Seven alumni from the University of Arizona's mining and geological engineering program competed in the alumni division, coming in second place. The competition commemorates the 91 miners who died in the 1972 Sunshine mine disaster and continues to honor all miners who have lost their lives while on the job.
Place concrete at a minimum thickness of 4 inches. Increasing the thickness from 4 inches to 5 inches will add approximately 20% to your concrete cost, but will also boost your driveway's load-carrying capacity nearly 50% , according to the Tennessee Concrete Association.lace concrete at a minimum thickness of 4 inches. Increasing the thickness from 4 inches to 5 inches will add approximately 20% to your concrete cost, but will also boost your driveway's load-carrying capacity nearly 50% , according to the Tennessee Concrete Association.
1 Order concrete with a compressive strength that meets your needs. 2  Make sure the aggregate is appropriate to the thickness of the slab you are pouring. 3  Order the mix with a Plasticizer or a Super Plasticizer, and make sure that the water:cement ratio is not over .55:1.trength: Most contractors know that they can specify the STRENGTH of the concrete. Strength of concrete is measured in PSI, or Pounds per Square Inch (or MPa, MegaPascals, the metric version of PSI). A normal strength of concrete for residential driveways is between 3000 and 4000psi (20 â 27 MPa).