Pre-Construction Testing
| What is being tested? | Name and/or descript of test | Required, Recommended, or Optional |
| Penetration |
A sand penetration test was developed by the Pennsylvania Department of Transportation (PennDOT) for dust suppressants. In this test, a sample of a silica sand is dried, then moisture is added to a level of 1.5 percent by mass. A small sample of this sand is placed in an 8 oz. ointment can and it is compacted to 100 psi by a flat-sided plunger. Subsequently, a sample of 5 grams of the prime coat material is poured in the center of the container and allowed to flow by itself. The time is measured, in seconds, for the liquid to completely penetrate into the compacted sand. After penetration is complete, the sand bed is cut in half with a spatula and the average penetration depth of the liquid is measured and recorded. |
Recommended |
If the penetration of the material is not sufficient, scarification of the surface may be required to mix in the prime coat material. Please refer to Process for Mixing Grade Emulsions.
Construction Testing
| What is being tested? | Name and/or descript of test | Required, Recommended, or Optional |
| Penetration | Locate three or more representative areas. • After prime has cured sufficiently so that the surface is no longer tacky (at least one hour after prime coat application), make two 2 inch vertical slices into the base course using chisel and hammer, approximately 1 inch apart. A piece of base will usually debond. If no debonding occurs, retry with less separation. • Clean area between the two cuts taking special care when removing large aggregates. • Sweep cut area using a small whisk broom, sweeping from bottom to top and center to edge. • Measure penetration depths at each location (brown color) using a ruler and compute average. |
Recommended |
Post-Construction Testing
Based on a worldwide review of the literature there are no standardized tests that objectively measure prime coat quality.
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