Probabilistic modelling of concrete structures degradation

Probabilistic modelling of concrete structures degradation

en

Sulfate attack is a set of complex and overlapping chemical and physical processes caused by reactions of numerous cement components with sulfates originating from external or internal sources. These processes can lead to eventual deterioration of concrete composition and properties; in addition, these reactions depend on the environmental exposure, including access of moisture and temperature changes. In the context of performance-based approaches, sustainability consideration and whole life costing, suitable models, which can reliably predict the behavior of hydrated cement systems of concrete structures subjected to sulfate attack during the service life, are needed. A consistent approach to the durability assessment of concrete structures is recommended, i.e. fully probabilistic durability design, which necessarily requires the utilization of stochastic approaches. The present work is restricted to models for the description of concrete under the external sulfate attack. The primary sources of external sulfates are natural sulfates in soils or dissolved in ground water, sulfates originating from the atmospheric pollution or from the decomposition and oxidation of proteins in waste water. Several models for concrete corrosion rate are presented, compared and some parametric analyses are shown.

Sulfate attack is a set of complex and overlapping chemical and physical processes caused by reactions of numerous cement components with sulfates originating from external or internal sources. These processes can lead to eventual deterioration of concrete composition and properties; in addition, these reactions depend on the environmental exposure, including access of moisture and temperature changes. In the context of performance-based approaches, sustainability consideration and whole life costing, suitable models, which can reliably predict the behavior of hydrated cement systems of concrete structures subjected to sulfate attack during the service life, are needed. A consistent approach to the durability assessment of concrete structures is recommended, i.e. fully probabilistic durability design, which necessarily requires the utilization of stochastic approaches. The present work is restricted to models for the description of concrete under the external sulfate attack. The primary sources of external sulfates are natural sulfates in soils or dissolved in ground water, sulfates originating from the atmospheric pollution or from the decomposition and oxidation of proteins in waste water. Several models for concrete corrosion rate are presented, compared and some parametric analyses are shown.