A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Probabilistischer Nachweis der Wirksamkeit von Massnahmen gegen fruehe Trennrisse in massigen Betonbauteilen
In order to ensure a desired service lifetime and function (tightness) of a massive concrete structure, it is of great importance to avoid thermal cracking. Therefore, it is indispensable to perform a reliability-based thermal stress analysis to predict the initiation of thermal cracks by considering the parameters of analysis as random variables. The uncertainties depend on the materials in use, their composition and environmental conditions etc. This approach needs a reliability-oriented crack criterion to forecast the effectiveness of countermeasures during design and planning stages. The effectiveness can be described by the so-called thermal cracking index. The cracking index is defined as the ratio of the effective structural tensile strength and the maximum tensile stress in structure. This thesis describes a concept, to evaluate the possibility of thermal cracking based on probability theory. Focusing on mass concrete, the sensitivity of the thermal cracking index with respect to the variation of the parameters is investigated using Monte-Carlo simulations. Calculating the probability of thermal cracking, reliability-oriented crack criteria are defined for a wide use in practice. The proposed model can be used, if a reliable estimation of all load-independent strains and the restraint of the hardening concrete structure as well as the uncertainty of all parameters can be obtained. An application for a railway trough structure is presented. A substantial part of this work was supported by a research grant for the prograrn 'Reliability oriented prediction of thermal stresses in hardening concrete structures'.
Probabilistischer Nachweis der Wirksamkeit von Massnahmen gegen fruehe Trennrisse in massigen Betonbauteilen
In order to ensure a desired service lifetime and function (tightness) of a massive concrete structure, it is of great importance to avoid thermal cracking. Therefore, it is indispensable to perform a reliability-based thermal stress analysis to predict the initiation of thermal cracks by considering the parameters of analysis as random variables. The uncertainties depend on the materials in use, their composition and environmental conditions etc. This approach needs a reliability-oriented crack criterion to forecast the effectiveness of countermeasures during design and planning stages. The effectiveness can be described by the so-called thermal cracking index. The cracking index is defined as the ratio of the effective structural tensile strength and the maximum tensile stress in structure. This thesis describes a concept, to evaluate the possibility of thermal cracking based on probability theory. Focusing on mass concrete, the sensitivity of the thermal cracking index with respect to the variation of the parameters is investigated using Monte-Carlo simulations. Calculating the probability of thermal cracking, reliability-oriented crack criteria are defined for a wide use in practice. The proposed model can be used, if a reliable estimation of all load-independent strains and the restraint of the hardening concrete structure as well as the uncertainty of all parameters can be obtained. An application for a railway trough structure is presented. A substantial part of this work was supported by a research grant for the prograrn 'Reliability oriented prediction of thermal stresses in hardening concrete structures'.
Probabilistischer Nachweis der Wirksamkeit von Massnahmen gegen fruehe Trennrisse in massigen Betonbauteilen
Krauß, Matias (author)
2004
225 Seiten, Bilder, Tabellen, 155 Quellen
Theses
German
| UB Braunschweig | 2004