This specification covers concrete roof pavers that are machine-made from hydraulic cement, water, and suitable mineral aggregates with or without the inclusion of other materials, for use as roof ballast and protection of roof membranes. Requirements for ballast weight per unit area shall be specified separately. The average resistance to flexural load for three paver units and resistance to flexural load of each individual unit shall exceed the prescribed requirements. In areas where repeated freezing and thawing under saturated conditions occur, freeze-thaw durability shall be demonstrated by test or by proven field performance that the concrete roof paver units have adequate durability for the intended use. Minor cracks incidental to the usual method of manufacture or minor chipping resulting from customary methods of handling in shipment and delivery are not grounds for rejection. Compressive strength, flexural load, absorption, density, ballast weight, and dimensional tolerance shall be tested to meet the requirements prescribed.
