What Is Field Density Test?

Different Types of Field Density Tests

1. Sand Cone Method or Sand Replacement Method
2. Water Replacement Method of Field Density Test
3. Core Cutter method
4. Heavy oil Method
5. Rubber Balloon Method
6. Nuclear Moisture Density Meter

#1. Sand Replacement Method or Sand Cone Method-

Apparatus

• Sand – pouring cylinder
• Excavating tools, and Soil cutting such as scrapper tool bent spoon
• Calibrating container, 100mm diameter, and 150mm height
• Plane surface: Perspex Plate or Glass or Other Plane Surface, 450mm square, 9mm thick or larger
• A metal container to collect excavated soil
• Weighing balance accurate to 1 gram
• Metal tray, 40 mm deep and 300mm square with a hole of 100mm in diameter at the center
• Weighing balance accurate to 1 gram
• Moisture content cans
• Oven

Calibrations of Instrument.

1. Measure the internal dimensions of this calibrating container and calculate its volume.
2. Fill the sand-pouring cylinder with sand, in about dia 10mm of its top. Dia the weight of the filled cylinder (M1).
3. Place the sand-pouring cylinder vertically onto the calibrating container. Open the shutter to allow the sand to run out of the cylinder. When there isn't any further movement of the sand in the cylinder, close the shutter.
4. Lift the pouring cylinder from the calibrating container and weigh it into the nearest gram (M2).
5. Place the sand pouring cylinder on the glass plate. Open the shutter and allow the sand to run from the cylinder until no further movement of the sand will be noticed (sand fills the Cone of the cylinder), then close the shutter and remove the sand-pouring cylinder carefully.
6. Take the sand onto the glass plate and determine its weight (M3)
7. Repeat step 3 to step 6 two more times, and record mean weight (mean M3 and M2)
8. Determine the Filed dry Density of sand, as shown in the below Table.

Calibration for Dry Density of Sand - Table 

Procedure of Sand Replacement Method

1. Expose an area of about 450mm square on the top layer of the soil mass. Trim the surface down to a level surface using a scraper tool.
2. Place the metal tray on the leveled surface.
3. Excavate the soil through the central hole of the tray, using the hole in the tray as a pattern. The depth of the excavated hole must be about 150mm.
4. Collect all the excavated soil in a metal container and determine the mass of the soil (M).
5. Remove the metal tray in the excavated hole.
6. Fill the sand pouring cylinder within 10mm of its top. Determine its mass (M1).
7. Place the cylinder directly over the excavated hole. Allow the sand to run out of the cylinder by opening the shutter. Close the shutter when the hole is completely filled, and no further movement of sand is observed.
8. Remove the cylinder from the filled hole. Determine the mass of the cylinder (M4).
9. Take a representative sample of the excavated soil. Determine its water content.
10. Determine the dry density of soil, as shown in Below Table.

#2. Water Replacement Method-

Apparatus of Water Replacement Method:

• Water displacement apparatus
• Weighing balance, accuracy 1g.
• Paraffin wax (density of paraffin (Pp)= 0.91 g/ml).
• Cutting knife
• Brush
• Water content container
• Heater
• Oven
• Measuring jar

The Procedure of Water Replacement Method of Field Density Test

1. Take the soil specimen.
2. Trim it to a regular shape. Avoid re-entrant corners. Weigh the specimen.
3. Take a paraffin wax and melt it onto a heater. Apply a coating of melted paraffin wax into the specimen with a brush. When it's hardened, apply another coat. Take the mass of this waxed specimen (Mt).
4. Fill the water displacement apparatus with water. After the flow occurs, close the valve.
5. Place a measuring jar below the overflow tube of the apparatus. Open valve.
6. Immerse the waxed specimen slowly into the water from the apparatus. Water overflows. Collect the overflowed water from the jar. Determine the volume of the water collected (Vt).
7. Take out the waxed specimen from the apparatus. Dry it from outside.
8. Remove the paraffin wax by peeling off it.
9. Cut the specimen into two pieces. Take a representative sample for the water content determination.

Calculations Sheet of Water Replacement Method:

#3. Core Cutter Method:

#4. Rubber Balloon Method:

Apparatus Required

1. Balloon Density Meter
2. Soil augur or trowel
3. Moisture tight container
4. Weight balance
5. Rubber bulb pump
6. Density plate with fasteners
7. Rubber balloons
8. Drying Oven

The Procedure of the Rubber Balloon Method

1. Position the density plate on a flat surface and set the volume measuring (A) apparatus in the recessed hole in the density plate
2. Hold the apparatus down firmly in position, open the control valve, pump the balloon down with the rubber bulb until the water level in the graduated cylinder has reached its lowest position, and record this volume, which is the initial reading.
3. Pump the balloon back into the cylinder by inverting the rubber bulb, and close the control valve.
4. Place the density plate in a level position on the material to be tested, dig a test hole about4 in diameter, and 4 in. Deep, retain all the material which is removed from the hole, then measure and record the mass of the excavated soil.
5. Set the apparatus in the recess in the density plate, hold it down firmly, open the control valve, pump the balloon into the hole, and record the lowest point reached by the water in-cylinder, which is the final reading.
6. Invert the pressure-vacuum bulb and pump the balloon back into the cylinder.
7. Subtract the initial reading from the final reading and obtain the volume of the hole in cubic feet.
8. Mix the material thoroughly and secure a representative sample of not less than 100 gm for moisture determination.
9. Make density calculations based on the volume of the test hole and dry or wet weight (as required) of materials removed.

Calculation of Rubber Balloon Method

• Calculate the moisture content, w (expressed as a percentage of the weight of the dry soil), of the soil as follows:
• w = weight of dry soil x 100%
• Calculate the volume, wet and dry density of the soil as follows
• V = V2 – V1

#5. Nuclear Moisture Density Meter

Apparatus Required

• Portable Nuclear Moisture-Density Gauge
• Transport case (Type “A” Package)
• Charger
• Reference Standard Block
• Transport Documents (Bill of Lading)
• Leveling Plate/Drill Rod Guide
• Drill Rod w/extraction tool
• Hammer (4 lbs.) used for Driving the Pin
• Safety Glasses
• Square-Point Shovel
• No. 4 sieve
• Set Balance Scales
• Drying Apparatus
• Miscellaneous Tools like Mixing Pans and Spoons

The Procedure of Nuclear Moisture Density Meter

Roller Pattern

Listed Below are the Steps Used to Construct a Roller Pattern:

Obtain Total and Average for Both Moisture and Density.

• Compaction equipment
• The visual change in subsurface conditions
• Test section readings are significantly above the target values by more than 8 lb/feet3
• Another Control Strip will be established.
• Gradation or types of material
• Nuclear Density Gauge

FDT Test:

Sand Replacement Method:

What Is Sand Replacement Method?

What Is Sand Cone Method?

Water Replacement Method-

Heavy Oil Method in Field Density Test-

What Is Rubber Balloon Method?

Nuclear Moisture Density Meter.

What Is Nuclear Moisture Density Meter?

Field Dry Density Test Procedure

• First, take the weight of the empty sand cone and then fill it with dry sand and then weigh again.
• Collect the excavated soil from the hole and measure the weight.
• After weighting, collect the specimen of soil to determine the water content in it.

Field Dry Density Test Equipment

1. Sand Cone Test Apparatus: This apparatus consists of a sand cone with a valve, a base plate, and a container to collect the excavated soil. It is used to measure the volume of soil in place.
2. Moisture Content Determination Equipment: This can include a moisture content balance or oven for determining the moisture content of the soil sample.
3. Core Cutter: A cylindrical steel or brass cutter with a cutting edge is used to extract undisturbed soil samples from the field.

Field Dry Density Test Calculation

Field Dry Density Test Standards

Importance of Field Dry Density Test

Fdd Full Form in Civil Engineering

Fdd Test Full Form

What Is Field Density?

What Is Fdt Test?

What Is Field Density of Soil?

Field Dry Density Test

Dry Bulk Density Formula

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