On Saturday, June 24, five ready mix producers--Dielman Inc., Kuhlman Corp., M and R Redi-Mix, Pahl's Ready Mix, and Williams Brothers Concrete--joined forces to produce and deliver about 4,000 cubic yards of concrete in 8 « hours for the base of a giant water tank. Concrete for the base was a watertight mix that was designed to achieve a 4000 psi compressive strength in 56 days. The tank is part of a $472 million steel mill being built near the town of Delta, Ohio. The concrete work for the plant is a $30 million package involving about 80,000 cubic yards of concrete to be placed over 16 months. Major concrete items in the contract include large water-containment structures, base slabs, foundations, pedestals for steel processing equipment, and the building's floor which will be 12 inches thick in some areas.