In the Netherlands a continuous research effort is made to improve the long-term performance of reinforced concrete structures and to arrive at durable repairs whenever a structure shows damage. The paper discusses results of various investigations into reinforcement corrosion due to penetration of deicing salts into concrete. The outstanding performance of composite cements, especially blast furnace slag cement, both with respect to chloride penetration and corrosion progress is shown. The results of an investigation into the critical chloride concentration are presented and the importance of various parameters is highlighted, not only with respect to the time to corrosion but also to the rate also to the rate of corrosion. Effects of changes in the type of road pavement on concrete performance, such as the use of noise reducing black tops of very open asphalt, are considered. Various possibilities to warrant the durability of bridge decks with a very open asphalt wearing layer are discussed, notably those for which specific know-how has been developed in the Netherlands. Finally, some data of a research programme into the effectiveness of repair techniques covering both laboratory and practice tests are presented. (A)
Abstract