Schadensrisiko und Schadensentwicklung in Betonfahrbahndecken als Folge einer Alkali-Kieselsäure-Reaktion

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Concrete pavements are, apart from mechanical influence of traffic, especially subject to climatically conditioned and continuously changing thermal and hygric exposure as well as further stress due to constructional features arising e.g. from the building technique of a concrete pavement. As the case may be, this basic exposure meets an alkali-silica reaction (ASR), causing distinctive expansions. Although not inevitably, the thusly implied overall strain often leads to expanding broad cracks in carriageways. The proportion of ASR to this is practically unknown. Besides, ASR leads to decreased resistance of the concrete, which may as well result in cracks. Nonetheless, this cannot be quantified at this moment. Therefore, the actual mechanisms of the formation of cracks are unknown. This also excludes the appliance of well-directed countermeasures, which could e.g. consist of constructive means in different stages. The goal of the research project is to fill the existing knowledge gaps that is to analyse the demand due to ASR in the composite material concrete pavement under the complex exposure and resistance occurring in practice, to forecast the damage risk as well as gaining knowledge regarding an improved constructive design of the composite material. For this purpose, calculative analyses based on a complex numerical model using realistic constitutive equations are executed in addition to extensive experimental fracture mechanical examinations aiming at a determi-nation of the temporal variation of strength and deformation of concrete due to ASR.