Determination of the bilinear stress-crack opening curve for normal- and high-strength concrete

187-SOC to determine the fracture parameters of concrete is applied in this study to several mixtures of normal and high-strength concretes. The results are processed with a C + + program developed by the authors to automatise the mathematical operations required to obtain the bilinear softening curve of concrete from the experimental results. Numerical simulations of the tests are also carried out using finite elements with an embedded cohesive crack. The comparison between numerical and experimental results confirms that the experimental and numerical procedures are appropiate for normal-strength concretes and high-strength concretes. Keywords cohesive crack; concrete; finite elements; fracture; high-strength concrete. NOMENCLATURE Em = average elasticity modulus /p = net plastic flexural resistance / p m = average net plastic flexural resistance ft = tensile strength /tm = average tensile strength fxs = indirect tensile strengt