A blast protective barrier system, termed a blast wall, providing a security perimeter or boundary at and above a ground level definable in terms of an x, y, z coordinate system, includes several substantially ground level (xy plane) pile caps, each itself having a y-axis elongate length, a x-axis width, and a z-axis depth, the x-axis substantially defining the width of the barrier system. Each pile cap also includes an upper and lower xy plane surface, each of the upper surfaces including y-axis channels and each of the lower surfaces including several recesses. The system also includes a first, second and further modules having a plurality of opposing pairs of yz plane, the y-axis elongate concrete panels including opposing integral xz end cap elements having a high shock-absorptive structure for isolating each module from the effect of a blast upon an adjacent module.