Mass concrete in which large stones, each of 100 lb (45.4 kg) or more, are placed and embedded as the concrete is deposited; such a stone is called a pudding stone or plum; they are usually not less than 6 in. (15 cm) apart and not closer than 8 in. (20 cm) to any exposed surface. Also see rubble concrete.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.