Blow-ups refer to concrete pavement distress resulting from compressive failure at joints or cracks when excessive concrete pavement expansion occurs. The main cause of concrete pave- ment blow-up is the accumulation of axial compressive forces that are attributable to the expansion of concrete pavement. Several blow-up models have been proposed in previous research; it was practically impossible to validate the blow-up model because obtaining blow-up field data from pavements in service was not feasible. In other words, the period and location of their occurrence could not easily be predicted. Therefore, this study investi- gated the axial compressive forces and compressive stresses at the failure of blow-ups in con- crete pavement slabs using large-scale blow-up tests. Two concrete slabs were brought into contact, and horizontal compressive loads were applied to the ends of the slabs to determine when compressive failure occurred. An initial geometric imperfection range of 5–50 mm was set as the experimental condition. The test results showed that increasing initial geometric imperfections significantly reduced the compressive stress that caused compressive failure. Compressive failure occurred at approximately 53.0 % of the compressive strength when an initial geometric imperfection of 5 mm, which is the typical value attributable to curling and warping for concrete pavements, was observed. It was determined that the blow-up prediction could be improved based on the large-scale blow-up tests.