steel pans that were spray coated with a polyurethane compound that is extremely abrasion resistant a fourth slab was finished with ceramic impregnated uhmwpe pans and mounted beneath a reduced diameter steel backing disc i e 15 of the diameter of the plastic pan which used to support the curvature of the pan the urethane coated pans used for finishing the third slab failed quickly the coating deteriorated and large segments of it very rapidly peeled off after a brief delay the same trowel used on the fourth slab finished the third slab on dec 11 2002 at paragould ark three six inch thick concrete slabs were laid directly on a graded dirt base completely covered with polyethylene sheeting the concrete was air entrained without calcium additives the slabs were finished with dual pan power rider trowels driving the three types of float pans as discussed in example 3 three pan designs were used the pans were the same ones used in previous tests to further study the abrasion resistance and durability of plastic pans observed results were as follows the first slab which was finished with normal steel pans exhibited extensive delamination the third slab which was finished with uhmwpe pans had no observable delamination we determined that the.