Volume 6, Issue 2 (March 1978)
Use of Pelletized Slag in Concrete Masonry Units
This paper contains a brief description of the slag pelletizer and the external pressures which led to its development. Pelletized expanded slag is an improved lightweight aggregate for the concrete masonry market. When compared to the earlier lightweight slag aggregates, the improvement manifests itself by a 20% reduction in cement contents for equal compressive strength masonry units. In addition, the water absorption of the masonry is reduced, the green strength is increased, and the visual properties of color and texture are improved. Research work and field trials indicate that the latent hydraulic property of the slag is available in the manufacture of block and brick masonry to further reduce added cementitious binder contents and thereby conserve energy. This can be accomplished by partially grinding the slag at a block plant to produce a self-cementing aggregate. It was also shown that slag fines may be partially replaced or extended by silica flour under some conditions of use.