Page 19 - LWFC Catalog

2PM - Application of Lightweight Materials to the Support of Rail Systems Lightweight materials
2:50 PM have widespread use in the construction of lightweight embankments for roadway systems.
These materials are desirable due to their low mass, which reduces settlement, increases
bearing capacity, and improves slope stability. Unfortunately, a widespread application has
not been achieved for rail systems, even though lightweight materials offer the same benefits.
The relatively limited use of lightweight railway embankment is due, in part, to the additional
design, construction, and operational considerations and requirements specific to rail systems.
For example, the magnitude of dynamic rail deflection developed by a passing train atop
lightweight embankment is an important consideration for safe railway operations and long-
term track performance and maintenance. We will address this and other issues and show
examples of lightweight rail embankment performance for heavy, commuter, and light rail
systems worldwide.

2PM - Laboratory Tests for Characterizing EPS Geofoam EPS Geofoam have been tested
2:50 PM following different standards for compression, bending, tensile, shear, oedometer and direct
shear. Comparisons of results for two theoretical densisties, 20 and 40 kg/m3, are presented,
so the behaviour of the material according to this characterstic is understood. In addition, for
compression, flexion and tensile stress, results of EPS manufactured in Spain and Norway are also
studied.

4PM - Development of Permeability Testing for Permeable Low-Density Cellular Concrete Initial
4:50 PM testing for the hydraulic conductivity of Permeable Low Density Cellular Concrete (PLDCC) was
conducted via ASTM D5084 – “Standard Test Methods for Measurement of Hydraulic Conduc-
tivity of Saturated Porous Materials Using a Flexible Wall Permeameter”. In addition to the D5084
Test, ASTM C1701 – “Standard Test Method for Infiltration Rate of in Place Pervious Concrete”
was used. While ASTM C1701 is a somewhat effective means of measuring the infiltration rate
of water into in place PLDCC, it does not effectively measure permeability of fully saturated
PLDCC. The D5084 Test was a logical
first choice for testing PLDCC due to
thewide use of the test in the industry
and the ability to easily hold a sam-
ple in the flexible wall permeameter.
D5084 is well suited for low permeability
soils such as clay. Due to the limitations
of the D5084 procedure as outlined in
the specification, this method proved
incapable of measuring higher perme-
abilities encountered in PLDCC and
yielded erroneous results. ASTM D2434 –
“Standard Test Method of Permeability
of Granular Soils (Constant Head)” was
selected as a potential alternative test
method to the D5084 test. The D2434
test is more applicable to high perm-
ability materials such as compacted
sands and gravels. Although the D2434
method is better suited to the typical
ranges of permeability PLDCC, test-
ing this unique material presented ad-
ditional challenges. Modifications to
sample fabrication and preparation
for testing were necessary due to the
nature of PLDCC.

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