Compaction tests · Field density test · ASTM D1556
Sand Cone and Proctor Compaction Test
We measure in-situ density with the sand cone on fill, road sub-base and controlled fill under buildings. Following ASTM D1556 we find the volume of the hole with calibrated sand, divide the dry density by the Proctor value and report the degree of compaction.
Call us directly: +90 533 616 18 67
- ASTM D1556 · AASHTO T191
- No radioactive source
- Cross-check with the nuclear gauge
- Since 2001 on site
- Jar filled with calibrated sand
- Valve
- Cone
- Base plate with a hole
- Test hole, filled with sand
- Soil from the hole is weighed
Definition
What is the sand cone test?
The sand cone test is a field test in which a small hole is dug in compacted soil, the soil removed is weighed and the volume of the hole is found with calibrated sand of known unit weight. Dividing the mass of the soil by its volume gives the in-situ density. It is also known as the sand replacement or field density test.
The dry density is divided by the maximum dry density of the same material from the Proctor test to give the degree of compaction. Fill is usually required to reach 95%; the value is set by the project specification.
It uses no radioactive source, so no licence is needed. It is used on materials unsuitable for the nuclear density test and to verify nuclear results.
Proctor test: the laboratory test that gives the optimum moisture content at which a soil reaches its maximum dry density. The standard Proctor test compacts 4–6 samples, each at a different moisture content, in three layers of 25 blows in a 4-inch mould with a 5.5 lb hammer dropped 12 inches; the modified Proctor test uses a higher compaction energy. We take the samples; the tests are carried out in an accredited laboratory.
At a glance
| Standards | ASTM D1556, AASHTO T191, BS 1377-9. |
|---|---|
| Measured value | In-situ wet and dry density, % Proctor. |
| Hole | About 15 cm in diameter through the base plate hole, as deep as the layer thickness. |
| Sand | Clean, dry, free-flowing sand with calibrated unit weight. |
| Moisture content | Found by oven-drying the soil from the hole. |
| Prerequisite | A Proctor test of the material carried out in an accredited laboratory. |
When to choose it
Strengths and limits of the sand cone
Strengths
- Direct measurement: mass and volume are weighed
- No radioactive source, licence or dosimetry needed
- The reference method for verifying nuclear gauge results
- Can be used on materials unsuitable for the nuclear gauge
- Simple equipment that can be carried to any site
Points to watch
- Takes longer than the nuclear test; the final result comes after oven-drying
- Cannot be used in saturated soils or soils that flow or collapse when the hole is dug
- In soft soils that deform easily the hole volume is distorted
- Very coarse-grained fills need a larger-scale method
- Vibrating plant working nearby disturbs the sand and must be stopped during the test
On site
How is the sand cone test carried out?
- The sand and cone are calibratedThe unit weight of the sand and the amount of sand that fills the cone are found before the test.
- The surface is preparedThe test point is levelled, loose material is removed and the base plate is fixed to the surface.
- The hole is dugA hole as deep as the layer thickness is dug through the plate. All the soil removed is placed in a sealed container so none is lost.
- The hole is filled with sandThe full jar is weighed, the cone is seated on the plate and the valve is opened. When the sand stops flowing the valve is closed and the jar is weighed again.
- The soil is weighed and driedThe wet soil from the hole is weighed. A sample is oven-dried for the moisture content.
- Calculated and reportedHole volume, wet and dry density and degree of compaction are calculated, assessed against the specification and reported.
Calculating the results
How is the degree of compaction calculated in the sand cone test?
The starting values are an example. Enter your own measurements and the calculation updates step by step.
- Sand in the holebefore − after − cone
- Hole volume Vsand in the hole / unit weight of the sand
- Wet density γnwet soil / V
- Dry density γdγn / (1 + w)
- Compactionγd / γd,max × 100
Price
Sand cone test price
The price depends mainly on the number of points and the project location.
- The more points, the lower the price per point
- If no Proctor test has been done, the accredited laboratory fee is added
- For many points, the nuclear test with sand cone checks in between is the most economical solution
- Travel and accommodation are added for sites outside Istanbul
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Before the test day
What we need on site
- The layer to be tested must be placed, compacted and levelled
- The Proctor test of the material must be done or a sample taken
- Rollers and vibrating plant nearby must stop during the test
- Test point locations, a sketch or chainage must be agreed
- Send us the specified compaction and test frequency, if any
After the test
What is in the report?
- Sand calibration and cone constant
- Weights, hole volume and moisture content for each point
- Wet and dry density, degree of compaction
- Pass or fail against the specification
- Test point locations and layer information
Applications
Where is the sand cone test used?
Projects where we have carried out compaction control include the TANAP pipeline, Istanbul Airport and TOKİ Silivri housing. See our references page for the full list.
Comparison
Sand cone or nuclear gauge?
| Sand cone | Nuclear density test | |
|---|---|---|
| Standard | ASTM D1556 | ASTM D6938 |
| Measurement | Direct, by weighing mass and volume | Indirect, by gamma and neutron counts |
| Moisture content | By oven-drying | Measured on site by the gauge |
| Result | After oven-drying | Immediately at the point |
| Licence | Not needed | NDK licence and operator with dosimeter |
| Best use | Verification, few points, materials unsuitable for the nuclear gauge | Fast checks at many points |
For many points the most efficient approach is fast checking with the nuclear gauge and verification with the sand cone at set intervals. Where the specification requires a modulus, a light weight deflectometer (LWD) or static plate load test is carried out.
Frequently asked questions
About the sand cone test
What is the sand cone test?
A field test in which a small hole is dug in compacted soil, the soil removed is weighed and the volume of the hole is found with calibrated sand. Dividing the mass of the soil by its volume gives the in-situ density; dividing by the Proctor value gives the degree of compaction.
Which standard is the sand cone test carried out to?
Mostly ASTM D1556. AASHTO T191 and BS 1377-9 describe the same method.
How is the sand cone test calculated?
The sand in the hole is the difference between the first and last jar weights minus the sand in the cone. Dividing this mass by the unit weight of the sand gives the hole volume. The wet soil from the hole is divided by the volume, the dry density is calculated from the moisture content, and dividing by the Proctor value gives the degree of compaction.
Is a Proctor test required for the sand cone?
Yes. The degree of compaction is the ratio of the field dry density to the maximum dry density from the Proctor test. A 10–15 kg sample is taken from the material and the Proctor test is carried out in an accredited laboratory.
What is the Proctor test?
A laboratory test that gives the optimum moisture content at which a soil reaches its maximum dry density. The standard Proctor test compacts 4–6 samples at different moisture contents in three layers of 25 blows; the modified Proctor test uses a higher compaction energy.
Which sand is used in the sand cone test?
Clean, dry, free-flowing sand with grains of similar size. Its unit weight is found by calibration before the test. The site soil itself is not used for this.
What degree of compaction is required for fill?
The acceptance value is set by the project specification. Fill is usually required to reach 95% of the Proctor value; the value depends on the position of the layer and the Proctor test used.
Sand cone or nuclear density test: which is better?
The sand cone is the reference method because it relies on direct weighing and needs no licence, but it takes longer. The nuclear test gives the result at the point immediately. For many points, testing with the nuclear gauge and verifying with the sand cone at intervals is the most efficient approach.
Where can the sand cone test not be used?
In saturated soils, soils that flow or collapse when the hole is dug, and soft soils that deform easily. Very coarse-grained fills need larger-scale methods.
When is the result available?
Hole volume and wet density are calculated on site. Because moisture content is found by oven-drying, the final dry density and degree of compaction come after drying.
How deep is the hole?
The hole is dug through the roughly 15 cm hole of the base plate, as deep as the layer being tested. Each compacted layer is therefore tested separately.
Let us verify the compaction of your fill on site
Send us the number of points, the type of work and the project location. We will have the Proctor test done in an accredited laboratory and plan the field measurements.
Sarıgöl Mah. Mezarlık Sk. C1 No: 108 İç Kapı No: 63
Gaziosmanpaşa, Istanbul, Turkey
Mobile / WhatsApp: +90 533 616 18 67
Phone: +90 212 369 00 16
info@zeminarastirma.com
Mon–Fri 08:00–19:00 · Sat–Sun 08:00–14:00 (GMT+3)