ABSTRACT
In Fig. 10 the axial and radial displacements over the length of a test specimen for initial loading are shown. The course of the axial displacements was assumed to be approximately linear. With short specimens the realistic course of the axial displacements differs only insignificantly from the linearized approximation. The radial displacements are considerably smaller than the axial displacements. The radial displacements increase with the decrease of the distance to the edge of the specimen and with increasing length of the specimen. This explains the poor bond stiffness of the marginal areas compared with the inner areas. It also clarifies the bad transfer of bond strength in the longer specimens compared with the shorter ones at equal distance of the measuring points to the edge of
REFERENCES
NOTATIONS
Subscripts s steel
Superscripts at the first crack
Cross sectional properties e eccentricity of force
Stresses f stress
Strains ε strain
Lengths ∆ relative axial displacement between steel and concrete
Miscellaneous notations t days
