Hard coal fly ash complying with EN 450 has been used in Germany and other European countries with increasing success. More than 75 % of the approx. 4.5 million tonnes of hard coal fly ash produced annually in Germany are processed into cement-bound building materials. The quantity of hard coal fly ash used in this sector has remained virtually constant although the production of ready-mix concrete has declined steadily over the last 10 years. The specific quantity of hard coal fly ash used as a concrete additive per cbm of ready-mix concrete has increased. A decisive factor in this was the need-based supply of hard coal fly ash, whereby need-based refers to both quality and quantity. The availability of corresponding quantities of hard coal fly ash was a mainspring of development until well into the 1990s. If one wishes to analyse future development possibilities in the fly ash industry, it is important to understand the area of conflict between concrete technology, economy, ecology and advancing European standardisation. Ecology in particular is gaining increasingly in importance and is intervening in development in many different ways. The importance of hard coal fly ash as an additive will increase. However, it is necessary to further develop the current rules for the use of hard coal fly ash as a concrete additive.
