Proctor Test and Subbase Analysis

When standing on a well graded aggregate there are a few things you want to check for proper compaction.

1. Dig down 6’’ through the aggregate and make sure you have an adequate depth. See proctor test details below for depth analysis.

2. Check for proper moisture. Dig down in several spots and squeeze the soil in your hand to make sure it sticks together. This is important to check when you are performing compaction with a rammer and/or plate compactor. The soil moisture should be even and at a optimum level.

3. Make sure there is no imperfections in the subbase greater than +_3/8th inch and 10 feet. Do this by using a rake with the teeth facing up. Scrap the rack against the surface looking for imperfections in the soil. Fill in some low spots and take out high spots until the surface has a nice even level for asphalt or concrete pouring.

4. Once this has been accomplished, you are ready to use your jumping jack rammer, vibratory plate, or reverse vibratory plate and start compaction. Always start with the perimeter and continue until you reach the center. Keep compacting until you pass your compaction test and reach the depth specified. Remember, after compaction begins communicate with your team to fill in the spots that are uneven to speed up the process.

Proctor Test

Compaction is the process by which the bulk of an aggregate/ soil matter is increased by driving out air. A proctor test helps achieve the optimum compaction. A proctor test can be done digitally or manually but it essentially is used to test the density of the soil. For the standard proctor test, use a cone full of soil from the site and then use a weight and perform 25 standard drop weights from 1ft high. After finishing the test, perform more tests with 4 different moisture contents. This will help you understand the soil : moisture ratio to achieve a proctor test of 95% density.

When you are in the field, using a nuclear gauge is ideal for measuring how well a compaction job was performed with your equipment. If a 95% compaction ratio is needed, you can test several areas of the soil to see if it meets this ratio or if further passes are need.  Understanding your soil:moisture ratio in your area is essential to getting proper compaction and also completing the job faster. With the right proctor test, soil:moisture ratio, and Tomahawk Power compaction equipment almost any job can be performed correctly.