Title:
Stresses and Strains in Composite Concrete Beams Subjected to Differential Shrinkage
Author(s):
Johan Silfwerbrand
Publication:
Structural Journal
Volume:
94
Issue:
4
Appears on pages(s):
347-353
Keywords:
bond-slip model; differential shrinkage; normal stress; shear stress;
strain; tests;
DOI:
10.14359/485
Date:
7/1/1997
Abstract:
Stresses due to differential shrinkage, i.e., shrinkage difference between the new-cast overlay and existing base, must be considered in repaired concrete structures. A new model has been developed to determine strain, normal stresses, and shear stresses in overlaid beams. The model is based on a linear relationship between slip and shear stress at the interface. Full slip, partial bond, and complete bond can be dealt with in the model. Measurements from two 6 and 8 m (19.7 and 26.2 ft) long overlaid concrete beams show strain concentrations at the beam ends, a result that is consistent with the model prediction. Using the strain measurements in the model results in calculated normal and shear stresses below available concrete strength. No cracks were found in the overlay, base, or at the interface.