Bond of Reinforcemen Under Controlled Confinement.
Abstract
Twelve specimens were tested to determine the local bond stress-slip characteristics of a No. 6 rebar embedded in a 3-inch diameter concrete cylinder. Radial confining stress around the concrete specimen and radial deformation were assumed to be fundamental variables, together with bond stress and slip, needed to properly describe the interface behavior. Configuration independent bond stress-slip, relationships for a short five-lug embedded length were obtained for various degrees of confining pressure. Maximum bond stresses could be increased almost threefold by increasing the confining stress from 500 to 4500 psi at the bar level. Two types of No. 6 bars with different deformations were investigated. In many reinforced concrete structures, the mode of failure is tensile cracking of the concrete. Where it is important to predict failure or severe damage, proper representation of bond is crucial. Principal gain from inclusion of actual bond-slip properties in the interface between steel rebar and concrete is a realistic prediction of cracking. The spacing, width, and extent of cracks in reinforced concrete are dependent on the assumed bond-slip characteristics. Critical Navy reinforced concrete structures, such as missile test cells and graving drydocks, are designed to withstand large deformations under severe blast and strong-motion earthquake loads. The development of design criteria for these structures requires evaluation of their response where severe deterioration of steel concrete interfaces takes place.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1991
- Accession Number
- ADA240142
Entities
People
- L. J. Malvar
Organizations
- Naval Facilities Engineering Service Center