No! Aluminum reacts with the alkalis (OH) found in Portland cement concrete. When these two chemicals are combined, the reaction produces hydrogen gas. So concrete, when in direct contact with aluminum, creates a caustic reaction that will degrade the bottom of the tank and make it lose its vacuum. You should always use a cardboard or wood barrier between your tank and a concrete floor. Ideally, store your tank on a wood or fiber pallet in a cardboard box for maximum protection.