ASTM D7765-12

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Designation: D7765 − 12
Standard Practice for
Use of Foundry Sand in Structural Fill and Embankments
This standard is issued under the fixed designation D7765; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 This practice covers methods to use foundry sand as
C837 Test Method for Methylene Blue Index of Clay
embankment and structural fill.
D653 Terminology Relating to Soil, Rock, and Contained
1.2 It includes recommended construction (Section 5), com-
Fluids
pactioncontrol(Section6),andfreeze-thawdurability(Section
D698 Test Methods for Laboratory Compaction Character-
7) practices.
istics of Soil Using Standard Effort (12 400 ft-lbf/ft (600
kN-m/m ))
1.3 The engineer should be aware that foundry sand is a
by-product of metal casting industries. Various state, county, D1556 Test Method for Density and Unit Weight of Soil in
Place by Sand-Cone Method
and local environmental laws and regulations may apply if
foundry sand is used as an alternative embankment or fill D1557 Test Methods for Laboratory Compaction Character-
istics of Soil Using Modified Effort (56,000 ft-lbf/ft
material. It is advised that foundry sand users contact state,
county, and local environmental regulators to determine what (2,700 kN-m/m ))
D1883 Test Method for CBR (California Bearing Ratio) of
requirements or limitations may exist.
Laboratory-Compacted Soils
1.4 This standard applies to both green foundry sand and
D2216 Test Methods for Laboratory Determination of Water
chemically bonded foundry sand.
(Moisture) Content of Soil and Rock by Mass
1.5 The values stated in SI units are to be regarded as D2974 Test Methods for Moisture,Ash, and Organic Matter
standard. No other units of measurement are included in this
of Peat and Other Organic Soils
standard. D4327 Test Method for Anions in Water by Suppressed Ion
Chromatography
1.6 This standard does not purport to address all of the
D5080 Test Method for Rapid Determination of Percent
safety concerns, if any, associated with its use. It is the
Compaction
responsibility of the user of this standard to establish appro-
D5918 Test Methods for Frost Heave and Thaw Weakening
priate safety and health practices and determine the applica-
Susceptibility of Soils
bility of regulatory limitations prior to use.
D6026 Practice for Using Significant Digits in Geotechnical
1.7 This guide offers an organized collection of information
Data
or a series of options and does not recommend a specific
D6938 Test Method for In-Place Density and Water Content
course of action. This document cannot replace education or
of Soil and Soil-Aggregate by Nuclear Methods (Shallow
experience and should be used in conjunction with professional
Depth)
judgment. Not all aspects of this guide may be applicable in all
G51 Test Method for Measuring pH of Soil for Use in
circumstances. This ASTM standard is not intended to repre-
Corrosion Testing
sent or replace the standard of care by which the adequacy of
G187 Test Method for Measurement of Soil Resistivity
a given professional service must be judged, nor should this
Using the Two-Electrode Soil Box Method
document be applied without consideration of a project’s many
unique aspects. The word “Standard” in the title of this
3. Terminology
document means only that the document has been approved
3.1 For definitions related to geotechnical properties, see
through the ASTM consensus process.
Terminology D653.
This practice is under the jurisdiction of ASTM Committee D18 on Soil and
Rock and is the direct responsibility of Subcommittee D18.14 on Geotechnics of For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Sustainable Construction. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved June 1, 2012. Published August 2012. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
D7765-12. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7765 − 12
3.2 Definitions of Terms Specific to This Standard: 5.1.4 Foundrysandmaterialshouldbespreadintolooselifts
3.2.1 active clay content, n—the clay fraction that still can of approximately 20 cm thickness. The engineer may consider
thicker lift dimensions if it can be satisfactorily demonstrated
be hydrated.
with a test section that adequate compaction can be achieved
3.2.2 binders, n—additives used to hold the sand in the
over the full depth of the thicker lift.
required shape during the casting process. Binders may be
5.1.5 If necessary for proper compaction, water should be
inorganic, such as bentonite clay and sodium silicate, or
added to the foundry sand by the use of water distribution tank
organic such as phenolic-urethanes and epoxy-resins.
trucks. The water and foundry sand should be mixed using a
3.2.3 chemically bonded sand, n—foundry sand that con-
rototilling mixer or other approved method. At the time of
tains non-bentonite binders.
compaction, the foundry sand should have a moisture content
3.2.4 foundry sand, n—a narrowly graded fine sand with that will result in an after compaction dry density that complies
subangular to rounded grains that is a by-product of the steel
with the requirements of the project specifications. The dry
and aluminum casting industry. density is a function of the clay content.
5.1.6 The first pass in the compaction process should be
3.2.5 green foundry sand, n—a mixture of foundry sand,
accomplished by the method known as tracking. This involves
bentonite and seacoal. Most of foundry sand generated is green
the use of a bulldozer track to accomplish initial compaction.
foundry sand that contains bentonite clay and carbonaceous
The bulldozer is moved progressively across the foundry sand
additives, such as seacoal. Bentonite content of the green
until the entire area is tracked.
foundry sands is the key characteristics affecting their behav-
5.1.7 The foundry sand should subsequently be compacted
ior.
using pneumatic tired compaction equipment. Smooth steel
3.2.6 seacoal, n—a carbonaceous material added to foundry
drum and vibratory steel drum compactors are not as effective
sand to provide a reducing environment during casting and to
as pneumatic tired compactors for compacting foundry sand.
help ease the release of the cooled metal from the mold.
5.1.8 The foundry sand embankment should be compacted
as required by the specifying agency. The dry density is a
4. Significance and Use
function of the clay content. Foundry sand with no clay should
have a dry density equal to or greater than 1602 kg/m with an
4.1 Earthwork associated with highway construction pro-
vides an opportunity for high volume reuse of green foundry optimum water content of approximately 9 %. Increasing clay
content will increase dry density and optimum water content.
sands discarded by the foundry industry. This practice covers
methods and recommendations to use of foundry sand as 5.1.9 At the completion of each day’s work, the surface of
the foundry sand embankment should be sealed. This means
embankment and structural fill.
that it should be graded after compaction to the specification
4.2 This practice describes the unique construction consid-
requirement and rolled with a smooth steel roller so that rain
erations that may apply to foundry sands. The behavior may
will flow off the foundry sand instead of puddling.
vary due to specific composition of the material and local
5.1.10 The contractor should use water or other dust pallia-
conditions.
tives, if necessary, to control the generation of dust due to
4.3 The use of foundry sand in embankment and structural
drying of the foundry sand.
fill may be regulated by state and local codes. These codes
6. Compaction Control
should be consulted.
6.1 The use of foundry sand as structural fill and embank-
4.4 This practice is intended for use with green foundry
ment material can present compaction-related issues that may
sands where bentonite is used as the binder. It may not be
be different from those encountered with conventional sandy
applicable for chemically bonded foundry sands.
materials. Bentonite content of the green foundry sands is the
key characteristics affecting their constructability and perfor-
5. Construction Practices
mance behavior. The active clay content can be determined by
5.1 The following practices are recommended when con-
using methylene blue titration following Test Method C837.A
structing foundry sand embankment and structural fill.
description o
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