Unit, direct support, and general support maintenance repair parts and special tools lists (including depot maintenance repair parts and special tools lists) : mixer, rotary tiller, DED, 4 wheel, pneumatic tired, self-propelled, NSN 3895-00-883-0437, FWD Corporation model B2-ll7l.

"June 1992."

Operator, organizational, direct support and general support maintenance manual : mixer, rotary tiller, DED, 4 wheel pneumatic tired, self-propelled (FWD Corporation model B2-1171) (FSN 3895-883-0437).

Includes index.

Operator's manual : snow removal unit, self-propelled, gasoline driven, rotary, wheel mtd, winterized (FWD model S-349-V), serial numbers G30681 through G30690 and G30750 through G30759 FSN 3825-810-7074.

"December 1961."

Organizational maintenance repair parts and special tools lists : mixer, rotary tiller ded, 4 wheel, pneumatic tired, self-propelled, NSN 3895-00-883-0437, FWD Corporation model B2-ll7l.

Includes index.

Direct support and general support maintenance repair parts and special tools lists (including depot maintenance repair parts and special tools lists) : mixer, rotary tiller DED, 4 wheel, pneumatic tired, self-propelled, NSN 3895-00-883-0437, FWD Corporation model B2-1171.

Includes index.

Caracterização estrutural de infra-estruturas de transporte através de métodos de auscultação não destrutivos

A avaliação da capacidade de carga de infra-estruturas de transportes em serviço, tendo em vista a estimativa da vida residual e o eventual dimensionamento do reforço da estrutura, é realizada recorrendo cada vez mais a ensaios de carga não destrutivos. Esta metodologia permite depois, através de um processo de retroanálise, estabelecer um modelo de comportamento estrutural que reproduza, de forma tão próxima quanto possível, as condições reais da solicitação de tráfego e a resposta da infra-estrutura. Os métodos analíticos utilizados na avaliação estrutural consistem na verificação da capacidade de carga e estimativa da vida útil da estrutura, através de critérios que relacionam a acção do tráfego e os consequentes estados de tensão e de deformação induzidos nas camadas da estrutura e na fundação. O Deflectómetro de Impacto (FWD) e o Deflectómetro de Impacto Portátil (DIP) são, actualmente, dois dos equipamentos de uso mais generalizado para a realização de ensaios de carga. No presente trabalho é apresentado o estado de arte da avaliação da capacidade de carga de infra-estruturas de transportes, sendo efectuada uma descrição com maior pormenor do FWD e do DIP. São apresentados resultados de alguns estudos efectuados em Portugal e no mundo utilizando estes dois equipamentos. O caso de estudo apresentado nesta dissertação consiste na modelação estrutural de um trecho experimental de uma plataforma ferroviária, efectuada com base em ensaios de carga realizados com o FWD e DIP sobre a camada de sub-balastro granular. Neste contexto foi analisada a eficiência dos ensaios de carga e o grau de correlação entre os resultados obtidos pelos dois equipamentos.

Análise comparativa de metodologias para avaliação das condições de fundação de pavimentos rodoviários

Dissertação para obtenção do Grau de Mestre em Engenharia Civil – Perfil de Construção

Modelação do comportamento mecânico de vias-férreas

Dissertação para obtenção do Grau de Mestre em Engenharia Civil

Contribuição para a avaliação estrutural de infraestruturas rodoviárias por métodos não destrutivos

Dissertação para obtenção do Grau de Mestre em Engenharia Civil – Perfil de construção

Airport pavements evaluation

The airport pavement deteriorates during service due to traffic and climate effects therefore systematic monitoring is required in order to assess their structural and functional condition. The aim of this work is to present the methodologies used nowadays for airport pavement evaluation and to contribute to their improvement in structural analysis area The main aspects that are addressed are the application of the Ground Penetrating Radar (GPR) and the use of the Falling Weight Deflectometer (FWD) tests, for structural evaluation, and the use of the GRIP tester and the measurement of texture depth of the wearing course layer, for the functional evaluation of the runway. Also, freeware computer softwares used to design new runways (FAARFIELD and COMFAA) are presented and examples are given. Case studies are described both for structural and functional evaluation.

Comparação de diferentes métodos de avaliação da capacidade de carga de pavimentos rodoviários

Dissertação de mestrado integrado em Engenharia Civil

Field Evaluation of Elliptical Fiber Reinforced Polymer Dowel Performance, June 2005

Fiber reinforced polymer (FRP) composite materials are making an entry into the construction market in both buildings and pavements. The application to pavements so far has come in the form of joint reinforcement (dowels and tie bars). FRP resistance to salt corrosion in dowels has made it an alternative to standard epoxy-coated steel dowels for pavements. Iowa State University has completed a large amount of laboratory research to determine the diameter, spacing, and durability of FRP dowels. This report documents the performance of elliptical FRP dowels installed in a field situation. Ten joints were monitored in three consecutive test sections, for each of three dowel spacings (10, 12, and 15 inches) including one instrumented dowel in each test section. The modulus of dowel bar support was determined using falling weight deflectometer (FWD) testing and a loaded crawl truck. FWD testing was also used to determine load transfer efficiency across the joint. The long-term performance and durability of the concrete was also evaluated by monitoring faulting and joint opening measurements and performing visual distress surveys at each joint. This report also contains similar information for standard round, medium elliptical, and heavy elliptical steel dowels in a portion of the same highway. In addition, this report provides a summary of theoretical analysis used to evaluate joint differential deflection for the dowels.

Field Evaluation of Elliptical Fiber Reinforced Polymer Dowel Performance, June 2003

Fiber composite materials (FRP) are making an entry into the construction market in both buildings and pavements. The application to pavements comes in the form of joint reinforcement (dowels and tie bars) to date. FRP resistance to salt corrosion in dowels has made it an alternative to standard epoxy coated dowels for pavements. Iowa State University has completed a large amount of laboratory research into the determination of diameter, spacing, and durability of FRP dowels. This report documents the installation of a series of FRP elliptical-shaped dowel joints (including instrumented units) in a field situation and the beginning of a two-year study to compare laboratory results to in-service pavements. Ten joints were constructed for each of three dowel spacings of 10, 12, and 15 inches ( 254, 305, and 381 mm) with one instrumented joint in each test section. The instrumented bars will be load tested with a loaded truck and FWD testing.

Utility Cut Repair Techniques— Investigation of Improved Cut Repair Techniques to Reduce Settlement in Repaired Areas, December 2005

Pavement settlement occurring in and around utility cuts is a common problem, resulting in uneven pavement surfaces, annoyance to drivers, and ultimately, further maintenance. A survey of municipal authorities and field and laboratory investigations were conducted to identify the factors contributing to the settlement of utility cut restorations in pavement sections. Survey responses were received from seven cities across Iowa and indicate that utility cut restorations often last less than two years. Observations made during site inspections showed that backfill material varies from one city to another, backfill lift thickness often exceeds 12 inches, and the backfill material is often placed at bulking moisture contents with no Quality control/Quality Assurance. Laboratory investigation of the backfill materials indicate that at the field moisture contents encountered, the backfill materials have collapse potentials up to 35%. Falling Weight Deflectometer (FWD) deflection data and elevation shots indicate that the maximum deflection in the pavement occurs in the area around the utility cut restoration. The FWD data indicate a zone of influence around the perimeter of the restoration extending two to three feet beyond the trench perimeter. The research team proposes moisture control, the use of 65% relative density in a granular fill, and removing and compacting the native material near the ground surface around the trench. Test sections with geogrid reinforcement were also incorporated. The performance of inspected and proposed utility cuts needs to be monitored for at least two more years.

Rehabilitation of Concrete Pavements Utilizing Rebblization and Crack and Seat Methods, June 2005

Deterioration in portland cement concrete (PCC) pavements can occur due to distresses caused by a combination of traffic loads and weather conditions. Hot mix asphalt (HMA) overlay is the most commonly used rehabilitation technique for such deteriorated PCC pavements. However, the performance of these HMA overlaid pavements is hindered due to the occurrence of reflective cracking, resulting in significant reduction of pavement serviceability. Various fractured slab techniques, including rubblization, crack and seat, and break and seat are used to minimize reflective cracking by reducing the slab action. However, the design of structural overlay thickness for cracked and seated and rubblized pavements is difficult as the resulting structure is neither a “true” rigid pavement nor a “true” flexible pavement. Existing design methodologies use the empirical procedures based on the AASHO Road Test conducted in 1961. But, the AASHO Road Test did not employ any fractured slab technique, and there are numerous limitations associated with extrapolating its results to HMA overlay thickness design for fractured PCC pavements. The main objective of this project is to develop a mechanistic-empirical (ME) design approach for the HMA overlay thickness design for fractured PCC pavements. In this design procedure, failure criteria such as the tensile strain at the bottom of HMA layer and the vertical compressive strain on the surface of subgrade are used to consider HMA fatigue and subgrade rutting, respectively. The developed ME design system is also implemented in a Visual Basic computer program. A partial validation of the design method with reference to an instrumented trial project (IA-141, Polk County) in Iowa is provided in this report. Tensile strain values at the bottom of the HMA layer collected from the FWD testing at this project site are in agreement with the results obtained from the developed computer program.