Steel-concrete composite sandwich panels are used in blast doors and walls to protect personnel and equipment in explosive environments due to their superior performance against blast effects. In the design of such panels, most design methods treat blast and fragment loading independently for far-field scaled distances. However, in close-in explosion scenarios, there is a need to consider the synergistic effects of combined loading from blast and fragments. In this study, an explosive field test program was conducted to assess the damage and the structural response to the steel-concrete composite panels subjected to close-in explosion of cased charges at scaled distance between 0.41 to 0.82 m/kg1/3. The test program included characterization test for the cased charge to determine the blast overpressure profile, fragment mass and velocity. Numerical simulations using high-fidelity physics based finite element analysis technique were used to model the structural response to the combined loading. The validation of the numerical model was conducted using the experimental field blast test data.