Stiffness of reinforced concrete walls resisting in-place shear -- Tier 2: Aging and durability of concrete used in nuclear power plants. Final report
- Sozen and Moehle, Urbana, IL (United States)
Reinforced concrete walls are commonly used in power-plant construction to resist earthquake effects. Determination of wall stiffness is of particular importance for establishing design forces on attached equipment. Available experimental data indicate differences between the measured and calculated stiffness of walls in cases where concrete mechanical properties are well defined. Additional data indicate that in-situ concrete mechanical properties may differ significantly from those specified in design. The work summarized in this report was undertaken to investigate the mechanical properties of concrete considering aging and deterioration. Existing data on mechanical properties of concrete are evaluated, and new tests are carried out on concrete cylinders batched for nuclear power plants and stored under controlled conditions for up to twenty years. It is concluded that concretes batched for nuclear power plants commonly have 28-day strength that exceeds the design value by at least 1000 psi. Under curing conditions representative of those in the interior of thick concrete elements, strength gain with time can be estimated conservatively using the expression proposed by ACI Committee 209, with strengths at 25 years being approximately 1.3 times the 28-day strength. Young`s modulus can be estimated using the expression given by ACI Committee 318. Variabilities in mechanical properties are identified. A review of concrete durability identified the main causes and results of concrete deterioration that are relevant for the class of concretes and structures commonly used in nuclear power plants. Prospects for identifying the occurrence and predicting the extent of deterioration are discussed.
- Research Organization:
- Electric Power Research Inst. (EPRI), Palo Alto, CA (United States); Sozen and Moehle, Urbana, IL (United States)
- Sponsoring Organization:
- Electric Power Research Inst., Palo Alto, CA (United States)
- OSTI ID:
- 257418
- Report Number(s):
- EPRI-TR-102731-Tier2; TRN: AHC29615%%115
- Resource Relation:
- Other Information: PBD: Dec 1995
- Country of Publication:
- United States
- Language:
- English
Similar Records
Cost-Benefit Analysis of High-Strength Materials for Safety-Related Nuclear Reinforced Concrete Shear Walls
A yield line evaluation methodology for reinforced concrete structures