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Scope

This procedure is intended for using OPF42 as an alternative to stone as a base course in concrete and asphalt paving projects. OPF42 is handled like crushed limestone.

Procedure

1. Spread OPF42 over the desired area using suitable equipment.

2. Bring the OPF42 to its optimum moisture content as pre-determined using the Standard Test Method for Laboratory Compaction Characteristics of Soil Using Standard Effort (12,400 ft-lbf/ft3 (600 kN-m/m3))--American Society for Testing and Materials (ASTM) D698.

3. Compact the material to the required density. Each compacted layer should not exceed eight inches thickness. Unlike limestone, attempts to achieve further compaction after the initial 3 to 4 days curing period should be avoided. Compaction attempts after the initial cure period may lead to fracture or laminations.

4. The surface may be fine bladed (clipped) even after the initial cure period to achieve the final grade. The final surface should be primed with a suitable emulsion to form a moisture barrierprior to paving.

5. As with most base material, significant rainfall on the material within several days after installation may cause weak or failed areas. Proof rolling prior to further construction is recommended.

Testing

Nuclear density testing should be approached with the same precautions used for lime and cement. Nuclear probes measure hydrogen usually in the form of water. Because materials like lime, fly ash, cement, gypsum, OPF42 contain naturally occurring hydrogen or bound hydrogen, the probe may give falsely high readings. Oven dried moisture samples may be required to correct the nuclear moisture readings. These samples should be dried in an oven at a temperature not greater than 140 degrees Fahrenheit (60 degrees Celcius) until a constant weight is obtained. Corrections can then be made to the moisture content as directed by the nuclear device manufacturer's instructions.