Pavement strength is defined as the maximum stress that leads to crack initialization in a concrete pavement. Full-scale static step-loads were applied at the free edge of concrete slabs to induce bottom-up and top-down cracks, and then to determine the pavement strength. Both top-down and bottom-up crack initializations were successfully detected. Then the pavement strength was estimated using the collected test data and two assumptions: the pavement strength is similar at the slab top and bottom, and the residual stress at the slab top and bottom has the same magnitude but different signs. It has been found that the laboratory flexural strength of the cast beam was higher than the pavement strength in full-scale tests, while the flexural strength of the saw-cut beams from the slabs was lower than it. © 2008 Taylor & Francis Group, London.