On the service life of concrete exposed to frost action

A theory is presented for the service life of concrete exposed to frost action. It is based on a separation of the frost resistance problem in two parts. Part 1, that is only a function of the material itself, and which is expressed in terms of a critical water content, or a degree of saturation, which is a "fracture value" being almost independent of the external conditions (except for the lowest temperature and the internal salt concentration). The critical degree of saturation is a consequence of the existence of a critical distance of water transfer during freezing. Some experimental data for the critical distance are given. Part 2, that is a function of the wetness of the environment, and which is expressed in terms of a time function of the capillary water uptake, and the long term water absorption in the air-pore system. Probably, it is also a function of the salt concentration outside and inside the concrete. It is shown in the paper, that the long term water absorption in pure water can often be described and extrapolated by simple time functions. (Less)