Plain concrete prisms were tested under three-point-bending by a displacement control actuator. Along the predicted crack path wire strain gages were attached. From the measured strains it was found that at unloading compressive stresses were acting along the crack surface…
Plain concrete prisms were tested under three-point-bending by a displacement control actuator. Along the predicted crack path wire strain gages were attached. From the measured strains it was found that at unloading compressive stresses were acting along the crack surface near the crack tip and that these compressive stresses caused tensile stresses in the concrete ahead of the crack tip. Both the compressive and tensile stresses increased with loading cycles. When the tensile stresses became large enough to cause cracking, the crack propagated. This phenomenon was also confirmed in the finite element analysis where a model for stress transfer along a crack obtained experimentally under uni-axial tension- compression cyclic loading was implemented.