ABSTRACT
Abstract This paper will present several two-and three-dimensional micromechanical models for describing the tension softening response of plain concrete. It will be shown that the rela tionship between the residual stress transfer capability and the crack opening displacement depends on only the fracture toughness of the matrix material (i.e. cement mortar) and the volume fraction of the stiff second phase (i.e. coarse aggregate). The models can therefore also describe the tension softening behaviour of any quasi-brittle material. The tension softening diagrams are useful not only in studying the fracture process in plain concrete but also in investigating the bond stress transfer from a reinforcing bar to surrounding concrete in reinforced concrete beams. A method for the splitting failure of reinforced concrete beams will be briefly presented and shown to be quite insensitive to the shape of the tension softening diagram. The latter may however play an important role, if the beam is submerged in water. Keywords: Tension Softening, Plain Concrete, Bond Stress, Reinforced Concrete, Beams, Splitting Failure.
