Portland Cement
Blended Cement
Masonry Cement
Pozzolan
Concrete
Masonry Mortar
Concrete Masonry Units
Steel Reinforcing Bar
CCRL Proficiency Sample Programs also support accreditation
programs conducted by others. Participation in proficiency sample programs also
permits laboratories to check consistency of their testing. Results from such programs
can be used to evaluate quality of testing between laboratories, and to help
identify problems with equipment or procedures. Laboratories are required by
ASTM C1222 and C1077 to participate in a proficiency sample program.
The Proficiency Sample Programs were developed as a means for a laboratory to
monitor the quality of its testing between CCRL on-site assessments. The programs
are overseen by ASTM Committees C-1 on Cement and C-9 on Concrete and Concrete
Aggregates. Responsibility for the assignment of fees is assumed by the
committees, and their payment is made to ASTM.
The Proficiency Sample Programs are based on the two-sample system described in
papers by Youden [1], and by Crandall and Blaine [2] in the 1959 Proceedings of
the American Society for Testing and Materials.
All programs are conducted in a similar manner. At intervals of either 6 or 12
months, quantities of two slightly different lots of a material (cements, pozzolans,
concrete aggregates, masonry sand, and masonry units) are procured from commercial sources.
This material is then homogenized using well defined procedures and divided into individual
test samples at the National Institute of Standards and Technology (NIST).
Special instructions, and all necessary reporting forms, are furnished with each set of
samples. The test procedures to be performed are taken from current ASTM
specifications. The specified tests are performed and the results reported to
the CCRL for review and evaluation. Test results reported by an individual
laboratory are treated confidentially as to source.
Approximately six weeks after the samples are distributed, all participants receive
a preliminary report which shows tentative average values and standard deviations
for each determination, based on a limited number of returned results.
Within two months, a detailed final report is distributed. This report contains
average values, standard deviations based on all applicable data, and scatter
diagrams. In addition, precision values and other statistical information are
produced for use by ASTM committees and other interested organizations.
Scatter diagrams are prepared for each test performed by the laboratories. For each
pair of samples, the test results of the odd-numbered sample are plotted on the
X (horizontal) axis, and the results of the even-numbered sample are plotted on
the Y (vertical) axis. A substantial variation of its test values from the
center of the diagram is generally of concern to a laboratory. A continuing
trend of large variations indicates a need for some corrective action, either
in apparatus or technique.
To focus attention on significant deviations from the average, each laboratory is
given a rating on each determination using a rating scale based on the standard
deviation. The ratings have no significance beyond indicating the difference
between the individual laboratory result and the average for a particular test.
To help give meaning to the ratings obtained by an individual laboratory over a
given period of time, performance charts were developed. These charts, which
are distributed annually to laboratories, visually show a participant's
deviation from the average value on the ten most recent sample pairs, thereby
providing a means of monitoring the general tendencies and bias of a
laboratory's test results. This information gives some indication of a
laboratory's overall proficiency for given tests.
References
1. Youden, W. J., "Statistical Aspects of the Cement Testing Program", Proceedings, American Society
for Testing and Materials, Vol. 59, 1959, p. 1120.
2. Crandall, J. R. and Blaine, R. L., "Statistical Evaluation of Interlaboratory Cement Tests",
Proceedings, American Society for Testing and Materials, Vol. 59, 1959, p. 1129.
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The Portland Cement Proficiency Sample Program provides for the distribution of
a pair of chemical and physical test samples of portland cement twice a year.
Samples for the physical tests weigh approximately 7 kg each, and are packaged
in plastic bags. Samples for the chemical analyses weigh approximately 20 grams
each, and are packed in glass vials. Test samples are shipped to participants
in July and January.
The physical determinations to be made on each sample cover the tests for
portland cement to which reference is made in the current edition of ASTM Standard
Specification for Portland Cement (C150), and include the following:
1. Normal Consistency, C187
2. Time of Setting byVicat Needle, C191
3. Time of Setting by Gillmore Needles, C266
4. Autoclave Expansion, C151
5. Air Content of Mortar, C185
6. Compressive Strength of Mortar (3, 7, and 28 days), C109
7. Fineness by Air Permeability Apparatus, C204
8. Fineness by the Turbidimeter, C115
9. Fineness by the 45µ (No. 325) Sieve, C430
10. Early Stiffening (Paste Method), C451
11. Heat of Hydration (7 and 28 days), C186
12. Expansion of Hydraulic Cement Mortar Bars Stored in Water, C1038
The same cement is used for both chemical and physical tests. Normally, one vial is
furnished with each chemical sample. Additional vials for use in instrumental
determinations may be obtained, if requested in advance of the indicated
distribution dates.
The chemical tests to be performed include the following:
1. Silicon Dioxide (SiO2)
2. Aluminum Oxide (A12O3)
3. Ferric Oxide (Fe2O3)
4. Calcium Oxide (CaO)
5. Free Lime
6. Magnesium Oxide (MgO)
7. Sulfur Trioxide (SO3)
8. Loss on Ignition
9. Insoluble Residue
10. Sodium Oxide (Na2O)
11. Potassium Oxide (K2O)
12. Titanium Dioxide (TiO2)
13. Phosphorus Pentoxide (P2O5)
14. Zinc Oxide (ZnO)
15. Chloride (Cl)
16. Manganic Oxide (Mn2O3)
17. Carbon Dioxide (CO2)
18. Limestone Content
19. Chromium Oxide (Cr2O3)
Unless otherwise specified, the procedure to be used in making these tests is the one
customarily followed by the laboratory.
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The Blended Cement Proficiency Sample Program provides for the distribution of
one pair of chemical and physical test samples per year. Samples for the
physical tests weigh approximately 6 kilograms each, and are packaged in plastic
bags. Samples for the chemical analyses weigh approximately 20 grams each, and
are packed in glass vials. Samples are shipped to participants in February.
Physical and chemical determinations on each sample are to be made in
accordance with the current edition of the ASTM Specification for Blended
Hydraulic Cements (C595) and the various standards and specifications to which it refers.
The physical tests to be performed include the following:
1. Normal Consistency, C187-C595
2. Time of Setting by Vicat Needle, C191
3. Autoclave Expansion, C151-C595
4. Air Content of Mortar, C185-C595
5. Density, C188
6. Compressive Strength of Mortar (3 and 7 day), C109
7. Fineness by Air Permeability Apparatus, C204
8. Fineness by the 45 µm (No. 325) Sieve, C430
9. Heat of Hydration (7 and 28 day), C186
The cement used for the chemical tests is the
same as that used for the physical tests.
The chemical tests to be performed are as follows:
1. Silicon Dioxide (SiO2
2. Aluminum Oxide (A12O3)
3. Ferric Oxide (Al2O3
4. Calcium Oxide (CaO)
5. Magnesium Oxide (MgO)
6. Sulfur Trioxide (SO3)
7. Sulfide Sulfur (S)
8. Insoluble Residue
9. Loss on Ignition
10. Sodium Oxide (Na2O)
11. Sulfide Sulfur (S)
12. Potassium Oxide (K2O)
13. Phosphorus Pentoxide (P2O5)
14. Zinc Oxide (ZnO)
15. Manganic Oxide (Mn2O3)
16. Chloride (Cl)
17. Chromium Oxide (Cr2O3)
Unless otherwise specified, the procedure to be used in making these tests is the one customarily followed by the laboratory.
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The Masonry Cement Proficiency Sample Program provides for the distribution of
one pair of test samples per year. Each sample weighs approximately 6.5
kilograms and is packaged in a plastic bag. Samples are shipped to participants
in August.
The physical determinations on each sample are to be made in accordance with the
current edition of the ASTM Standard Specification for Masonry Cement (C91) and
the various methods and specifications to which it refers.
The tests to be performed include the following:
1. Normal Consistency, C187
2. Time of Setting by Gillmore Needles, C266
3. Autoclave Expansion, C151
4. Air Content of Mortar, C185
5. Compressive Strength of Mortar (7 and 28 days), C109
6. Fineness by the 45 µm (No. 325) Sieve, C430
7. Water Retention, C91
8. Density, C188
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The Pozzolan Proficiency Sample Program provides for the distribution of a pair
of chemical and physical test samples. Both pozzolans used for the chemical sample
pair are either ASTM Class C or Class F fly ashes. Samples for the chemical analysis weigh
approximately 30 grams each, and are packaged in glass vials. Samples for
physical testing include approximately 2.3 kg each of pozzolan,and approximately
18 kg of a companion portland cement. Samples are shipped to participants in July.
Physical and chemical determinations on each sample are to be made in
accordance with the current edition of the ASTM Standard Test Method for
Sampling and Testing Fly Ash or Natural Pozzolans for Use as a Mineral Admixture
in Portland-Cement Concrete (C311) and the various methods to which it refers.
The physical tests to be performed include the following:
1. Density
2. Fineness by No. 325 Sieve
3. Increase of Drying Shrinkage of Mortar Bars
4. Soundness by Autoclave Soundness
5. Air-Entrainment of Mortar
6. Strength Activity Index with Portland Cement
7. Effectiveness of Mineral Admixtures in Controlling Alkali Silica-Reactions
The chemical tests to be performed include thefollowing:
1. Moisture Content
2. Silicon Dioxide (SiO2
3. Aluminum Oxide (A12O3)
4. Ferric Oxide (Al2O3
5. Calcium Oxide (CaO)
6. Magnesium Oxide (MgO)
7. Sulfur Trioxide (SO3)
8. Loss on Ignition
9. Available Alkalies
Unless otherwise specified, the procedure to be
used in making these tests is the one customarily
followed by the laboratory.
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The Concrete Proficiency Sample Program provides for the distribution of a pair
of samples twice a year. For each individual sample portland cement, coarse aggregate,
and fine aggregate are packaged separately. The quantity of material needed for this sample makes
it necessary to send the sample pair in four cartons, each weighing
approximately 30 kilograms. The material furnished in each sample is sufficient
to perform tests for slump, air content, unit weight, and to make two 6 by 12
inch (150 by 300 mm), or three 4 by 8 inch (100 by 200 mm) test cylinders.
Samples are shipped to participants in April and November.
The ASTM standards on which prescribed tests are based are as follows:
1. Compressive Strength of Cylindrical Concrete Specimens, C39
2. Unit Weight of Concrete, C138
3. Slump of Portland Cement Concrete, C143
4. Air Content of Freshly Mixed Concrete by the Volumetric Method, C173
5. Making and Curing Concrete Test Specimens in the Laboratory, C192
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The masonry mortar program provides for the distribution of one pair of test
samples per year. The cement portion of each sample weighs approximately 6.500
kg,and is packaged in plastic bags. The masonry sand portion, used for both
samples, is packaged in one container of 15kg. The materials for the sample
are purchased from commercial sources, blended and packaged at the National
Institute of Standards and Technology, and shipped to the participants.
The tests to be performed are taken from current ASTM Specification C270
and included the following test methods as modifed by C270:
1. Air Content, C91/C185
2. Compressive Strength, C109
3. Water Retention, C91
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The concrete masonry unit program provides for the distribution of one pair of
test samples per year. Each sample consists of six 4x8x8 inch units for a total
of twelve units. The units are procured with the help of the National Concrete
Masonry Association (NCMA) and are randomized and packaged at the National
Institute of Standards and Technology. The units are packaged in specially
designed corrugated boxes to prevent damage, and mailed to participants.
The tests to be performed are taken from current ASTM Specification C140 and
include the following:
1. Measurement of dimensions
1.1 Face shell thickness
1.2 Web thickness
2. Compressive Strength
3. Absorption
4. Density
The steel reinforcing bar program provide for the distribution of one pair of test
samples per year. Each sample consists of three bars approximately 30 inches in length
usually conforming to A615 orA706. This material is procured with thehelp of
ASTM Subcommittee A01.05 on steel reinforcement. The specimens are cut, randomize, and
packaged by CCRL. Samples are distributed in July.
Tests to be performed the following:
1. Weight per Unit Length
2. Measurementof Deformations
3. Average Height
4. Gap
5. Tensile Strength
6. Yield Strength
7. Elongation
A laboratory wishing to join any of the programs may do so by sending a
request form along with a check made out to ASTM for the full amount of
the plus shipping charges. The appropriate
request form
with program fee and shipping charge can be obtained by contacting CCRL.
On receipt of the request and payment, the laboratory is added to the
list of participants, sent a letter of confirmation and an invoice marked
"paid", and given an individualized laboratory identification number.
Requests received less than 60 days prior to the sample distribution
cannot be ensured enrollment in the current sample.
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