| AASHTO CLASS | Description | Comments / Recommendation | Unified Group |
|---|---|---|---|
| A-1-a | WELL GRADED GRAVEL AND GRAVEL MIXTURES. LITTLE OR NO FINES. | ADD FINES:COMBINE WITH SM / SC / ML / CL / GL / MH / CH / OH | GW |
| A-1-a | POORLY GRADED GRAVEL AND GRAVEL / SAND MIXTURES. LITTLE OR NO FINES. |
ADD FINES. COMBINE WITH SM / SC / ML / CL / GL / MH / CH / OH |
GP |
| A-1-b | SILTY GRAVEL GRAVEL / SAND / SILT MIXTURES. |
OK – PROVIDED FINE CONTENT IS AT LEAST 20 PERCENT. COMBINE WITH SM / SC / ML / CL / GL / MH / CH / OH |
GM |
| A-1-b | CLAYEY GRAVEL/GRAVEL / SAND / SILT MIXTURES. | OK. | GC |
| A-1-b | WELL-GRADED SAND AND GRAVELLY SAND – LITTLE OR NO FINES. | ADD FINES.COMBINE WITH SM / SC / ML / CL / GL / MH / CH / OH | SW |
| A-1-b A-3 |
POORLY GRADED SAND AND GRAVELLY SAND – LITTLE OR NO FINES. | ADD FINES COMBINE WITH SM / SC / ML / CL / GL / MH / CH / OH |
SP |
| A-2-4 A-2-5 |
SILTY SAND, SAND-SILT MIXTURES. | OK. COMBINE WITH GW / GP / GM / GC | SM |
| A-2-6 A-2-7 |
CLAYEY SAND, SAND-CLAY MIXTURES. | OK. | SC |
| A-4 | INORGANIC SILT, VERY FINE SAND, ROCK FLOUR, SILTY OR CLAYEY FINE SANDS. | OK. COMBINE WITH GW / GP / GM / GC | ML |
| A-6 | INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, GRAVELLY CLAYS, SANDY CLAYS, SILTY CLAYS, LEAN CLAYS. | OK. | CL |
| A-4 | INORGANIC SILTS AND ORGANIC SILTY CLAYS OF LOW PLASTICITY. | OK. CONSULT W/ TXI | OL |
| A-5 | INORGANIC SILTS. | OK. CONSULT W/ TXI | MH |
| A-7-6 | INORGANIC CLAYS OF HIGH PLASTICITY. FAT CLAYS. | OK. CONSULT W/ TXI | CH |
| A-7-5 | ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY. | OK. CONSULT W/ TXI | OH |
| A-8 | PEAT, MUCK AND OTHER HIGHLY ORGANIC SOILS. | COMBINE WITH SM / SC / ML / CL / GL / MH / CH / OH | PT |