A thermal barrier panel, the panel having a top face overlying a monolithic core, the core comprising a mixture of expanded glass granules, ceramic microspheres and a calcium aluminate cement binder, the expanded glass granules are selected from the group consisting of small granules having a size of about 0.5 mm to 1.0 mm, intermediate granules having a size of about 1.10 mm to 2.00 mm, and large granules having a size of about 2.10 mm to 4.00 mm wherein the volume of intermediate size granules comprises more than 50% of the mixture of expanded glass granules and the balance comprises small and large granules in a ratio of 1:2. The invention is also directed to a shipping container fitted with the fire containment panels of the present invention.