1. ERDC Knowledge Core
2. Pre - Engineer Research and Development Center (ERDC)
3. Concrete Laboratory - (8/1/1972 - 4/16/1978)
4. Publication
5. Miscellaneous Paper

Title:	Determination of maximum concrete placement temperatures for Martins Fork Dam
Authors:	United States. Army. Corps of Engineers. Nashville District Bombich, Anthony A.
Keywords:	Computer programs Concrete placing Concrete temperature Concrete thermal properties Finite element method Martins Fork Dam
Publisher:	Concrete Laboratory (U.S.) Engineer Research and Development Center (U.S.)
Series/Report no.:	Miscellaneous paper (U.S. Army Engineer Waterways Experiment Station) ; C-77-7.
Description:	Miscellaneous paper Abstract: Finite element method computer programs were used to calculate the temperature rise, transient temperature change, and resulting thermal strains during simulated construction of Martins Fork Dam. The investigation was conducted in two phases. Phase I, involving temperature calculations only, was performed to provide temperature rise data upon which to base a revised maximum allowable concrete placement temperature that would reduce the potential for thermal cracking. This information was needed before opening construction bids. As a result of Phase I, the recommended maximum allowable placement temperature was reduced from 85°p to 65°F for concrete with pozzolan replacement and to 60°F for concrete without pozzolan. Phase II was conducted after aggregate sources were selected to verify the placement temperatures selected in Phase I. Thermal properties of the concrete used as input to the temperature calculation program were modified as dictated by the results of thermal diffusivity tests of aggregate samples and because of increased heat of hydration from the cement accepted for Martins Fork Dam. Computer temperature simulations used the revised thermal properties and new maximum placement temperatures. Two thermal stress/strain simulations used calculated temperature distributions to calculate thermal stresses and strains. Results showed that when exposed to normal ambient temperatures, surface tensile strains reached 34 percent of estimated tensile strain capacity. When exposed to an extreme mean ambient temperature drop of 30°F sustained for several days simulating a cold front, tensile strains in the dam reached 95 percent of strain capacity. It was concluded that the selected maximum allowable concrete placement temperatures were acceptable and that protection against rapid and sustained ambient temperature drops as from exposure to cold fronts would best be achieved by insulation of exposed concrete surfaces rather than by further reduction in placement temperature.
Rights:	Approved for public release; distribution is unlimited.
URI:	http://hdl.handle.net/11681/11523
Appears in Collections:	Miscellaneous Paper