Field Density Test Report
[ Method: Sand Replacement (IS 2720 Part-28) ]
| Parameter | Sample 1 | Sample 2 | Sample 3 |
|---|---|---|---|
| MDD (gm/cc) | |||
| Bulk Density Sand | |||
| Offset / Chainage | |||
| FIELD DATA | |||
| Wt. Wet Material (Ww) | |||
| Sand+Cyl Before (W1) | |||
| Sand+Cyl After (W2) | |||
| Sand in Cone (W3) | |||
| Sand in Hole (W4) | |||
| Volume Hole (V) cc | |||
| Bulk Density (Ýb) | |||
| MOISTURE CONTENT | |||
| Moisture Content (%) | |||
| RESULTS | |||
| Field Dry Density (Ýd) | |||
| Compaction % | |||
Technical Guide: Field Density Test (Sand Replacement)
The **Field Density Test (FDT)** by Sand Replacement Method is a standard test to determine the in-situ dry density of soil. It is critical for road embankments, canal linings, and structural backfilling.
1. Standard Reference
2. Apparatus Required
- Sand Pouring Cylinder: (Large or Small depending on soil type).
- Cylindrical Calibration Container: To check sand density.
- Tray with Central Hole: For excavation guide.
- Standard Sand: Clean sand passing 1.0mm sieve and retained on 600 micron sieve.
3. Procedure Overview
1. Calibration: First, determine the bulk density of the sand ($\gamma_s$) and weight of sand in the cone ($W_3$).
2. Excavation: Dig a hole at the test spot through the tray. Collect all excavated soil and weigh it ($W_w$).
3. Sand Pouring: Place the cylinder (Weight $W_1$) over the hole. Open shutter to fill hole and cone with sand. Weigh remaining cylinder ($W_2$).
4. Calculation: Calculate volume of hole ($V$) based on weight of sand consumed ($W_1 - W_2 - W_3$).
4. Calculations & Formulas
- Bulk Density ($\gamma_b$): $Weight_{Soil} / Volume_{Hole}$
- Dry Density ($\gamma_d$): $\gamma_b / (1 + \frac{w}{100})$ where $w$ is moisture content %.
- Compaction (%): $(\gamma_d / MDD) \times 100$
5. Acceptance Criteria
As per MORTH specifications, a set of tests is accepted if:
Mean Density $\ge$ Specified Density + [1.65 - 1.65 / $\sqrt{N}$] $\times$ Standard Deviation