On Mathematical Models of Degradation Processes According to ISO16204 and fib Model Code

Abstract

The main factors affecting the service life of concrete structures are the presence of chlorideions and carbon dioxide, alternating frost action and mechanical stresses on the structure. In practice, these effects can be taken into account by using math-ematical modelling of these phenomena. In thiscontribution, the authors focus on the processes of chlorideions and carbon dioxide (carbonation process) diffusion through concrete and the associated subsequent corrosion of reinforcement. Math-ematical models recommended by the fibModel Code and ISO 16204 are described and the effect of simultaneous environmental and mechanical load on the service life of the structure is discussed. The models are used to study the residual service life of a simple reinforced concrete frame bridgebased on the percentage loss of reinforcement area analysis over time.The main factors affecting the service life of concrete structures are the presence of chlorideions and carbon dioxide, alternating frost action and mechanical stresses on the structure. In practice, these effects can be taken into account by using math-ematical modelling of these phenomena. In thiscontribution, the authors focus on the processes of chlorideions and carbon dioxide (carbonation process) diffusion through concrete and the associated subsequent corrosion of reinforcement. Math-ematical models recommended by the fibModel Code and ISO 16204 are described and the effect of simultaneous environmental and mechanical load on the service life of the structure is discussed. The models are used to study the residual service life of a simple reinforced concrete frame bridgebased on the percentage loss of reinforcement area analysis over time.