scope:

This report is primarily concerned with limiting the width of cracks in structural members that occur principally from restraint of thermal contraction. A detailed discussion of the effects of heat generation and volume changes on the design and behavior of mass reinforced concrete elements and structures is presented. It is written primarily to provide guidance for the selection of concrete materials, mix requirements, reinforcement requirements, and construction procedures necessary to control the size and spacing of cracks. Particular emphasis is placed on the effect of restraint to volume change in both preventing and causing cracking and the need for controlling peak concrete temperature. The quality of concrete for resistance to weathering is not emphasized in recommending reduced cements contents; however, it should be understood that the concrete should be sufficiently durable to resist expected service conditions. The report can be applied to any concrete structure with a potential for unacceptable cracking; however, its general application is to massive concrete members 18 in. or more in thickness.