational models. In spite of the difficulties faced during pavements construction, including heavy traffic in early days, and the poor drainage, after 5 years of service no cracks or ruts are seen on top of the test pavements. Therefore, paving low volume roads in rice plantation areas with lime modified wearing courses has proved to be a cost-effective alternative, reducing construction and maintenance costs, and a sustainable practice, preserving non-renewable materials such as rocks and soils.

Os solos das regiões arrozeiras apresentam características geotécnicas inadequadas para uso como revestimentos primários de estradas. Isto força o transporte de materiais de jazidas distantes, o que, além de onerar o custo de construção, nem sempre é uma solução durável. Nesta tese relata-se uma pesquisa que apresenta uma solução para esse problema: a pavimentação de estradas de baixo volume de tráfego com solo local modificado com cal. Foram realizados estudos laboratoriais e de campo, e os resultados analisados através de uma abordagem mecanístico-empírica. Dois pavimentos experimentais com revestimentos de solo-cal foram construídos e monitorados próximo a Cebollatí, leste do Uruguai. Foram realizados ensaios de caracterização e comportamento mecânico do solo e de misturas de solo e cal, variando-se o teor de cal, o tempo de cura e a energia de compactação. Realizaram-se ensaios de módulo de resiliência, para o qual foi projetado, montado e operado o primeiro equipamento de ensaios de carga repetida na compressão triaxial do Uruguai. Também foram realizados ensaios de fadiga na compressão diametral para o solo modificado com 3% e 5% de cal, curado por 28 e 150 dias. Para entender o comportamento das camadas de solo modificado com cal submetidas ao tráfego, realizou-se uma análise conjunta dos resultados laboratoriais e do monitoramento dos trechos experimentais, com uso de modelos computacionais. Apesar das limitações construtivas, de terem sido liberados ao tráfego em plena safra e das más condições de drenagem da região, após 5 anos de trafego, os pavimentos não mostram trincas de fadiga ou afundamentos nas trilhas de roda. Assim, a pavimentação de estradas de baixo volume de tráfego em regiões arrozeiras com revestimentos de solo local modificado com cal provou ser uma alternativa economicamente vantajosa, por reduzir custos de construção e manutenção, e sustentável, por preservar materiais não-renováveis, como solos e rochas. / Soils in rice plantation areas generally present geotechnical characteristics unsuitable for use as primary wearing course of roads. Because of that, it is necessary to import materials from distant sites, a solution that, besides increasing construction cost, is rarely long-lasting. In this thesis a research on paving low volume roads with lime modified local soils is reported, in order to present an alternative solution to that problem. Both laboratory and field studies were carried out and the results were analyzed by means of a mechanistic-empirical approach. Two test sections with wearing courses made of lime modified soil were built and monitored close to Cebollatí, a village in the east of Uruguay. Previously, laboratory characterization and mechanical tests on samples of the sedimentary soil were carried out. Lime contents for mixtures were determined and the stress-strain-strength behavior of mixes with different levels of lime content, curing time and compaction energy was studied. In order to analyze the elastic behavior of the lime modified soil under traffic, resilient modulus tests were carried out. This motivated the design, assembly and use of the first equipment for triaxial compression repeated loading tests in Uruguay. Besides, stress controlled fatigue tests were performed on cylindrical specimens of soil modified with 3% and 5% of lime, cured for 28 and 150 days. The results of laboratory tests and field monitoring were analyzed using computational models. In spite of the difficulties faced during pavements construction, including heavy traffic in early days, and the poor drainage, after 5 years of service no cracks or ruts are seen on top of the test pavements. Therefore, paving low volume roads in rice plantation areas with lime modified wearing courses has proved to be a cost-effective alternative, reducing construction and maintenance costs, and a sustainable practice, preserving non-renewable materials such as rocks and soils.

IC設計公司的間接成本高，須追求規模經濟，但對物聯網這種少量多樣的應用又有厚望。因此多會謹慎投入，怕投入如流水，又怕咬不到餅。 面對整體龐大的物聯網產業，歐美大廠運用優勢，嘗試建立特有的生態圈將各方納入。案例IC設計公司的規模很難和歐美大廠對作，但也有其優勢，不過原規模經濟的商業模式不再適用。 IC複雜使其位居重要位置，而案例IC設計公司擁有許多優秀工程人才，再加上成熟產品線廣，且和物聯網關聯，都是優勢資源。但做的是B2B生意，接觸不到終端市場，而新IC開發時間長，導致對終端需求掌握度低，且現有工程師數量是無法支援有多樣需求的微型物聯網業者，這些就是劣勢資源。 如案例IC設計公司將微型物聯網業者及獨立工作者拉到平台上，提供工作者自主工作機會，同時滿足物聯網業者不足的支援人力。案例IC設計公司須貢獻包含工作者的訓練與認證、協助物聯網業者找到符合的工作者、設計專案流程管理機制同時確保工作者收得到價金。如此解決了對微型物聯網業者支援不夠的問題，還可藉由平台獲取最真確的需求資訊，又解決另一困境。 三方都有得且無太多風險，可行性確認。用波特的五力分析，案例IC設計公司導入新商業模式有相當優勢，早投入更可建立先行者優勢。

Geometrical variation is an unavoidable aspect in all types of manufacturing that may, unless managed, risk failure in fulfilling product requirements which may result in rework, delays and bad publicity. The term geometry assurance includes the tools, methods and processes that can be utilized to manage the effects of geometrical variation and to ensure fulfillment of esthetical, functional and assembly requirements. While state of the art research in geometry assurance is extensively applied within the automotive and aerospace industries with great success, its application in low volume manufacturing of complex products remains limited. The shipbuilding industry is an example of such an industry, often manufacturing large and complex products in low quantities. Further, the shipbuilding industry has historically been labor-intensive and relied on craftsmanship throughout the product realization process. However, studies indicate that a technology-intensive development is crucial for companies in order to maintain market competitiveness. This transition places high demands on a well-established geometry assurance process in order to ensure successful assembly and fulfillment of product requirements.  In this thesis, a feasibility study is conducted on how geometry assurance may be applied in low volume manufacturing of complex products. By developing guidelines on how geometry assurance may be applied, the purpose is to improve geometrical quality throughout the product realization process and to reduce lead times, costs and increase assembly precision.  To explore the feasibility of geometry assurance in low volume manufacturing of complex products, a work structure consisting of three phases was established. In the first phase, a current state analysis of the collaboration partner Saab Kockums was conducted parallel to studying state of the art research in geometry assurance. In phase two, the state of practice of companies in the automotive and aerospace industries was studied in order to determine how they apply state of the art research. By interviewing industry specialists and combining gained knowledge from the first two phases, guidelines on how geometry assurance may be applied in low volume manufacturing of complex products was developed. In phase three, based on these guidelines, suggestions on how the geometry assurance process in pipe manufacturing at Saab Kockums can be improved was developed. The results of this study indicate that geometry assurance is applicable in low volume manufacturing of complex products. However, alternative methods may be required. Based on gained knowledge and insights from interviews with industry specialists, guidelines on how geometry assurance in low volume manufacturing of complex products may be applied are proposed. In order to improve the geometry assurance process in pipe manufacturing at Saab Kockums, this study proposes general guidelines for improvement along with a process and prototype measurement tool for the fitting-pipe methodology. The specially designed prototype measurement tool presents an alternative measurement method that can be used in cramped spaces where it is difficult to access with a 3D-measurement arm, the proposed primary measurement technique. In conclusion, this study indicates that geometry assurance is applicable in low volume manufacturing of complex products and suggests three methods for how it may be achieved. However, each of these methods needs to be further investigated in order to determine their applicability in other low volume manufacturing industries. Further, the prototype measurement tool and process for the fitting-pipe methodology indicates potential for improving the geometry assurance process in pipe manufacturing. However, further work is needed to complete the process for fitting-pipes and to finalize the prototype measurement tool for production use.

Production system development is challenging for manufacturing companies, and development of HMLV production cells entails additional challenges. Thus, the aim of this study is to support the development of a HMLV production cell, and the following research questions were asked: RQ1: What are the challenges of developing a HMLV production cell? RQ2: What are the critical factors to consider when developing a HMLV production cell? RQ3: How can the development of a HMLV production cell be supported? A literature review in combination with a case study were performed to fulfill the aim and answer the research questions. The literature review was conducted to gain knowledge from previous studies, whilst the case study was performed to complement the theoretical findings. The selected case is the development of a HMLV production cell in the department of engine machining at Scania, which is planned to perform production activities for various departments of Scania. The primary data was collected through observations and interviews. The identified challenges of developing a HMLV production cell were production planning, utilization of equipment, product quality and material flow. The identified critical factors to consider when developing a HMLV production cell were production flexibility, production competence, production technology, pilot production, manufacturing strategy, order management system and standardization. The identified challenges of developing a HMLV production cell and the critical factors to consider when developing a HMLV production cell can support manufacturing companies by informing what challenges to expect prior to developing a HMLV production cell, and what critical factors can mitigate these challenges. Two ways of supporting the development of a HMLV production cell are recommended to Scania: creating a structured order management system and performing a pilot production for the milling operation of the core box reparation process. During this study, it was discovered that different HMLV production cells have different capabilities, challenges, and therefore also different critical factors. As such, recommendation for further research is to investigate how the development of different types of HMLV production cells can be supported by using a multiple case study research design, and to compare the challenges and critical factors for the development for the different types of HMLV production cells.

When evaluating low volume roads (LVRs), structural capacity emphasis is minimal since deterioration typically results from environmental factors. However, in cases where LVR’s experience rapidly increased traffic loading, structural condition becomes important. The research objective was to determine whether the Light Weight Deflectometer (LWD) can be used as a structural evaluation tool for LVRs in the aforementioned conditions. This study explored the capability of LWD equipment in evaluating major factors that influence flexible pavement structural capacity: load induced deterioration, soil moisture, and asphalt temperature. Falling Weight Deflectometer (FWD) and LWD tests were performed to measure pavement structural condition. LWD was shown applicable for LVRs experiencing accelerated traffic. The LWD is portable and efficient for LVRs when high rut depths are permitted. The LWD and FWD produced similar trends. The LWD, based on this thesis, can be recommended for use in lieu of FWD to assess structural condition of LVRs for rapidly increased traffic loading.

The problems associated with increased heavy grain truck traffic in rural regions were investigated. Both the short-run incremental costs of accelerated pavement replacement and the long-run incremental costs of upgrading low-volume highways were considered. A set of demand and traffic models was formulated which projects the annual flow of grain from each production zone in an impact region to each elevator, allocates the flows among truck-types, computes the annual trips, gross vehicle weights and axle weights, and assigns the truck trips to the highway network. A set of highway models was also formulated which computes the equivalent single axle loads for each highway section in an impact region and estimates the incremental costs associated with subterminal traffic. The impacts of a newly-formed subterminal-satellite elevator system in rural North Dakota were investigated. The results of the case study indicate that rural collector highways are likely to experience substantial localized impacts from subterminal development but the effects on principal arterials may be minimal. Altogether, $1.14 million in short-run costs and $8.41 million in long-run costs were projected for the impact region. However, the case study roads represent less than 2 percent of the rural arterial and collector highway mileage in the state. If the case-study network represents a microcosm of rural North Dakota, then the statewide short-run and long-run incremental costs may be in the vicinity of $57 million and $420 million respectively. However, regional variations within the state may result in either higher or lower costs for a given elevator system than those projected in the case study. / Ph. D.

Call number: LD2668 .T4 1985 M87 / Master of Science

The product development process for the automotive industry is normally complicated, lengthy, expensive, and risky. Hence, a study on a new concept for Low Volume Automotive Manufacturing (LVAM), used for niche car models manufacturing, is proposed to overcome this issue. The development of a hybrid Knowledge Based (KB) System, which is a blend of KB System, Gauging Absences of Pre-requisites (GAP), and Analytic Hierarchy Process (AHP) is proposed for LVAM research. The hybrid KB/GAP/AHP System identifies all potential elements of LVAM issues throughout the development of this system. The KB System used in the LVAM analyses the gap between the existing and the benchmark organisations for an effective implementation. The novelty and differences in the current research approach emphasises the use of Knowledge Based (KB) System in the planning and designing stages by suggesting recommendations of LVAM implementation, through: a) developing the conceptual LVAM model; b) designing the KBLVAM System structure based on the conceptual LVAM model; and c) embedding Gauging Absences of Pre-requisites (GAP) analysis and Analytic Hierarchy Process (AHP) approach in the hybrid KBLVAM System. The KBLVAM Model explores five major perspectives in two stages. Planning Stage (Stage 1) consists of Manufacturer Environment Perspective (Level 0), LVAM Manufacturer Business Perspective (Level 1), and LVAM Manufacturer Resource Perspective (Level 2). Design Stage (Stage 2) consists of LVAM Manufacturer Capability - Car Body Part Manufacturing Perspective (Level 3), LVAM Manufacturer Capability - Competitive Priorities Perspective (Level 4), and LVAM Manufacturer Capability - Lean Process Optimisation Perspective (Level 5). Each of these perspectives consists of modules and sub-modules that represent specific subjects in the LVAM development. Based on the conceptual LVAM model, all perspectives were transformed into the KBLVAM System structure, which is embedded with the GAP and AHP techniques, hence, key areas of potential improvement are recommended for each activity for LVAM implementation. In order to be able to address the real situation of LVAM environment, the research verification was conducted for two automotive manufacturers in Malaysia. Some published case studies were also used to check several modules for their validity and reliability. This research concludes that the developed KBLVAM System provides valuable decision making information and knowledge to assist LVAM practitioners to plan, design and implement LVAM in terms of business organisation, manufacturing aspects and practices.