Expanded polystyrene (EPS)
Geofoam is a versatile and lightweight material designed to address specific
engineering and construction challenges where the combination of low weight and
high strength is advantageous. These characteristics made EPS geofoam an
excellent alternative to natural materials for the feasibility of many
construction projects that would otherwise destined, for time and
implementation costs, to be postponed or alienated. Specifically, this
technology has been successfully used in road infrastructure sector in the
construction of roads, bridge abutments, lightweight embankments and backfills,
above all for the rapid restoration of compromised roads following landslide or
calamitous events, representing an interesting and resilient solution in areas
exposed to seismic risk or persistent vibratory actions.
EPS
Geofoam application in road construction
EPS Geofoam is often used
for road highway construction and has been across the world since the 1970’s.
The use of a lightweight fill material like EPS geofoam blocks has enabled
roads to be built faster, lighter, and with greater stability than they would
have with other similar fill materials. Blocks are stacked up to a desired
elevation and then typically covered in a geomembrane before being topped with
asphalt or concrete. The use of geofoam road construction saves time, money,
and effectively allows contractors and architects in the field to adjust their
project as they see fit based on field conditions. It is a very forgiving and
easy to use material.
Road
construction over poor soils
In many cases new roads are
required to be constructed over soft or loose soils that are incapable of
supporting additional loads. EPS geofoam can be used to build roads on soft
soils or where sensitive existing utilities or wetlands are present. EPS
geofoam can be used to replace compressible soils or in place of heavy fill
materials to prevent unacceptable loading on underlying soils and adjacent
structures. The high compressive resistance of EPS geofoam makes it able to
adequately support traffic loadings. Construction of roads with EPS geofoam
also saves time and cost as it is easy to handle without the need for special
equipment.
Road
widening
Roadways often have to be
widened to reduce congestion. This situation results in additional fill being
required for the roadway to be widened. This can be an expensive and
time-consuming process if the soils adjacent to the existing roadway are not
adequate to support the traffic loads because the resulting settlement can
impact the existing roadway. In traditional construction, soil embankments are
built in thin lifts, each of which must be compacted before the next lift is
placed. Using EPS geofoam eliminates the need for compaction and fill testing,
reduces the construction time and minimizes impact to the existing roadway and
adjacent structures and/or buried utilities. The high compressive resistance of
EPS geofoam makes it able to withstand the induced traffic forces without
causing unacceptable loading of the underlying soils or adjacent fill. In
addition, it may be possible to build steeper slopes using EPS geofoam than
soil, which can reduce the amount of additional right-of-way that needs to be
acquired.
Road
embankments
Construction of roadway
embankments on soft foundation soil such as marine clay is always a major issue
due to poor load carrying capacity and excessive settlements. The two main
approaches for coping with the problem is to improve the engineering
properties, e.g., shear strength and compressibility, of the foundation soils
or reduce the weight of the embankment and thus the load applied to the
foundation soils. The first approach of improving the engineering properties of
foundation soil and its strengthening may be very difficult due to certain
reasons such as differing in soil strata or soil strata may not be known
accurately. However, the second approach have been increasingly employed using
the lightweight EPS geofoam to reduce the weight of the embankment. A
significant improvement is obtained in terms of load carrying capacity due to
provision of EPS geofoam embankment over clay bed. It is due to compressibility
of EPS geofoam material where initially load is carried by the blocks placed in
a layer and then slowly transferred to the soil beneath resulting into improved
load carrying capacity.
EPS geofoam block usage has
been increasing for a number of reasons including it exhibits the lowest
density/unit weight and thus the smallest impact on the soft foundation soils,
exhibits consistent material properties because it is manufactured, is easy and
fast to construct even in adverse weather conditions, results in decreased
maintenance costs as a result of less settlement from the low density of EPS
geofoam.
EPS
Geofoam application in bridge construction
One of the major
applications that EPS geofoam block material is used for is to support bridge
construction. EPS geofoam blocks have a high compressive resistance rate which
makes it perfect to support oncoming traffic and the repeated stress and
compression that takes place on structures like bridges.
EPS geofoam insulation
blocks can be layered and shaped to create bridge abutments and provides a
sturdy foundation that’s both cost-effective and more optimal than other
traditional fill materials such as soil, concrete and rocks.
EPS Geofoam can be used to
support bridges when designed to the proper specification. The material adds
little additional load to the underlying ground and therefore is a perfect
material for the construction of a bridge structure. The soil underneath these
bridge abutments is barely impacted because the lower weight of EPS geofoam
imposes the least amount of stress on it. As a result, the surrounding
environment becomes more sustainable and acts as a stronger, longer-lasting
foundation for a bridge.
In cases of a bridge being
rehabilitated because it is no longer structurally stable enough to hold the
loads of current traffic, EPS Geofoam infill can help support the span and
transfer the traffic load safely to the building foundation or underlying soil.
EPS geofoam is being used
more and more as the main material to build bridge abutments thanks to the
multiple benefits it brings versus concrete and other traditional filling
methods. For one, it is extremely cost-effective because of the flexibility it
offers. Labour costs and timelines for construction projects are cut down due
to the benefits of its lightweight and customizable features. EPS geofoam
construction blocks also minimizes maintenance because of the material has a
durable compression factor. Another positive of using EPS geofoam to form
bridge abutments is that it does not breakdown. This is particularly relevant
within the context of bridge construction because bridges are often placed in
environments that have natural elements surrounding them, and these external
factors like soil and moisture can work to impose wear and tear on supporting
structures that make up the bridge. EPS geofoam is resistant to potential
damaging factors.
