ASTM D7765-18a

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Designation: D7765 − 18 D7765 − 18a
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 Scope*
1.1 This practice covers methods to use foundry sand as embankment and structural fill.
1.2 This practice includes recommended construction (Section 5), compaction control (Section 6), and freeze-thaw durability
(Section 7) practices.
1.3 The engineer should be aware that foundry sand is a by-product of metal casting industries. Various local, state/provincial/
regional, or national/federal environmental laws and regulations may apply if foundry sand is used as an alternative embankment
or fill material. It is advised that foundry sand users contact appropriate environmental regulators to determine what requirements
or limitations may exist.
1.4 This standard primarily applies to both green foundry sand and also generally to chemically bonded foundry sand.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.7 This practice offers a set of instructions for performing one or more specific operations. This document cannot replace
education or experience and should be used in conjunction with professional judgment. Not all aspects of this guide may be
applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the
adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project’s
many unique aspects. The word “Standard” in the title of this document means only that the document has been approved through
the ASTM consensus process.
1.8 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
C837 Test Method for Methylene Blue Index of Clay
D653 Terminology Relating to Soil, Rock, and Contained Fluids
3 3
D698 Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort (12,400 ft-lbf/ft (600 kN-m/m ))
D1556 Test Method for Density and Unit Weight of Soil in Place by Sand-Cone Method
D1557 Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort (56,000 ft-lbf/ft (2,700
kN-m/m ))
D1883 Test Method for California Bearing Ratio (CBR) of Laboratory-Compacted Soils
D2216 Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass
D2974 Test Methods for Moisture, Ash, and Organic Matter of Peat and Other Organic Soils
D4327 Test Method for Anions in Water by Suppressed Ion Chromatography
D5080 Test Method for Rapid Determination of Percent Compaction
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 Sustainable
Construction.
Current edition approved Jan. 1, 2018May 1, 2018. Published February 2018May 2018. Originally approved in 2018. Last previous edition approved in 20122018 as
D7765–12.–18. DOI: 10.1520/D7765-18.10.1520/D7765-18A.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7765 − 18a
D5918 Test Methods for Frost Heave and Thaw Weakening Susceptibility of Soils
D6026 Practice for Using Significant Digits in Geotechnical Data
D6938 Test Methods for In-Place Density and Water Content of Soil and Soil-Aggregate by Nuclear Methods (Shallow Depth)
G51 Test Method for Measuring pH of Soil for Use in Corrosion Testing
G187 Test Method for Measurement of Soil Resistivity Using the Two-Electrode Soil Box Method
3. Terminology
3.1 Definitions:
3.1.1 For definitions of common technical terms in this standard, refer to Terminology D653.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 active clay content, n—the clay fraction that still can be hydrated.
3.2.2 binders, n—additives used to hold the sand in the required shape during the casting process. Binders may be inorganic,
such as bentonite clay and sodium silicate, or organic such as phenolic-urethanes and epoxy-resins.
3.2.3 chemically bonded sand, n—foundry sand that contains non-bentonite binders.
3.2.4 foundry sand, n—a narrowly graded fine sand with subangular to rounded grains that is a by-product of the steel iron, steel,
and aluminum casting industry.
3.2.5 green foundry sand, n—a mixture of foundry sand, bentonite and seacoal. Most of foundry sand generated is green foundry
sand that contains bentonite clay and carbonaceous additives, such as seacoal. Bentonite content of the green foundry sands is the
key characteristic that affects their behavior.
3.2.6 seacoal, n—a carbonaceous material added to foundry sand to provide a reducing environment during casting and to help
ease the release of the cooled metal from the mold.
4. Significance and Use
4.1 Earthwork associated with highway construction provides an opportunity for high volume reuse of green foundry sands
discarded by the foundry industry. This practice covers methods and recommendations to use of foundry sand as embankment and
structural fill.
4.2 This practice describes the unique construction considerations that may apply to foundry sands. The behavior may vary due
to specific composition of the material and local conditions.
4.3 The use of foundry sand in embankment and structural fill may be regulated by local, state/provincial/regional, or
national/federal regulations. These regulations should be consulted.
4.4 This practice is intended for use with green foundry sands where bentonite is used as the binder. It may not be applicable
for chemically bonded foundry sands.
5. Construction Practices
5.1 The following practices are recommended when constructing foundry sand embankment and structural fill.
5.1.1 Foundry sand should be conditioned for dust control and to prevent erosion by the addition of between 10 and 15 percent
water by mass at the source site prior to delivery. This conditioning may include subsequent storage (stockpiling) of the foundry
sand for a period of 24 h or more, after the addition of water, until the water is evenly dispersed. If the supplier can demonstrate
that water is evenly distributed throughout the foundry sand, then stockpiling may not be required.
5.1.2 Delivery of foundry sand should be in closed or covered trucks.
5.1.3 Large-scale storage (stockpiling) of foundry sand at the site is permissible provided that the water content is maintained
at 10 to 15 percent by mass for dust control.
5.1.4 Foundry sand material should be spread into loose lifts of approximately 200 mm thickness. The engineer may consider
thicker lift dimensions if it can be satisfactorily demonstrated with a test section that adequate compaction can be achieved over
the full depth of the thicker lift.
5.1.5 If necessary for proper compaction, water should be added to the foundry sand by the use of water distribution tank trucks.
The water and foundry sand should be mixed using a rototilling mixer or other approved method. At the time of compaction, the
foundry sand should have a moisture content that will result in an after compaction dry density that complies with the requirements
of the project specifications. The dry density is a function of the clay content.
5.1.6 The first pass in the compaction process should be accomplished by the method known as tracking. This involves the use
of a bulldozer track to accomplish initial compaction. The bulldozer is moved progressively across the foundry sand until the entire
area is tracked.
5.1.7 The foundry sand should subsequently be compacted using pneumatic tired compaction equipment. Smooth steel drum
and vibratory steel drum compactors are not as effective as pneumatic tired compactors for compacting foundry sand.
D7765 − 18a
5.1.8 The foundry sand embankment should be compacted as required by the specifying agency. The dry density is a function
of the clay content. Foundry sand with no clay should have a dry density e
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