Diagnosing Soil Compaction Using a Penetrometer (Soil Compaction Tester) A diagnostic tool to measure the extent and depth of subsurface compaction is a penetrometer, or soil compaction tester.
How do you test the compaction of soil at a site?
Dry density is calculated by dividing the weight of the wet soil by its water content in percent. The percent compaction for the field density test is calculated by dividing the dry density of the soil by the maximum dry density from the proctor test.
How do you find the compaction factor of soil?
Divide the weight of the dry soil by the volume of sand required to fill the hole to find the soil density in pounds per cubic foot. For example, if the weight of the soil is now 1 lb. and the volume of the sand in the hole is . 5 cubic feet, the density would be 1 lb/.
How does a soil compaction meter work?
Soil Compaction meters (often called penetrometers) are used to determine the density of soil and other material. An operator pushes a rod with attached (ASAE standard) cone into the ground. The resistance of the cone is displayed as it is pushed in the ground.
How do you perform a compaction test?
To begin, a small hole is dug in the compacted soil. This soil is removed and weighed, then dried and weighed again to determine the moisture content. The hole’s specific volume is measured by filling it with a pre-calculated amount of dry sand from a jar and cone device.
How do you test for compaction?
To check deeper for resistance or compacted layers, insert a soil probe, tile probe or even the wire of a marking flag slowly into the soil in several areas of the field, feeling the force needed to push into the soil and recording the depths where you feel resistance or where the flag wire starts to bend.
How do you conduct a compaction test?
The procedure of the Proctor Compaction Test consists of the following steps:
- Obtain about 3 kg of soil.
- Pass the soil through the No.
- Weight the soil mass and the mold without the collar (Wm).
- Place the soil in the mixer and gradually add water to reach the desired moisture content (w).
- Apply lubricant to the collar.
How is compaction testing done?
After excavation a field technician will collect soil samples. Once the soil is prepped the soil will go into a cylindrical mold to be compacted at various moisture contents and weighted. The test is to see how much of the material can be compacted into the same volume at the various amounts of moisture.
How much does gravel shrink when compacted?
Result
| Material | Swell/Bulking % | Shrink % |
|---|---|---|
| Gravel | 5 | -3 |
| Gravel, Average Graduation, Dry | 15 | -7 |
| Gravel, Average Graduation, Wet | 5 | -3 |
| Gravel, Dry | 15 | -7 |
How do you find the degree of compaction?
Degree of compaction = Field dry density / maximum dry density determined in the laboratory. For non-cohesive soil, it is some times called density index.
How much does a soil compaction test cost?
Soil Compaction Test Cost The soil compaction test costs about $100 to $125 per testing location. The number of locations will depend on the size of the property and if there are different areas with multiple types of soil.
How do you use a penetrometer to measure soil compaction?
As you push the penetrometer into the soil, record the depth at which the 300 psi level is exceeded, using the gradients on the penetrometer rod. This level is the top of the compacted zone. Continue pressing the penetrometer down. Record the depth at which the penetration falls below 300 psi. This is the bottom of the compacted zone.
Do you have a subsurface compaction problem in Pennsylvania?
Many Pennsylvania producers suspect they have a subsurface compaction problem, but have no handle on how to measure it. A diagnostic tool to measure the extent and depth of subsurface compaction is a penetrometer, or soil compaction tester.
What are the four types of compaction effort on soil?
There are four types of compaction effort on soil or asphalt: ■Vibration ■Impact ■Kneading ■Pressure Soil Compaction Soil compaction is defined as the method of mechanically increasing the density of soil. In construction, this is a significant part of the building process.
How do you know if soil has enough moisture for compaction?
If the soil is moldable and breaks into only a couple of pieces when dropped, it has the right amount of moisture for proper compaction. If the soil is plastic in your hand, leaves small traces of moisture on your fingers and stays in one piece when dropped, it has too much moisture for compaction.
