Q.: Would you please help me find some information on dispensing devices for truck mixers for introducing superplasticizers into concrete?

One was shown in your article "Flowing Concrete," in the January 1979 issue.

A.: The dispenser pictured on page 27 is made in Germany. We know of two dispensers made in America. One is normally mounted lower down on the truck mixer and doesn't feed by gravity but operates by air pressure from the brake system. It is known as the Melment Truck Dispenser, sells for about $100, and can be obtained through American Admixtures Corporation, 5909 North Rogers Avenue, Chicago, Illinois 60646; phone 312-286-3737. Another brand is said to be available in more than one size for mounting on various sizes of truck mixers. It is available from W.R. Grace & Company, 62 Whittemore, Cambridge, Massachusetts 02140; phone 617-876-1400.