Abstract:
Concrete - 100 years ago a new building material and today regarded as indispensable - camejust in time to be used from the very beginning of the hydropower era in the World, aroundthe turn of the century. It soon became the preferred material for construction of dams andpower-houses, although the performance with regard to durability proved to be poor in many cases, giving rise for concern. Most prone to damage were dams at mountain sites, exposed toharsh climatic conditions. The problem was obviously one of lack of know-how in the field of concrete technology. An important factor in mix design is the ratio between water and binder.As long as only binder is cement, the term w/c ratio cannot be misunder-stood. With theincreasing use of pozzolana as binder in addition to the cement, the term w/b ration is now widely used. The term w/c ration as used in literature shall be interpreted to include pozzolana.
