Q.: Your article on low density concretes, (March 1981, page 253) has stimulated our interest. We would appreciate knowing where to look or call for suppliers of expanded polystyrene beads who are at present furnishing this product in the open market.

A.: These beads are made by Styropor Division, BASF Wyandotte Corporation, Box 181, Parsippany, New Jersey 07054. They are undoubtedly made by other manufacturers as well, but we have not been able to ascertain who the other manufacturers are.

You may be interested in two reports on concrete made with polystyrene beads:

"Properties of Expanded Polystyrene Concrete and Applications for Pavement Subbases," by Amir N. Hanna, Research and Development Bulletin RD055.01P, published by Portland Cement Association, Skokie, Illinois 60077.

"Polystyrene Aggregates," by D. J. Cook, Constructional Review (Australia), August 1972, pages 52, 53.