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ASTM C117: Materials Finer than 75-μm (No. 200) Sieve in Mineral Aggregates by Washing
The wash test that measures the clay, silt, and dust clinging to aggregate — fines that a dry sieve misses and that drive water demand, bond, and durability problems in concrete and asphalt.
| Designation | ASTM C117 |
| Setting | Laboratory |
| Service line | Construction Materials Testing |
Testing is performed to the current edition of ASTM C117 referenced by your project specification. This page is a plain-language overview, not a substitute for the published standard.
What the ASTM C117 test measures
ASTM C117 measures the amount of material finer than the No. 200 sieve in an aggregate by washing it over that sieve. Dust of fracture, silt, and clay coat the larger particles and cling in clumps that a dry sieve will not separate; water does. The loss in mass after washing and drying is the minus-200 content, reported as a percentage.
This test is the one that catches dirty aggregate. Excess fines raise water demand in concrete, weaken the paste-aggregate bond, cause plastic shrinkage cracking, and strip asphalt binder off the stone.
How the ASTM C117 test works, step by step
A representative sample is oven dried and weighed. It is covered with water, agitated to suspend the fines, and the wash water decanted through a nested No. 16 and No. 200 sieve. The cycle repeats until the wash water runs clear. Material retained on the sieves is returned to the sample, oven dried, and weighed again. The difference is the material that washed through.
A wetting agent may be used where clay coatings resist plain water; the report notes which procedure was followed. C117 is normally run before ASTM C136 so the dry sieve analysis can be corrected for the washed-out fines.
What the numbers mean
Concrete fine aggregate under ASTM C33 is generally limited to 3 percent minus 200 for concrete subject to abrasion and 5 percent otherwise, with higher limits allowed if the fines are dust of fracture rather than clay. Coarse aggregate is typically limited to 1 percent. Base course and asphalt specifications carry their own bands, and a jump in minus-200 over time is the classic sign a pit is working into a dirtier seam.
What can throw the result off
Losing material during decanting, not washing to clear water, and testing a sample that was not fully dried before the initial weighing are the usual errors. The companion determination of clay lumps and friable particles is a separate test, ASTM C142.
Common questions about ASTM C117
What is the difference between ASTM C117 and ASTM D1140?
The procedure is nearly identical. C117 is written for concrete and asphalt aggregate; D1140 is written for soils and is the one specified in earthwork.
Can I skip the wash and just dry sieve?
Not for acceptance. Dry sieving underreports fines, sometimes badly, on anything with clay coatings.
How we help with ASTM C117 testing
We run C117 ahead of every C136 gradation on concrete and base aggregate so the reported gradation reflects the true minus-200 content, and we track results by source so a trend toward dirtier material is flagged before it reaches your mix.
Scheduling & proposals
Need ASTM C117 testing?
Call for same-day dispatch questions, or send project documents for a written proposal.