MONITORING OF THE WATER DISTRIBUTION IN CONCRETE STRUCTURES

摘要

Frost damage in concrete is in principal caused by exceeding the critical degree of water saturation [1]. To obtain information on the water saturation in members of concrete buildings in connection with freezing of water, the humidity and temperature of concretes has been monitored in different bridges, locks, tunnels etc. The so-called multiring electrode measuring system has been used in connection with temperature sensors. The buildings cover the exposition classes XF1 to XF4 according to EN 206-1. The continuously monitoring of the electrolytic resistivity and the temperature data must be converted into water saturation values using calibration curves determined in the laboratory. For a period of up to 6 years, the degree of water saturation has been observed. From the data the long-term behaviour as well as short-term occasions influencing the water saturation degree can be evaluated. For the prediction of the service life of concrete in the case of frost resistance the data are compelling to describe the action part in building constructions.