LWF is used in applications that a lightweight material is used to
reduce pressure on native soil for a variety of reasons.
In the SF Bay area, LWF is used as a replacement for the heavy Bay
Mud (LWF can be ½ the weight of Bay Area Mud), literally floating on
the surface of the mud and allowing structures to be safely built over
the top. It is also used in areas that need to relive pressure on river
bank, around buried pipes, and behind walls to reduce pressure as
well as to provide superior drainage.
There is more than one type of LWF. There are also combinations of
LWF and LW material that can be used for any particular application.
Caltrans has a very specific requirement for LWF, which includes a
very specific gradation and a strict maximum weight (generally 60 PCF
SSD), as well as a specific method of placing. The weights are
determined by samples taken at the plant pre job, and in the field
during their job. These samples are weighted, absorption is
determined, and the SSD weight is determined via a calculation. This
is the lightest material we manufacture, and is held to the Caltrans
However, there are other forms of LWF, from a 1.5” coarse aggregate
down to a 5/16” minus fill sand, not to mention Lightweight Gabions.
These can be used individually as well as in combination with each
other. They can be consolidated in place (Caltrans requirement) or
compacted, depending on the choice of the Soils Engineer. We will be
happy to assist you on any application.
|Light Weight Fill Projects
|Click below to view a
few LWF projects in