Pozzolanic activity of silica dust

Abstract Highly reactive aggregates and unusually alkali-rich cement call for special precautions in connection with concrete making in Iceland. Search in the past for efficient ways to counteract alkali-aggregate reactions is cited. High hopes are now connected with the pozzolanic use of silica fume from a ferrosilicon plant now under erection. The influence of this dust on cement strength and mortarbar expansion is described.