Eindringtiefe eines Hydrophobierungsmittels als Funktion der Qualität, des Feuchtigkeitsgehaltes und des Alters des Betons / Penetration depth of a water repellent agent as a function of quality, humidity and age of concrete

Service life and lifetime of a concrete structure are not only depending on mechanical but also on chemical loads. Therefore precautions are often taken into account already in the planning- or construction phase. Certain protective measures such as water repellent treatment need preliminary tests on the finished concrete surface, in order to be applied in an optimal way . The present paper describes the preliminary tests performed on three tunnels of the second section of the Swiss National Highway N5 (Grenchen - Zuchwil) in the area of Solothurn. For the construction of the three tunnels different qualities of concrete and different types of form work were used. Furthermore the selected sections of the tunnels differ also from age and environmental conditions. A new two-chamber measuring cell developped at the Institute for Building Materials of ΕΤΗ-Zurich was applied to determine the capillary suction capacity of selected tunnel sections. Values measured on concrete elements in practice with this new cell are much more reliable than those measured with the traditional Karsten-cell.