Title: 207.1R-96: Mass Concrete
Publication: Technical Documents
Appears on pages(s): 42
Keywords: admixtures; aggregate gradation; aggregate size; aggregates; air entrainment; arch dams; batching; bridge piers; cements; compressive strength; concrete construction; concrete dams; cooling; cracking (fracturing); creep; curing; diffusivity; durability
Note: A newer version of this document exists. This document was replaced by 207.1R-05.
Mass concrete is "any volume of concrete with dimensions large enough to require that measures be taken to cope with generation of heat from hydration of the cement and attendant volume change to minimize cracking." The design of mass concrete structures is generally based on durability, economy, and thermal action, with strength often being a secondary concern. Since the cement-water reaction is exothermic by nature, the temperature rise within a large concrete mass, where the heat is not dissipated, can be quite high. Significant tensile stresses may develop from the volume change associated with the increase and decrease of temperature within the mass. Measures should be taken where cracking due to thermal behavior may cause loss of structural integrity and monolithic action, or may cause excessive seepage and shortening of the service life of the structure, or may be esthetically objectionable. Many of the principles in mass concrete practice can also be applied to general concrete work whereby certain economic and other benefits may be realized. This report contains a history of the development of mass concrete practice and discussion of materials and concrete mix proportioning, properties, construction methods and equipment, and thermal behavior. It covers traditionally placed and consolidated mass concrete, and does not cover roller compacted concrete. Mass concrete practices were largely developed from concrete dam construction, where temperature-related cracking was first identified. Temperature-related cracking has also been experienced in other thick-section concrete structures, including mat foundations, pile caps, bridge piers, thick walls, and tunnel linings.