Mass concrete is defined by the American Concrete Institute as: “any volume of concrete in which a combination of dimensions of the member being cast, the boundary conditions, the characteristics of the concrete mixture, and the ambient conditions can lead to undesirable thermal stresses, cracking, deleterious chemical reactions, or reduction in the long-term strength as a result of elevated concrete temperature due to heat from hydration.” (ACI 207.1R).
Mass concrete has been historically associated with large structures such as dams, bridge piers, and other large volume placements. However, due to the increasingly common use of fast-track construction practices and high-performance concretes with high cementitious contents, mass concrete issues are being experienced in underpinning and foundation repair. Understanding the causes of mass concrete issues (high internal temperatures and temperature-related cracking) is the key to producing a structure that provides many years of service.
The resources below provide information pertaining to material selection, thermal control calculation methods, and construction practices for mass concrete placements.