Standard Specification for

Fine Aggregate for Portland Cement Concrete

AASHTO Designation: M 6-03

1. SCOPE

1.1. This specification covers the quality and grading of fine aggregate for portland cement concrete used in pavements or bases, highway bridges, and incidental structures.

1.2. This specification is for use by a contractor, concrete supplier, or other purchaser as part of the purchase document describing the material to be furnished.

Note 1-This specification is regarded as adequate to ensure satisfactory materials for most concrete. It is recognized that, for certain work or in certain regions, it may be either more or less restrictive than needed. For example, where aesthetics are important, more restrictive limits may be considered regarding impurities that would stain the concrete surface. The specifier should ascertain that aggregates specified are or can be made available in the area of the work, with regard to grading, physical, or chemical properties, or combination thereof.

This specification is also for use in project specifications to define the quality of aggregate, the nominal maximum size of the aggregate, and other specific grading requirements. Those responsible for selecting the proportions for the concrete mixture shall have the responsibility of determining the proportions of fine and coarse aggregate and the addition of blending aggregate sizes if required or approved.

1.4. The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.5. The text of this standard references notes and footnotes that provide explanatory material. These notes (excluding those in tables and figures) shall not be considered as requirements of this standard.

REFERENCED DOCUMENTS

AASHTO Standards: M 80, Coarse Aggregate for Portland Cement Concrete M 92, Wire-Cloth Sieves for Testing Purposes T 2, Sampling of Aggregates T 11, Materials Finer than 75-pm (No. 200) Sieve in Mineral Aggregates by Washing T 21, Organic Impurities in Fine Aggregates for Concrete T 27, Sieve Analysis of Fine and Coarse Aggregates T 71, Effect of Organic Impurities in Fine Aggregate on Strength of Mortar T 103, Soundness of Aggregates by Freezing and Thawing

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W T 104, Soundness of Aggregate by Use of Sodium Sulfate or Magnesium Sulfate W T 112, Clay Lumps and Friable Particles in Aggregate

T 11 3, Lightweight Pieces in Aggregate T 16 1, Resistance of Concrete to Rapid Freezing and Thawing

ORDERING INFORMATION

The purchaser shall include the following ini'ormation in the purchase order or contract when applicable:

Reference to this specification, M 6, and year of issue;

Whether the deleterious substances limits for Class A or Class B apply, and limits on other deleterious substances (Section 7.1 and Note 4);

If the sulfate soundness requirement is waived (Section 8.5);

In the case of the sulfate soundness test (Section 8. l), which salt is to be used; if none is stated, either sodium sulfate or magnesium sulfate may be used;

If the supplementary requirement for reactive aggregates applies (Section Sl); and

Any exceptions or additions to this specification.

GENERAL REQUIREMENTS

Fine aggregate shall consist of natural sand or manufactured sand or combinations thereof, having hard, strong, durable particles.

Fine aggregate from different sources of supply shall not be mixed or stored in the same pile.

5. GRADING

5.1. Fine aggregate, when tested by means of laboratory sieves, shall conform to the requirements of Table I , except as provided in Sections 5.2 and 5.3:

Table I--Grading Requirements Mass,

Sieve Percent Passing 9.5 mm (ii8 in .) 100 4.75 mm (No. 4 ) 95 to 100 2.36 mm (No. 8) 80 to 100 1.18mm (No. 16) 50 to 85 600 pm (No. 30) 25 to 60 300 pm (No. 50) 10 to30 150 pm (No. 100) 2 to 10

TS-I c M 6-2 AASHTO

The minimum percent shown above for material passing the 300-pm (No. 50) and 150-pm (No. 100) sieves may be reduced to 5 and 0, respectively, if the aggregate is to be used in air- entrained concrete containing more than 237 kilograms of cement per cubic meter (400 lblyd3) or in non-air-entrained concrete containing more than 297 kilograms of cement per cubic meter (500 1blyd3) or if an approved mineral admixture is used to supply the deficiency in percent passing these sieves. Air-entrained concrete is here considered to be concrete containing air- entraining cement or an air-entraining agent and having an air content equal to or greater than 3.5 percent.

The fine aggregate shall have not more than 45 percent passing any sieve and retained on the next consecutive sieve of those shown in Section 5.1, and its fineness modulus shall be not less than 2.3 nor more than 3.1.

Fine aggregate failing to meet the sieve analysis and fineness modulus requirements of Sections 5.1, 5.2, or 5.3, may be accepted provided that concrete made with similar fine aggregate from the same source has an acceptable performance record in similar concrete construction; or, in the absence of a demonstrable service record, provided that it is demonstrated that concrete of the class specified, made with the fine aggregate under consideration, will have relevant properties at least equal to those of concrete made with the same ingredients with the exception that a reference fine aggregate be used which is selected from a source having an acceptable performance record in similar concrete construction.

Note 2-Fine aggregate that conforms to the grading requirements of a specification, prepared by another organization such as a state transportation agency, which is in general use in the area, should be considered as having a satisfactory service record with regard to those concrete properties affected by grading.

Note 3-Relevant properties are those properties of the concrete, which are important to the particular application being considered. STP 1 6 9 ~ ' provides a discussion of important concrete properties.

UNIFORMITY OF GRADING

6.1. For continuing shipments of fine aggregate from a given source, the fineness modulus shall not vary more than 0.20 from the base fineness modulus. The base fineness modulus shall be that value that is typical of the source. If necessary, the base fineness modulus may be changed when approved by the purchaser.

Note &The base fineness modulus should be determined from previous tests, or if no previous tests exist, from the average of the fineness modulus values for the first 10 samples (or all preceding samples if less than 10) on the order. The proportioning of a concrete mixture may be dependent on the base fineness modulus of the fine aggregate to be used. Therefore, when it appears that the base fineness modulus is considerably different from the value used in selecting proportions for the concrete mixture, a suitable adjustment in the mixture may be necessary.

7. DELETERIOUS SUBSTANCES

7.1. The amount of deleterious substances shall not exceed the following limits: (See Table 2.)

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Table 2-Deleterious Substances Limits Class A, Class B,

Max Mass, Max Mass, percent percent

Clay lumps and friable particles 3.0 3.0 Coal and lignite 0.25 I .O Material finer than 75-pm (No. 200) sieve:

a. In concrete subject to surface abrasion not more than

b. All other classes of concrete, not more than

Other deleterious substances (such as shale, alkali, mica, coated grains, and soft and flaky particles) Note 5 Note 5

Note 5-The purchaser or specifier, due to knowledge of the requirements of the work and the constituents of locally available aggregate, should insert appropriate requirements when needed.

Organic Impurities:

Fine aggregate shall be free of injurious amounts of organic impurities. Except as herein provided, aggregates subjected to the test for organic impurities and producing a color darker than the standard shall be rejected.

7.2.2. A fine aggregate failing in the test may be used, provided that the discoloration is due principally to the presence of small quantities of coal, lignite, or similar discrete particles.

7.2.3. A fine aggregate failing in the test may be used, provided that, when tested for the effect of organic impurities on strength of mortar, the relative strength at seven days calculated in accordance with T 71 is not less than 95 percent.

8. SOUNDNESS

8.1. Except as provided in Sections 8.2 through 8.5, fine aggregate subjected to five cycles of the soundness test shall have a weighted average loss not greater than 10 percent when sodium sulfate is used or 15 percent when magnesium sulfate is used.

8.2. Fine aggregate failing to meet the requirements of Section 8.1 may be accepted, provided that concrete of comparable properties, made from similar aggregate from the same source, has given satisfactory service when exposed to weathering similar to that to be encountered.

Fine aggregate not having a demonstrable service record and failing to meet the requirements of Section 8.1 may be accepted, provided it gives satisfactory results in concrete subjected to freezing and thawing tests. (See T 16 1 .)

Fine aggregate failing to meet the requirements given in Section 8.1 may, at the option of the purchaser or specifier, be subjected to an alternate freezing and thawing test of unconfined aggregate and may be accepted provided it gives satisfactory results.

Note 6-The purchaser or specifier should determine the details of the evaluation and criteria for determining satisfactory performance in Sections 8.2, 8.3, and 8.4.

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8.5. The requirements for soundness given in Section 8.1 may be waived in the case of aggregate for use in structures or portions of structures not exposed to weathering.

9. METHODS OF SAMPLING AND TESTING

9.1. Sampling and testing of fine aggregate shall be in accordance with the following methods of the American Association of State Highway and Transportation Officials:

9.1.2. Sieve Analysis and Fineness Modulus-T 27;

9.1.3. Clay Lumps and Friable Particles-T 1 12;

9.1.4. Coal andLignite-T 113, using a liquid of 2.0 specific gravity to remove the particles of coal and lignite; only material that is brownish-black, or black, shall be considered coal or lignite; coke shall not be classed as coal or lignite.

9.1.5. Material Finer than 75 pm (No. 2OOj-T 1 1 ;

9.1.6. Organic Impurities-T 2 1 ;

9.1.7. Effect o f Organic Impurities on Strength-T 7 1 ;

9.1.8. Sulfate Sotmdness-T 104;

9.1.9. Soundness (Unconfined Freezing and Thawing)-T 103; and

9.1 . lo . Freezing and Thawing of Concrete-T 16 1.

SUPPLEMENTARY REQUIREMENT The following supplementary requirement applies only when specifically stated in the order or contract.

S1. REACTIVE AGGREGATE

S1 . I . Fine aggregate used in concrete that will be subject to wetting, extended exposure to humid atmosphere, or contact with moist ground shall not contain any components that are known to be reactive with soluble alkalies from the concrete paste in an amount sufficient to cause deleterious expansion of mortar or concrete, without the accompanying use of some form of remediation in the concrete which is known to prevent deleterious expansion due to alkali-silica reactivity. The methods available to prevent deleterious expansion due to alkali-silica reactivity are outlined in AASHTO's Guide Specificationsfor Highway Construction. The method chosen for prevention of ASR in any one situation will depend on the materials available for remediation, the relative effectiveness of the available materials in preventing excessive expansion due to alkali-silica reactivity, and the reactivity of the aggregate intended for use in the concrete.

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Note 7-The benefits accrued by performing a minimal amount of testing to define the reactivity of the aggregate, and the most effective option for remediating the ASR potential of the aggregate, outweigh any minor delays resulting from the testing. Aggregate producers should be able to provide potential users test results demonstrating the reactivity level of their product on demand, which will speed the process of selecting a remediation option to prevent ASR.

I Signijcance of Tests and Properties of Concrete and Concrete Making Materials, STP 169B. ASTM, 1978.

TS-I c M 6-6 AASHTO