UNITED STATES DEPARTMENT OF AGRICULTURE

NATURAL RESOURCES CONSERVATION SERVICE

OREGON

# MATERIAL SPECIFICATION

[MS-203 CONCRETE]{.underline}

1\. [SCOPE]{.underline}

> This specification governs the quality of concrete mixes.

2\. [QUALITY]{.underline}

> Concrete mixes shall be composed of Portland cement, fine and coarse
> aggregate and water. An air-entraining admixture may be used.
>
> a\. Portland cement shall conform to the requirements of Material
> Specification MS-202.

b\. Fine and coarse aggregates shall conform to the requirements of
Material Specification MS-201. The aggregates shall be handled in a
manner to prevent contamination and segregation.

> c\. Water shall be clean and free from harmful chemicals (suitable for
> drinking).

d\. Air-entraining admixtures shall conform to the requirements of ASTM
C-260, Air Entraining Admixtures for Concrete.

e\. Class F fly ash meeting ASTM C-618 may be used in the concrete mix
to replace not more than 15% of the cement by weight. An independent
testing laboratory shall test pozzolanic materials with test results
included with the submittal of design mix.

f\. Water-reducing and set-retarding admixtures may be used upon
satisfactory submission of test results using a trial mix design and
manufacturer's certification of the admixture. The admixtures shall
conform to ASTM C-494.

g\. The concrete mix shall indicate evidence of meeting or exceeding the
following criteria unless otherwise shown on the drawings.

> \(1\) Minimum strength: 3000 lb.

\(2\) Slump: ASTM C-143, 3-5 inches.

\(3\) Cement: ASTM C-150, Type I, IA, II, IIA, V or VA.\
Minimum content: 6 sacks per CY concrete (94 lb. sacks).

\(4\) Water: Clean potable and free of foreign matter.\
Maximum water-cement ratio; 0.45 - 0.55 (6 gallons per sack of
concrete).

\(5\) Aggregates: Clean durable and within the grading limits of ASTM
C-33.

> Coarse Aggregates; maximum size shall be 3/4 inch unless otherwise
> stated on the drawing.
>
> Fine Aggregates; fineness module shall be greater than 2.3 but less
> than 3.1.
>
> Fine to Total Aggregate Ratio; greater than 0.35 but less than 0.45.

\(6\) If Air Entrained, concrete mixes shall have 5-8% volume of air
using an air entraining admixture.

3\. [INSPECTION AND TESTING]{.underline}

> The following is a partial listing of the common American Society for
> Testing and Materials, ASTM, test requirements for concrete that may
> be used to verify concrete quality:
>
> a\. ASTM C-31, "Making and Curing Concrete Compressive and Flexure
> Strength Test Specimens in the Field."
>
> b\. ASTM C-33, "Concrete Aggregates."
>
> c\. ASTM C-39, "Compressive Strength of Cylindrical Concrete
> Specimens."
>
> d\. ASTM C-94, "Ready-Mix Concrete."
>
> e\. ASTM C-143, "Slump of Portland Cement Concrete."
>
> f\. ASTM C-150, "Portland Cement."
>
> g\. ASTM C-172, "Sampling Freshly Mixed Concrete."
>
> h\. ASTM C-23l, "Air Content of Freshly Mixed Concrete by the Pressure
> Method."
>
> i\. ASTM C-260, "Air Entraining Admixtures for Concrete."
>
> j\. ASTM C-494, "Chemical Admixtures for Concrete."
>
> The NRCS shall have free entry to the plant to review the equipment
> used for mixing, dispersing, weighing, agitating and delivering
> concrete. Proper facilities shall be provided for inspecting
> materials, equipment and processes and to obtain samples of the
> ingredients and concrete. All tests and inspections will be conducted
> so as not to unnecessarily interfere with the manufacture and delivery
> of the concrete.

4\. [HANDLING AND MEASURING MATERIALS]{.underline}

> Materials shall be stored and handled in a manner that will prevent
> degradation, segregation, contamination or intermixing of materials
> before measurement.
>
> Scales for weighing aggregates and cement shall be beam or springless
> dial type, clean and operating within 1 percent accuracy for cement
> and 2 percent accuracy for aggregates.
>
> All materials entering into the concrete shall be mechanically
> measured by weight except the air entraining admixture and water,
> which may be measured by volume.

5\. [MIXERS AND MIXING]{.underline}

> Concrete may be furnished by batch mixing at the work site or by
> ready-mix methods.