Ideal for pouring concrete slabs and setting posts. 4000 psi average compressive concrete strength. Concrete Mix is ideal for both structural and non structural applications over 2 in. This ready to use product contains a blend of Portland cement, sand, gravel, and other approved ingredients. Concrete Mix is perfect for projects requiring a quality, general use concrete mix.Ideal for sidewalks, steps, walkways, foundations, footings, and other general concrete work. Perfect for setting mailbox posts, fence posts, and lamp posts. Meets ASTM C 387 compressive strength requirements. Note: product may vary by store.