Paver Pete demonstrates how to pre-plan a driveway installation, perform an excavation and add a chemical amendment.
Paver Pete explains how to pre-plan your jobs and soil analysis.
Pre-planning a job and analyzing the soils can save you time and money.
In this case, we dug a hole for our test a couple of weeks prior.
By sending soil samples to a lab, we received the data that allowed us to design this driveway with a thinner base, from 24 inches to 12 inches.
Contrary to what some people might think, the thickness of a base can’t be increased without compaction or using a geotextile fabric.
A subgrade needs to be classified and compacted.
STEP 1: Amend the subgrade.
In this case, we have a weak clay subgrade, so we used a type-S mortar mix for a chemical amendment. We also added a gradation amendment, ¾-inch clean stone, to increase its bearing ability.
STEP 2: Compact the subgrade.
We used a 13,500-pound centrifugal force rated vibratory plate compactor and incorporated both amendments into the subgrade.
STEP 3: Add a geotextile with biaxial geogrid strength
STEP 4: Build the 12-inch base.
Paver Pete lists possible costs related to excavation on a driveway project.
Here are some important costs related to the excavated material:
- Truck and driver
- Distance to the dumpsite
- Soil analysis fee at the dumpsite for presence of contaminants, petroleum and heavy metals
By analyzing the soil and switching from a 24-inches base to a 12-inch base, the quantity of soil excavated diminishes and allows us to save a lot of money.
Paver Pete explains why the current aggregate base should be removed.
In this case, an aggregate base had previously been installed.
The previous builders had told these homeowners to leave the base in for one year and it would naturally settle in and compact itself, than a driveway could be installed.
Now, it needs to be removed for the following reasons :
- The subgrade has not been classified and compacted
- No geotextile fabric has been installed
- Current level of compaction is probably not optimal.
Adding a chemical amendment
Paver Pete demonstrates how to add a chemical amendment.
A granular amendment has been applied to the subgrade.
A chemical amendment needs to be added to it since it rained a lot in the previous weeks.
We chose a type S mortar mix.
We spreaded a 50-pound bag for a hundred square feet.
The product changes the chemistry of the clay, opening it up and drying it out.