Beacon BallieldDimensionsGuide-2024-WEB - Flipbook - Page 38
INFIELD SOILS
Infield installation
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CONTINUED
4 Compaction of both subgrade and infield material.
Compaction involves removing pore space in a soil which increases
soil density and soil firmness. Compaction is important not only for
the infield material, but for the subgrade layer beneath it as well.
Maximum density/firmness are determined by the makeup of the
soil including the percentage of sand, silt, clay, and organic matter
present, as well as the mineralogy of the soil.
DuraEdge calls for their infield soil material to be optimally compacted
to 85-90% as achieved on a standard “Proctor” test (see below).
To accomplish this, the subgrade must be compacted to at least 90%
Proctor or higher. If compaction is less than 90%, the infield material
above it will struggle or even fail to achieve the required compaction
which can result in a faulty installation and poor infield performance.
If the existing subsoil is not able to achieve 90% compaction, remove
subsoil and replace with a granular fill of a 3/8" minus angular stone
product and compact. For the infield soil, a 4" profile should be
installed and compacted in layers up to 2" thick to ensure necessary
compaction throughout the profile. These layers are called “lifts”.
5 Don’t forget to add the “glue” — also known as water.
One of the key components for proper compaction of soil is moisture.
It is truly the “glue” that holds soil together. Water and scarification
help the compressed soil to bind and hold, which removes pore space.
If an infield soil is left too dry when the installer attempts to compact,
the soil simply will not bind.
The negative consequence of unbound soil will be apparent with the
first rain event on the new infield. It will quickly turn into a quagmire.
Inadequate compaction during installation due to a lack of moisture
allows the pore space to remain, which then fills with rainwater.
To prevent this scenario, during installation think, “Moisten. Scarify.
Add. Compact.” When you’re adding a new lift of soil, be sure to
moisten the soil that you are adding to, then scarify that surface
before adding the next lift and compacting with a roller.
The Proctor compaction test is a laboratory method of experimentally
determining the optimal moisture content at which a given soil type will
become its most dense and achieve its maximum dry density (compaction).
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The one caveat is to not over water the soil. The goal is enough
water to permeate through the entire soil layer, but not so much
that it becomes saturated, fills all the pore space and pumps when
attempting to compact due to too much soil moisture. ◾
