Grain Size Analysis for Foundation Design in Billings

For a standard ASTM D422 test with full sieve stack and hydrometer sedimentation, the cost ranges from US$110 to US$180 per sample depending on the number of samples in the batch and whether Atterberg limits are included in the same request.

Minimum 24 hours for the sedimentation readings alone. The full report—including sieve analysis, hydrometer, curve plotting, and USCS classification—is typically delivered within 3 to 4 business days from sample receipt. We can expedite to 48 hours for tight project schedules.

Yes. The gradation curve and USCS group symbol tell you whether the material is well-graded gravel (GW), poorly-graded sand (SP), silty sand (SM), or lean clay (CL). That classification directly determines the appropriate compaction method, moisture conditioning requirements, and density targets per your project spec.

We need roughly 500 grams of material passing the #4 sieve for the hydrometer. For the full sieve stack, the total sample depends on maximum particle size: about 500 g for fine sands, up to 5 kg for gravelly soils with particles up to 3 inches. We can advise on sample splitting if you are pulling from a larger bulk sample.

Grain size alone only tells you the clay fraction percentage—the minus 2-micron content. To confirm expansive behavior, you need the Atterberg limits (liquid limit and plasticity index) and ideally a swell test. We offer all three as a combined package when expansive soils are a concern in the Billings area.