Thesis (M.S.)--Brigham Young University. Dept. of Civil and Environmental Engineering, 2006. / Includes bibliographical references (p. 43-46).

Este trabalho de pesquisa foi realizado na busca de melhor entendimento do comportamento estrutural de pavimentos de concreto no que tange a transferência de carga em juntas, de quais os fatores que influenciam essa transferência de esforços nas juntas e a determinação, em caráter preliminar, de como as condições climáticas vigentes na área tropical dos estudos afeta o fenômeno. Para a realização dos experimentos foi empregada a pista experimental USP/FAPESP, construída em 1999, e até então não empregada para a determinação dos efeitos de transferência de cargas em juntas com e sem barra de transferência de carga. Paralelamente, para retroanalisar os parâmetros de transferência de carga, foram necessárias a avaliação e a análise estrutural de respostas a carregamentos dinâmicos das placas de concreto da pista experimental, possibilitando a determinação de diversos parâmetros em jogo, em especial, do módulo de elasticidade de concretos e do módulo de reação do subleito. Os estudos permitiram determinar que a ausência de barras de transferência de cargas em juntas transversais torna menos eficiente tal transferência além de apresentar nesse caso forte dependência da temperatura do concreto. Em juntas com barras de transferência de carga, para qualquer época do ano, a transferência de cargas é sempre igual ou superior a 90%, aproximadamente, independentemente da geometria das placas. Não existindo tais dispositivos o valor da transferência de cargas variou de 60 a 75%. Não foram observadas dependências importantes quanto a diferentes níveis de carregamento durante os testes, bem como para espessuras de placas de concreto, em placas com barras de transferência. Observou-se, também, embora em escala inferior ao que se narra na literatura passada, que o módulo de reação do subleito para carga de borda é maior que aquele para carga de centro. As faixas de valores de módulos de elasticidade para concretos de placas e para concretos compactados com rolo em sub-bases coincidiram com as faixas de valores encontrados em laboratório com medidas efetuadas na época da construção dos pavimentos. O processo de retroanálise com o programa ISLAB2000 mostrou-se um recurso valioso para a parametrização dos pavimentos de concreto estudados. / This research was proposed aiming an in deep study of the mechanism of load transfer across concrete pavement joints including the analysis of which factors influence such load transfers with special regards to the climate factors as concrete temperature. The concrete pavements under study were built in 1999 as a research supported by FAPESP, whose experimental sections has not been used before for such a goal. Backcalculation techniques were employed to analyze deflection data collected with FWD tests over the slabs and it was possible to define values for the test sections materials parameters like concrete modulus of elasticity and the modulus of subgrade reaction. Tests detected loss of load transfer efficiency on the dependence of concrete temperature for non dowelled joints. For dowelled joints, whatever the season of the year or period of the day, joint load transfer efficiency was at least 90% approximately. However, without dowels, efficiency ranged from 60 to 75%. No expressive dependence on the load level was observed during tests, as well as on the slab thicknesses, for cases of dowelled joints. It was observed the increase in the value of the modulus of subgrade reaction when loads were applied in joint position, although not so expressive as sometimes described in the literature. Ranges for concrete and rolled compacted concrete modulus of elasticity resulted similar to former values got from the construction period in laboratory. Therefore, backcalculation procedures using ISLAB2000 software is understood as a valuable tool for concrete slab characterization.

Since 2006, research funded by the Texas Department of Transportation (TxDOT) has evaluated the use of coatings and sealers for mitigating expansion due to alkali-silica reaction (ASR) and/or delayed ettringite formation (DEF) in hardened concrete. The report herein includes a project summary of previous work in Phase I, led by Racheal Lute (2008) and Charles Rust (2009). The Phase II research, described in this thesis, established concrete exposure blocks and NCHRP 244 Series II testing as the cornerstones of characterizing coating effectiveness. The studies assessed coating system performance by examining the contribution of steel reinforcement, the effects of aggregate reactivity, the size limitations of treatments, and the impact of painted concrete substrates. Lastly, this thesis describes the preliminary results of a field study site of columns supporting a flyover, and a concrete exposure block site in Houston, Texas. Overall, the results are encouraging as several coatings have reduced expansion by lowering internal relative humidity.

Thesis (M.S.)--University of Texas at El Paso, 2008. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (Ph. D.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains xvii, 314 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 264-270).

Thesis (M.S.)--West Virginia University, 2005 / Title from document title page. Document formatted into pages; contains vii, 61 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 51).

Thesis (M.S.)--University of Tennessee, Knoxville, 2004. / Title from title page screen (viewed Sept. 22, 2004). Thesis advisor: Edwin G. Burdette. Document formatted into pages (ix, 82 p. : ill. (some col.)). Vita. Includes bibliographical references (p. 62-68).

Thesis (Professional Degree)--University of Missouri, School of Mines and Metallurgy, 1935. / The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed June 9, 2010) Includes bibliographical references (p. 36) and index (p. 37).

Thesis (M.S.)--University of Texas at El Paso, 2009. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains viii, 75 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 61-62).