Repair material properties which influence long-term performance of concrete structures

1995 ◽  
Vol 9 (2) ◽  
pp. 81-90 ◽  
Author(s):  
P.S. Mangat ◽  
M.K. Limbachiya
2020 ◽  
Vol 10 (12) ◽  
pp. 4330
Author(s):  
Hyunjun Jung ◽  
Seok-Been Im ◽  
Yun-Kyu An

This study proposes a probability-based carbonation prediction approach for successful monitoring of deteriorating concrete structures. Over the last several decades, a number of researchers have studied the concrete carbonation prediction to estimate the long-term performance of carbonated concrete structures. Recently, probability-based durability analyses have been introduced to precisely estimate the carbonation of concrete structures. Since the carbonation of concrete structures, however, can be affected by material compositions as well as various environmental conditions, it is still a challenge to predict concrete carbonation in the field. In this study, the Fick’s first law and a Bayes’ theorem-based carbonation prediction approach is newly proposed using on-site data, which were obtained over 19 years. In particular, the effects of design parameters such as diffusion coefficient, concentration, absorption quantity of CO2, and the degree of hydration have been thoroughly considered in this study. The proposed probabilistic approach has shown a reliable prediction of concrete carbonation and remaining service life.


Author(s):  
Carl E. Jaske

This paper reviews the metallurgy and behavior of centrifugally cast heat-resistant alloys for ammonia, methanol, and hydrogen reformer furnaces. The alloys include HK and HP, as well as proprietary versions of these materials produced by various foundries. Alloying and metallurgical factors that affect resistance to oxidation, carburization, and high temperature creep are discussed. Examples of the effects of environment and temperature on material behavior are provided. Finally, the use of material properties to predict the long-term performance of reformer furnace components is reviewed.


2003 ◽  
Vol 1832 (1) ◽  
pp. 217-223 ◽  
Author(s):  
Donald E. Watson

Stone matrix asphalt (SMA) and Superpave® represent relatively new mix design technologies in the United States. Therefore, a condition survey was conducted of mixes that had been in service for several years to evaluate the long-term performance of SMA and Superpave projects. This study is a follow-up to a 1995 review of SMA projects and a 1998 review of Superpave projects. Both SMA and Superpave are acknowledged to be rut-resistant mixes, and this resistance was shown to be the case during this project review. However, a significant amount of cracking occurred early in the life of some of these mixtures. Overall, the SMA mixtures appeared to be more durable than the Superpave mixtures evaluated. The SMA mixtures have been in place about 2½ years longer than the Superpave mixtures, but the overall condition is about the same. Some of the primary conclusions from the survey are as follows: both SMA and Superpave mixtures were shown to be rut-resistant even when placed on facilities with high traffic volume; much of the observed cracking, especially load cracking, appeared to be more related to problems other than mix design or material properties; and SMA mixtures can be expected to last longer than Superpave mixtures before reaching the same condition level.


2021 ◽  
Vol 42 ◽  
pp. 102467
Author(s):  
Naveen Krishnan ◽  
Deepak K. Kamde ◽  
Zameel Doosa Veedu ◽  
Radhakrishna G. Pillai ◽  
Dhruvesh Shah ◽  
...  

2017 ◽  
Vol 7 (1) ◽  
pp. 57-72
Author(s):  
K. Van Breugel ◽  
T. A. Van Beek

Ageing of old and modern concrete structures – Observations and researchABSTRACTAgeing is an inherent feature of nature. Yet it seems to be a rather new topic in both science and engineering. The main reason for increasing attention for ageing as a topic is the growing awareness that, particularly in industrialized countries, ageing of our assets is a financial burden for the society and affects the overall sustainability of our planet. In this contribution, the urgency and challenges of ageing of concrete structures are addressed. The complexity of ageing problems will be illustrated by looking in more detail to the evolution in concrete mix design and the consequences thereof for the long-term performance of concrete structures. Emphasis will be on ageing of concrete infrastructure and justification of research on ageing phenomena.Keywords: infrastructure; sustainability; ageing; mix design; autogenous shrinkage; codes. Envejecimiento de antiguas y modernas estructuras de concreto - Observaciones e investigacionesRESUMENEl envejecimiento es una característica inherente de la naturaleza. Sin embargo, parece ser un tema bastante nuevo en la ciencia y la ingeniería. La principal razón para aumentar la atención por el envejecimiento como tema es la creciente conciencia de que, en particular en los países industrializados, el envejecimiento de nuestros activos es una carga financiera para la sociedad y afecta la sostenibilidad global de nuestro planeta. En esta contribución se abordan la urgencia y los desafíos del envejecimiento de las estructuras de concreto. La complejidad de los problemas de envejecimiento se ilustra examinando con más detalle la evolución del diseño de la mezcla de concreto y sus consecuencias para el rendimiento a largo plazo de las estructuras de concreto. Se hace hincapié en el envejecimiento de las infraestructuras de concreto y en la justificación de la investigación sobre fenómenos de envejecimiento.Palabras clave: infraestructura; sostenibilidad; envejecimiento; mezcla de diseño; contracción autógena; códigos. Envelhecimento estruturas de betão antigos e modernos - Observações e pesquisaRESUMOO envelhecimento é uma característica inerente à natureza. No entanto, parece ser um bastante novo tópico em ciência e engenharia. A principal razão para uma maior atenção por tema envelhecimento é a consciência crescente de que, particularmente nos países industrializados, o envelhecimento dos nossos ativos é um encargo financeiro para a sociedade e afeta a sustentabilidade global do nosso planeta. Nesta contribuição a urgência e os desafios de estruturas de concreto envelhecimento são abordados. A complexidade dos problemas de envelhecimento está ilustrada em mais pormenor através da análise da evolução do desenho da mistura de betão e o seu impacto sobre o desempenho a longo prazo das estruturas de betão. A ênfase é colocada na infra-estrutura de envelhecimento do concreto e justificação da pesquisa sobre os fenómenos de envelhecimento.Palavras-chave: infra-estrutura; sustentabilidade; envelhecimento; misture projeto; retração autógena; códigos.


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