- Author
- Clifton, J. R. | Knab, L. I.
- Title
- Service Life of Concrete.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Sponsor
- Nuclear Regulatory Commission, Washington, DC
- Report
- NISTIR 89-4086, June 1989, 150 p.
- Distribution
- Available from National Technical Information Service
- Keywords
- concretes; degradation; service life; mathematical models; corrosion mechanisms; accelerated tests; durability; permeability | life (durability)
- Identifiers
- radioactive waste management; underground disposal; low-level radioactive wastes
- Abstract
- The U.S. Nuclear Regulatory Commission (NRC) has the responsibility for developing a strategy for the disposal of low-level radioactive waste (LLW). An approach being considered for their disposal is to place the waste forms in concrete vaults buried in th earth. A service life of 500 years is required for the concrete vaults as they may be left unattended for much of their lives. The report examines the basis for making service life predictions based on accelerated testing and mathematical modeling of factors controlling the durability of concrete buried in the ground. Degradation processes are analyzed based on considerations of their occurrence, extent of potential damage, and mechanisms. A recommended research plan for developing methods for predicting the service life of concrete is presented. Concepts of quality and factors affecting quality of concrete are discussed. Permeability is discussed in terms of the water-to-cement ratio, the pore structure of concrete, and the effects of cracks.