ATTACHMENT D.pdf

Designation: C109/C109M − 24

Standard Test Method for

Compressive Strength of Hydraulic Cement Mortars (Using 50 mm [2 in.] Cube Specimens)1

This standard is issued under the fixed designation C109/C109M; 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.

This standard has been approved for use by agencies of the U.S. Department of Defense.

1. Scope*

1.1 This test method covers determination of the compres-

sive strength of hydraulic cement mortars, using 50 mm [2 in.] cube specimens.

NOTE 1—Test Method C349 provides an alternative procedure for this determination (not to be used for acceptance tests).

1.2 This test method covers the application of the test using either SI or inch-pound units. The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text, the inch-pound units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.

1.3 Values in SI units shall be obtained by measurement in

SI units or by appropriate conversion, using the Rules for

Conversion and Rounding given in IEEE/ASTM SI-10, of measurements made in other units.

1.4 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 appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.

(Warning—Fresh hydraulic cementitious mixtures are caustic and may cause chemical burns to skin and tissue upon prolonged exposure.2)

1.5 This international standard was developed in accor-

dance with internationally recognized principles on standard-ization established in the Decision on Principles for the

Development of International Standards, Guides and Recom-mendations issued by the World Trade Organization Technical

Barriers to Trade (TBT) Committee.

2. Referenced Documents

2.1 ASTM Standards:3

C91/C91M Specification for Masonry Cement

C114 Test Methods for Chemical Analysis of Hydraulic

Cement

C150/C150M Specification for Portland Cement

C230/C230M Specification for Flow Table for Use in Tests of Hydraulic Cement

C305 Practice for Mechanical Mixing of Hydraulic Cement

Pastes and Mortars of Plastic Consistency

C349 Test Method for Compressive Strength of Hydraulic-

Cement Mortars (Using Portions of Prisms Broken in

Flexure)

C511 Specification for Mixing Rooms, Moist Cabinets, Moist Rooms, and Water Storage Tanks Used in the

Testing of Hydraulic Cements and Concretes

C595/C595M Specification for Blended Hydraulic Cements

C618 Specification for Coal Ash and Raw or Calcined

Natural Pozzolan for Use in Concrete

C670 Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials

C778 Specification for Standard Sand

C989/C989M Specification for Slag Cement for Use in

Concrete and Mortars

C1005 Specification for Reference Masses and Devices for

Determining Mass and Volume for Use in Physical Testing of Hydraulic Cements

C1157/C1157M Performance Specification for Hydraulic

Cement

C1328/C1328M Specification for Plastic (Stucco) Cement

C1329/C1329M Specification for Mortar Cement

C1437 Test Method for Flow of Hydraulic Cement Mortar

E4 Practices for Force Calibration and Verification of Test-ing Machines

2.2 IEEE/ASTM Standard:3

IEEE/ASTM SI-10 Standard for Use of the International

System of Units (SI): The Modern Metric System 1 This test method is under the jurisdiction of ASTM Committee C01 on Cement and is the direct responsibility of Subcommittee C01.27 on Strength.

Current edition approved Oct. 15, 2024. Published January 2025. Originally approved in 1934. Last previous edition approved in 2023 as C109/C109M – 23.

DOI: 10.1520/C0109_C0109M-24.

2 See the section on Safety, Manual of Cement Testing, Annual Book of ASTM

Standards, Vol 04.01.

3 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at www.astm.org/contact. 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

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.

Caleb Gunter (SOUTH CAROLINA STATE DEPT. OF TRANSPORTATION) pursuant to License Agreement. No further reproductions authorized.

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3. Summary of Test Method

3.1 The mortar used consists of 1 part cement and 2.75 parts

of sand proportioned by mass. Portland, air-entraining portland, portland-limestone, or air-entraining portland-limestone cements are mixed at a specified water content.

Water content for other cements is that sufficient to obtain a flow of 110 6 5 in 25 drops of the flow table. The 50 mm

[2 in.] test cubes are compacted by tamping in two layers. The cubes are cured one day in the molds and stripped and immersed in lime water until tested.

4. Significance and Use

4.1 This test method provides a means of determining the

compressive strength of hydraulic cement and other mortars and results may be used to determine compliance with speci-fications. Further, this test method is referenced by numerous other specifications and test methods. Caution must be exer-cised in using the results of this test method to predict the strength of concretes.

5. Apparatus

5.1 Weights and Weighing Devices, shall conform to the

requirements of Specification C1005. The weighing device shall be evaluated for precision and accuracy at a total load of

2000 g.

5.2 Glass Graduates, of suitable capacities (preferably large enough to measure the mixing water in a single operation) to deliver the indicated volume at 20 °C [68 ºF]. The permissible variation shall be 62 mL. These graduates shall be subdivided to at least 5 mL, except that the graduation lines may be omitted for the lowest 10 mL for a 250 mL graduate and for the lowest 25 mL of a 500 mL graduate. The main graduation lines shall be circles and shall be numbered. The least graduations shall extend at least one seventh of the way around, and intermediate graduations shall extend at least one fifth of the way around.

5.3 Specimen Molds, for the 50 mm [2 in.] cube specimens

shall be tight fitting. The molds shall have not more than three cube compartments. The mold sides shall be separable into not more than two parts. The parts of the molds when assembled shall be positively held together. The molds shall be made of hard metal not attacked by the cement mortar. For new molds the Rockwell hardness number of the metal shall be not less than 55 HRB. The sides of the molds shall be sufficiently rigid to prevent spreading or warping. The interior faces of the molds shall be plane surfaces and shall conform to the tolerances of Table 1.

5.3.1 Cube molds shall be checked for conformance to the

design and dimensional requirements of this test method at least every 2 1⁄2 years.

5.4 Mixer, Bowl, and Paddle, an electrically driven me-

chanical mixer of the type equipped with paddle and mixing bowl, as specified in Practice C305.

5.5 Flow Table and Flow Mold, conforming to the require-

ments of Specification C230/C230M.

5.6 Tamper, a nonabsorptive, nonabrasive, nonbrittle mate-

rial such as a rubber compound having a Shore A durometer hardness of 80 6 10 or seasoned oak wood rendered nonab-sorptive by immersion for 15 min in paraffin at approximately

200 °C [392 °F], shall have a cross section of 13.0 mm 6

1.6 mm by 25.0 mm 61.6 mm [0.50 in. 6 0.06 in. by 1.00 in.

6 0.06 in.] and a length of 120 mm to 150 mm [5 in. to 6 in.].

The tamping face shall be flat and at right angles to the length of the tamper.

5.6.1 Tampers shall be checked for conformance to the

design and dimensional requirements of this test method at least every six months.

NOTE 2—Each day that the tamper is used a visual inspection should confirm that the end is flat and at a right angle to the long axis of the tamper. Rounded or peeling tampers should not be allowed for use.

5.7 Trowel, having a steel blade 100 mm to 150 mm [4 in. to

6 in.] in length, with straight edges.

5.8 Moist Cabinet or Room, conforming to the require-

ments of Specification C511.

5.9 Testing Machine, either the hydraulic or the screw type, with sufficient opening between the upper bearing surface and the lower bearing surface of the machine to permit the use of verifying apparatus. The load applied to the test specimen shall be indicated with an accuracy of 61.0 %. If the load applied by the compression machine is registered on a dial, the dial shall be provided with a graduated scale that can be read to at least the nearest 0.1 % of the full scale load (Note 3). The dial shall be readable within 1 % of the indicated load at any given load level within the loading range. In no case shall the loading range of a dial be considered to include loads below the value that is 100 times the smallest change of load that can be read on the scale. The scale shall be provided with a graduation line equal to zero and so numbered. The dial pointer shall be of sufficient length to reach the graduation marks; the width of the

TABLE 1 Permissible Variations of Specimen Molds

Parameter 50 mm Cube Molds 2 in. Cube Molds

New In Use New In Use

Planeness of sides <0.025 mm <0.05 mm <0.001 in. <0.002 in.

Distance between opposite sides 50 mm ± 0.13 mm 50 mm ± 0.50 mm 2 in. ± 0.005 in. 2 in. ± 0.02 in.

Height of each compartment 50 mm + 0.25 mm to −

0.13 mm

50 mm + 0.25 mm to −

0.38 mm

2 in. + 0.01 in. to −

0.005 in.

2 in. + 0.01 in. to −

0.015 in.

Angle between adjacent facesA 90° ± 0.5° 90° ± 0.5° 90° ± 0.5° 90° ± 0.5°

A Measured at points slightly removed from the intersection. Measured separately for each compartment between all the interior faces and the adjacent face and between interior faces and top and bottom planes of the mold.

C109/C109M − 24

Caleb Gunter (SOUTH CAROLINA STATE DEPT. OF TRANSPORTATION) pursuant to License Agreement. No further reproductions authorized.

Downloaded/printed by Copyright by ASTM Int'l (all rights reserved) Thu Oct 02 19:08:47 UTC 2025 end of the pointer shall not exceed the clear distance between the smallest graduations. Each dial shall be equipped with a zero adjustment that is easily accessible from the outside of the dial case, and with a suitable device that at all times until reset, will indicate to within 1 % accuracy the maximum load applied to the specimen.

5.9.1 If the testing machine load is indicated in digital form, the numerical display must be large enough to be easily read.

The numerical increment must be equal to or less than 0.10 % of the full scale load of a given loading range. In no case shall the verified loading range include loads less than the minimum numerical increment multiplied by 100. The accuracy of the indicated load must be within 1.0 % for any value displayed within the verified loading range. Provision must be made for adjusting to indicate true zero at zero load. There shall be provided a maximum load indicator that at all times until reset will indicate within 1 % system accuracy the maximum load applied to the specimen.

5.9.2 Compression machines shall be verified in accordance

with Practices E4 at least annually to determine if indicated loads, with and without the maximum load indicator (when so equipped), are accurate to 61.0 %.

NOTE 3—As close as can be read is considered 0.5 mm [0.02 in.] along the arc described by the end of the pointer. Also, one half of the scale interval is about as close as can reasonably be read when the spacing on the load indicating mechanism is between 1 mm [0.04 in.] and 1.6 mm [0.06 in.]. When the spacing is between 1.6 mm [0.06 in.] and 3.2 mm [0.13 in.], one third of the scale interval can be read with reasonable certainty. When the spacing is 3.2 mm [0.13] or more, one fourth of the scale interval can be read with reasonable certainty.

5.9.3 The upper bearing assembly shall be a spherically

seated, hardened metal block firmly attached at the center of the upper head of the machine. The center of the sphere shall coincide with the surface of the bearing face within a tolerance of 65 % of the radius of the sphere. Unless otherwise specified by the manufacturer, the spherical portion of the bearing block and the seat that holds this portion shall be cleaned and lubricated with a petroleum type oil such as motor oil at least every six months. The block shall be closely held in its spherical seat, but shall be free to tilt in any direction. A hardened metal bearing block shall be used beneath the specimen to minimize wear of the lower platen of the machine.

To facilitate accurate centering of the test specimen in the compression machine, one of the two surfaces of the bearing blocks shall have a diameter or diagonal of between 70.7 mm

[2.83 in.] (see Note 4) and 73.7 mm [2.9 in.]. When the upper block bearing surface meets this requirement, the lower block bearing surface shall be greater than 70.7 mm [2.83 in.]. When the lower block bearing surface meets this requirement, the diameter or diagonal of upper block bearing surface shall be between 70.7 mm and 79.4 mm [2.83 in. and 3.13 in.]. When the lower block is the only block with a diameter or diagonal between 70.7 mm and 73.7 mm [2.83 in. and 2.9 in.], the lower block shall be used to center the test specimen. In that case, the lower block shall be centered with respect to the upper bearing block and held in position by suitable means. The bearing block surfaces intended for contact with the specimen shall have a Rockwell harness number not less than 60 HRC. These surfaces shall not depart from plane surfaces by more than

0.013 mm [0.0005 in.] when the blocks are new and shall be maintained within a permissible variation of 0.025 mm

[0.001 in.].

5.9.3.1 Compression machine bearing blocks shall be

checked for planeness in accordance with this test method at least annually using a straightedge and feeler stock and shall be refinished if found to be out of tolerance.

NOTE 4—The diagonal of a 50 mm [2 in.] cube is 70.7 mm [2.83 in.].

6. Materials

6.1 Graded Standard Sand:

6.1.1 The sand (Note 5) used for making test specimens

shall be natural silica sand conforming to the requirements for graded standard sand in Specification C778.

NOTE 5—Segregation of Graded Sand—The graded standard sand should be handled in such a manner as to prevent segregation, since variations in the grading of the sand cause variations in the consistency of the mortar. In emptying bins or sacks, care should be exercised to prevent the formation of mounds of sand or craters in the sand, down the slopes of which the coarser particles will roll. Bins should be of sufficient size to permit these precautions. Devices for drawing the sand from bins by gravity should not be used.

7. Temperature and Humidity

7.1 Temperature—The temperature of the air in the vicinity

of the mixing slab, the dry materials, molds, base plates, and mixing bowl, shall be maintained between 23.0 °C 6 3.0 °C

[73.5 °F 6 5.5 °F]. The temperature of the mixing water, moist closet or moist room, and water in the storage tank shall be set at 23 °C 6 2 °C [73.5 °F 6 3.5 °F].

7.2 Humidity—The relative humidity of the laboratory shall

be not less than 50 %. The moist closet or moist room shall conform to the requirements of Specification C511.

8. Test Specimens

8.1 Make two or three specimens from a batch of mortar for

each period of test or test age.

9. Preparation of Specimen Molds

9.1 Apply a thin coating of release agent to the interior faces of the mold and non-absorptive base plates. Apply oils and greases using an impregnated cloth or other suitable means.

Wipe the mold faces and the base plate with a cloth as necessary to remove any excess release agent and to achieve a thin, even coating on the interior surfaces. When using an aerosol lubricant, spray the release agent directly onto the mold faces and base plate from a distance of 150 mm to 200 mm

[6 in. to 8 in.] to achieve complete coverage. After spraying, wipe the surface with a cloth as necessary to remove any excess aerosol lubricant. The residue coating should be just sufficient to allow a distinct finger print to remain following light finger pressure (Note 6).

9.2 Seal the surfaces where the halves of the mold join by

applying a coating of light cup grease such as petrolatum. The amount should be sufficient to extrude slightly when the two halves are tightened together. Remove any excess grease with a cloth.

9.3 Seal molds to their base plates with a watertight sealant.

Use microcrystalline wax or a mixture of three parts paraffin

C109/C109M − 24

Caleb Gunter (SOUTH CAROLINA STATE DEPT. OF TRANSPORTATION) pursuant to License Agreement. No further reproductions authorized.

wax to five parts rosin by mass. Paraffin wax is permitted as a sealant with molds that clamp to the base plate. Liquefy the wax by heating it to a temperature of between 110 °C and

120 °C [230 °F and 248 °F]. Effect a watertight seal by applying the liquefied sealant at the outside contact lines between the mold and its base plate (Note 7).

9.4 Optionally, a watertight sealant of petroleum jelly is

permitted for clamped molds. Apply a small amount of petroleum jelly to the entire surface of the face of the mold that will be contacting the base plate. Clamp the mold to the base plate and wipe any excess sealant from the interior of the mold and base plate.

NOTE 6—Because aerosol lubricants evaporate, molds should be checked for a sufficient coating of lubricant immediately prior to use. If an extended period of time has elapsed since treatment, retreatment may be necessary.

NOTE 7—Watertight Molds—The mixture of paraffin wax and rosin specified for sealing the joints between molds and base plates may be found difficult to remove when molds are being cleaned. Use of straight paraffin wax is permissible if a watertight joint is secured, but due to the low strength of paraffin wax it should be used only when the mold is not held to the base plate by the paraffin wax alone. When securing clamped molds with paraffin wax, an improved seal can be obtained by slightly warming the mold and base plate prior to applying the wax. Molds so treated should be allowed to return to room temperature before use.

10. Specimen Preparation Procedure

10.1 Composition of Mortars:

10.1.1 Materials for the standard mortar shall be cement, graded standard sand, and water. The quantities of materials to be mixed at one time in the batch of mortar for making six, nine, and twelve test specimens shall be in accordance with

Table 2. Use specified water content for all portland, portland-limestone, air-entraining portland, or air-entraining portland-limestone cements. The amount of mixing water for other cements shall be such as to produce a flow of 110 6 5 as determined in accordance with 10.3.

NOTE 8—The water-to-portland-cement and water-to-portland-limestone-cement ratio used in Table 2 is 0.485 by mass. For air-entraining cements, the water-to-portland-cement or water-to-portland-limestone-cement ratio is 0.460 by mass. The sand-to-cement ratio is 2.75.

10.2 Preparation of Mortar:

10.2.1 Mechanically mix in accordance with the procedure

given in Practice C305.

10.3 Determination of Flow:

10.3.1 Determine flow in accordance with procedure given

in Test Method C1437.

10.3.2 For portland, portland-limestone, air-entraining

portland, or air-entraining portland-limestone cements, record the flow.

10.3.3 In the case of cements other than portland, portland-

limestone, air-entraining portland, or air-entraining portland-limestone cements, make trial mortars with varying percent-ages of water until the specified flow is obtained. Make each trial with fresh mortar. Record the water content used to achieve the specified flow as weight percent of cement.

10.3.4 Immediately following completion of the flow test, return the mortar from the flow table to the mixing bowl.

Quickly scrape the bowl sides and transfer into the batch the mortar that may have collected on the side of the bowl and then remix the entire batch 15 s at medium speed. Upon completion of mixing, the mixing paddle shall be shaken to remove excess mortar into the mixing bowl.

10.3.5 When a duplicate batch is to be made immediately

for additional specimens, the flow test may be omitted and the mortar allowed to stand in the mixing bowl 90 s without covering. During the last 15 s of this interval, quickly scrape the bowl sides and transfer into the batch the mortar that may have collected on the side of the bowl. Then remix for 15 s at medium speed.

10.4 Molding Test Specimens:

10.4.1 Complete the consolidation of the mortar in the

molds either by hand tamping or by a qualified alternative method. Alternative methods include but are not limited to the use of a vibrating table or mechanical devices.

10.4.2 Hand Tamping—Start molding the specimens within

a total elapsed time of not more than 2 min and 30 s after completion of the original mixing of the mortar batch. Place a layer of mortar about 25 mm [1 in.] (approximately one half of the depth of the mold) in all of the cube compartments. Tamp the mortar in each cube compartment 32 times in about 10 s in four rounds, each round to be at right angles to the other and consisting of eight adjoining strokes over the surface of the specimen, as illustrated in Fig. 1. The tamping pressure shall be just sufficient to ensure uniform filling of the molds. The four rounds of tamping (32 strokes) of the mortar shall be completed in one cube before going to the next. When the tamping of the first layer in all of the cube compartments is completed, fill the compartments with the remaining mortar and then tamp as specified for the first layer. During tamping of the second layer, bring in the mortar forced out onto the tops of the molds after each round of tamping by means of the gloved fingers and the tamper upon completion of each round and before starting the next round of tamping. On completion of the tamping, the tops of all cubes should extend slightly above the tops of the molds. Bring in the mortar that has been forced out onto the tops of the molds with a trowel and smooth off the cubes by drawing the flat side of the trowel (with the leading

TABLE 2 Standard Test Mortar Proportions

Material Number of Specimens

6 9 12

Cement, g 500 740 1060

Sand, g 1375 2035 2915

Water, mL

Portland or portland-limestone cements 242 359 514

Air-entraining portland or air-entraining portland-limestone cements 230 340 488

Other cements (to flow of 110 ± 5)

C109/C109M − 24

Caleb Gunter (SOUTH CAROLINA STATE DEPT. OF TRANSPORTATION) pursuant to License Agreement. No further reproductions authorized.

edge slightly raised) once across the top of each cube at right angles to the length of the mold. Then, for the purpose of leveling the mortar and making the mortar that protrudes above the top of the mold of more uniform thickness, draw the flat side of the trowel (with the leading edge slightly raised) lightly once along the length of the mold. Cut off the mortar to a plane surface flush with the top of the mold by drawing the straight edge of the trowel (held nearly perpendicular to the mold) with a sawing motion over the length of the mold.

10.4.3 Alternative Methods—Any consolidation method

may be used that meets the qualification requirements of this section. The consolidation method consists of a specific procedure, equipment and consolidation device, as selected and used in a consistent manner by a specific laboratory. The mortar batch size of the method may be modified to accom-modate the apparatus, provided the proportions maintain the same ratios as given in 10.1.1.

10.4.3.1 Separate qualifications are required for the follow-ing classifications:

Class A, Non-air-entrained Cements—for use in concrete, such as sold under Specifications C150/C150M, C595/C595M, and C1157/C1157M.

Class B, Air-entrained Cements—for use in concrete, such as sold under Specifications C150/C150M, C595/C595M, and C1157/C1157M.

Class C, Masonry, Mortar, and Stucco Cements—such as sold under Specifications C91/C91M, C1328/C1328M, and

C1329/C1329M.

10.4.3.2 An alternative method may only be used to test the

cement types as given in 10.4.3.1 above, for which it has been qualified.

10.4.3.3 It can also be used for Strength Activity Index

determinations for fly ash and Slag Activity Index determina-tion for slag cement, such as sold under Specifications C618 and C989/C989M, provided the alternative method has quali-fied for both Class A and Class C cements.

10.4.4 Qualification Procedure—Contact CCRL to purchase

cement samples that have been used in the Proficiency Sample

Program (PSP). Four samples (5 kg each) of the class to be qualified will be required to complete a single qualification (see

Note 9).

10.4.4.1 In one day, prepare replicate six-cube or nine-cube

batches using one of the cements and cast a minimum of 36 cubes. Complete one round of tests on each cement on different days. Store and test all specimens as prescribed in the sections below. Test all cubes at the age of seven days.

10.4.4.2 Tabulate the compressive strength data and com-

plete the mathematical analyses as instructed in Annex A1.

10.4.5 Requalification of Alternate Compaction Method:

10.4.5.1 Requalification of the method shall be required if

any of the following occur:

(1) Evidence that the method may not be providing data in accordance with the requirements of Table 3.

(2) Results that differ from the reported final average of a

CCRL-PSP sample with a rating of 3 or less.

(3) Results that differ from the accepted value of a known reference sample with established strength values by more than twice the multi-laboratory 1s% values of Table 3.

Before starting the requalification procedure, evaluate all aspects of cube fabrication and testing process to determine if the offending result is due to some systematic error or just an occasional random event.

10.4.5.2 If the compaction equipment is replaced, signifi-

cantly modified, repaired, or has been recalibrated, requalify the equipment in accordance with 10.4.4.

NOTE 9—It is recommended that a large homogenous sample of cement be prepared at the time of qualification for use as a secondary standard and for method evaluation. Frequent testing of this sample will give early warning of any changes in the performance of the apparatus.

10.5 Storage of Test Specimens—Immediately upon

completion of molding, place the test specimens in the moist closet or moist room. Keep all test specimens, immediately after molding, in the molds on the base plates in the moist closet or moist room from 20 h to 72 h with their upper surfaces exposed to the moist air but protected from dripping water. If the specimens are removed from the molds before

24 h, keep them on the shelves of the moist closet or moist room until they are 24-h old, and then immerse the specimens, except those for the 24-h test, in saturated lime water in storage tanks constructed of noncorroding materials. Keep the storage water clean by changing as required.

11. Determination of Compressive Strength

11.1 Test the specimens immediately after their removal

from the moist closet in the case of 24-h specimens, and from storage water in the case of all other specimens. All test specimens for a given test age shall be broken within the permissible tolerance prescribed as follows:

Test Age Permissible Tolerance

24 h ±1⁄2 h

3 day ±1 h

7 day ±3 h

28 day ±12 h

If more than one specimen at a time is removed from the moist closet for the 24-h tests, keep these specimens covered with a damp cloth until time of testing. If more than one specimen at a time is removed from the storage water for testing, keep these specimens in water at a temperature of

23 °C 6 2 °C [73.5 °F 6 3.5 °F] and of sufficient depth to completely immerse each specimen until time of testing.

11.2 Wipe each specimen to a surface-dry condition, and

remove any loose sand grains or incrustations from the faces that will be in contact with the bearing blocks of the testing

FIG. 1 Order of Tamping in Molding of Test Specimens

C109/C109M − 24

Caleb Gunter (SOUTH CAROLINA STATE DEPT. OF TRANSPORTATION) pursuant to License Agreement. No further reproductions authorized.

machine. Check these faces by applying a straightedge (Note

10). If there is appreciable curvature, grind the face or faces to plane surfaces or discard the specimen.

NOTE 10—Specimen Faces—Results much lower than the true strength will be obtained by loading faces of the cube specimen that are not truly plane surfaces. Therefore, it is essential that specimen molds be kept scrupulously clean, as otherwise, large irregularities in the surfaces will occur. Instruments for cleaning molds should always be softer than the metal in the molds to prevent wear. In case grinding specimen faces is necessary, it can be accomplished best by rubbing the specimen on a sheet of fine emery paper or cloth glued to a plane surface, using only a moderate pressure. Such grinding is tedious for more than a few hundredths of a millimeter (thousandths of an inch); where more than this is found necessary, it is recommended that the specimen be discarded.

11.3 Apply the load to specimen faces that were in contact

with the true plane surfaces of the mold. Carefully place the specimen in the testing machine below the center of the upper bearing block. Prior to the testing of each cube, it shall be ascertained that the spherically seated block is free to tilt. Use no cushioning or bedding materials. Bring the spherically seated block into uniform contact with the surface of the specimen. Apply the load rate at a relative rate of movement between the upper and lower platens corresponding to a loading on the specimen with the range of 900 N ⁄s to 1800 N/s

[200 lbf ⁄s to 400 lbf/s]. Obtain this designated rate of move-ment of the platen during the first half of the anticipated maximum load and make no adjustment in the rate of move-ment of the platen in the latter half of the loading especially while the cube is yielding before failure.

NOTE 11—It is advisable to apply only a very light coating of a good quality, light mineral oil to the spherical seat of the upper platen.

12. Calculation

12.1 Record the total maximum load indicated by the testing

machine, and calculate the compressive strength as follows:

fm 5 P/A (1) where:

fm = compressive strength in MPa [psi], P = total maximum load in N [lbf], and A = area of loaded surface mm2 [in.2].

Either 50 mm [2 in.] cube specimens may be used for the determination of compressive strength, whether inch-pound or

SI units are used. However, consistent units for load and area must be used to calculate strength in the units selected. If the cross-sectional area of a specimen varies more than 1.5 % from the nominal, use the actual area for the calculation of the compressive strength. The compressive strength of all accept-able test specimens (see Section 13) made from the same sample and tested at the same period shall be averaged and reported to the nearest 0.1 MPa [10 psi].

TABLE 3 Precision

Test Age, days

Coefficient of Variation, 1s%A

Acceptable

Range of Test

Results, d2s%A

Portland Cements

Constant water-cement ratio:

Single laboratory 1 3.1 8.7

3 3.9 10.9

7 3.9 10.9

28 3.8 10.6

Average . . . 3.7 10.4

Multiple laboratories 1 7.3 20.4

3 6.8 19.0

7 6.6 18.5

28 6.5 18.2

Average . . . 6.6 18.5

Blended Cements (Excluding Portland-limestone Cements)

Constant flow mortar:

Single laboratory 3 4.0 11.3

7 3.8 10.7

28 3.4 9.6

Average . . . 3.8 10.7

Multiple laboratories 3 7.8 22.1

7 7.6 21.5

28 7.4 20.9

Average . . . 7.6 21.5

Masonry Cements

Constant flow mortar:

Single laboratory 7 7.9 22.3

28 7.5 21.2

Average . . . 7.7 21.8

Multiple laboratories 7 11.8 33.4

28 12.0 33.9

Average . . . 11.9 33.7

A These numbers represent, respectively, the (1s%) and (d2s%) limits as de-scribed in Practice C670.

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13. Report

13.1 Report the flow to the nearest 1 % and the water used

to the nearest 0.1 %. Average compressive strength of all specimens from the same sample shall be reported to the nearest 0.1 MPa [10 psi].

14. Faulty Specimens and Retests

14.1 In determining the compressive strength, do not con-

sider specimens that are manifestly faulty.

14.2 The maximum permissible range between specimens

from the same mortar batch, at the same test age is 8.7 % of the average when three cubes represent a test age and 7.6 % when two cubes represent a test age (Note 12).

NOTE 12—The probability of exceeding these ranges is 1 in 100 when the within-batch coefficient of variation is 2.1 %. The 2.1 % is an average for laboratories participating in the portland cement and masonry cement reference sample programs of the Cement and Concrete Reference Laboratory.

14.3 If the range of three specimens exceeds the maximum

in 14.2, discard the result which differs most from the average and check the range of the remaining two specimens. Make a retest of the sample if less than two specimens remain after discarding faulty specimens or discarding tests that fail to comply with the maximum permissible range of two speci-mens.

NOTE 13—Example for Permissible Range—For a data set of three cubes (31.0 MPa, 34.0 MPa, and 35.0 MPa) the average strength is

33.3 MPa with a range of 4.0 MPa. According to the 8.7% limit, the range should not be more than 2.9 MPa (33.3 × 0.087). Since the range here is greater than 2.9 MPa, discard the value most different from the average, in this case 31.0 MPa. Now, the new average based on only two specimens is 34.5 MPa and the range should not be more than 2.6 MPa (34.5 × 0.076). Since the difference between the two values is less than the range this is an acceptable data set and the reported average should be 34.5 MPa.

NOTE 14—Reliable strength results depend upon careful observance of all of the specified requirements and procedures. Erratic results at a given test period indicate that some of the requirements and procedures have not been carefully observed; for example, those covering the testing of the specimens as prescribed in 11.1 and 11.2. Improper centering of speci-mens resulting in oblique fractures or lateral movement of one of the heads of the testing machine during loading will cause lower strength results.

15. Precision and Bias

15.1 Precision4—The precision statements for this test

method are listed in Table 3 and are based on results from the

Cement and Concrete Reference Laboratory Reference Sample

Program (see Note 15). They are developed from data where a test result is the average of compressive strength tests of three cubes molded from a single batch of mortar and tested at the same age (see Note 16).

NOTE 15—The Precision and Bias statement for this test method applies only to the measured strength of mortars prepared following the provi-sions of this test method and using cements specified under Specifications C91/C91M, C150/C150M, C595/C595M, C1328/C1328M, and C1329/ C1329M.

NOTE 16—A significant change in precision would not be anticipated when a test result is the average of two cubes rather than three.

NOTE 17—The test results used to determine the precision and bias for this test method were obtained using the in-lb units provided in this standard.

15.2 These precision statements are applicable to mortars

made with cements mixed and tested at the ages as noted.

15.3 Bias—The procedure in this test method has no bias

because the value of compressive strength is defined in terms of the test method.

16. Keywords

16.1 compressive strength; hydraulic cement mortar; hy-draulic cement strength; mortar strength; strength

ANNEX

(Mandatory Information)

A1. ANALYSES OF TEST RESULTS FOR QUALIFICATION OF ALTERNATE COMPACTION METHODS

A1.1 Calculation of Average Within-Batch Standard

Deviation and Elimination of Outliers—Tabulate the results for each cement sample (or round) in separate spread-sheets. In the spreadsheet, list results of each batch in columns and complete the calculations as shown in Table A1.1.

A1.1.1 Eliminate any outliers from the test data and repeat the calculations until none of the values lie outside the normal range.

A1.1.2 Tabulate the cube strengths with all the outliers eliminated and complete the calculations as shown in Table

A1.2.

A1.2 Summary of Results—Compile the results of the four rounds and complete the calculations as shown in Table A1.3.

The number of outliers shall not exceed 5 % of the total number of tests when rounded to the nearest whole number (for example, 4 rounds × 4 batches × 9 cubes = 144 tests ×

(5 % ⁄100) = 7.2 or 7).

A1.3 Precision Qualification—Calculate the relative within batch error (RWBE %) as shown in Table A1.3. This value must be less than 2.1 % to comply with the limit established in

Note 12 of this specification.

4 Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:C01-1011. Contact ASTM Customer

Service at www.astm.org/contact.

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A1.4 Bias Qualification—The test results compiled in Table

A1.3 are evaluated against three limits to demonstrate an acceptable qualification. The limits have been established statistically from analyses of historical CCRL data and are given in Table A1.4.

A1.5 Rationale for Limits Given in A1.4:

A1.5.1 The multi-laboratory precision (1s%) for the average of n batches is given by:

s%ML,n 5Œs%ML

2 S 1 2 n D s%SO

A1.5.2 The limit for deviation of the individual rounds (no failures being allowed when four rounds are performed) is

1.2s%ML,n, as used in Test Methods C114.

A1.5.3 The multi-laboratory precision (1s%) for the mean of four rounds is 0.5s%ML,n.

A1.5.4 The limit for deviation of the mean of four rounds

(95 % confidence) is 1.96 times this, or 0.98s%ML,n.

A1.5.5 The values for s%ML and s%SO for Cement Classes

A and C (non-air-entrained cements for concrete and cements for mortar respectively) are the seven-day values in the current precision statement of Test Method C109/C109M. There ap-pears to be no data for Cement Class B (air-entrained cements for concrete). Working on the assumption that the value of this quantity is related to the air content, the values adopted for

Class B are the mean of the A and C values.

A1.5.6 For the applicable conditions, the equations above give the following:

Derivation of Limits for Table A1.4

Cement Class A B C A B C

Batches per Round (n) 6 6 6 4 4 4

Single Operator s%

(single batch)

3.6 5.75 7.9 3.6 5.75 7.9

Multi-Laboratory s%

(single batch)

6.4 9.1 11.8 6.4 9.1 11.8

Multi-Laboratory s%

(n batches)

5.5 7.4 9.3 5.6 7.6 9.6

Limit for deviation of a single round %

6.6 8.9 11.2 6.7 9.1 11.5

Limit for deviation of mean of four rounds %

5.4 7.3 9.2 5.5 7.5 9.4

TABLE A1.1 Example Using 9-cube Batch

Round – 2

CCRL Sample #140 Industry Average

Strength, Xi = 32.923

Cast Date – 00/00/00

7-day Strengths, MPa

A B C D E

Batch No. 1 2 3 4

Cube 1 33.0 34.3 34.4 33.2

Cube 2 33.9 32.5 34.0 34.0

Cube 3 33.4 34.0 34.1 33.8

Cube 4 33.1 33.8 34.0 33.8

Cube 5 33.0 33.4 34.2 34.0

Cube 6 32.8 33.7 31.8 33.1

Cube 7 33.6 32.6 33.9 32.8

Cube 8 31.5 32.1 33.0 33.3

Cube 9 33.6 34.3 33.4 34.4

Average, Xb 33.10 33.42 33.65 33.60

SDb 0.70 0.82 0.81 0.52

Nb 9 9 9 9

(Nb−1)SDb 2 3.936 5.432 5.265 2.145

Nr 36

Xr 33.44

SDr 0.692

MND 1.703

Normal Range

Maximum 34.81 35.12 35.35 35.30

Minimum 31.40 31.71 32.95 31.89

Outliers None None Cube 6 None where:

Xi = industry average strength (CCRL), Xb = average of tests values in a single batch, SDb = standard deviation of a single batch, Πo Cube sX2Xbd2

Nb21

Nb = number of tests per batch, (Nb−1)SDb 2 = an intermediate calculation, Nr = total number of tests per round, Xr = grand average of tests values obtained per round, MPa, SDr = mean standard deviation of round, Œ o Batch fsNb21dSDb 2g

N r21

MND = maximum normal deviation: use ExcelA function “=norminv(1−0.25/Nr,0,SDr)” or equivalent, or use statistical tables to find the inverse integrated normal distri-bution for an integral value of (1−0.25/nr) in a normal distribution with σ = SDr, Normal Range, Maximum = (Xb + MND), Normal Range, Minimum = (Xb − MND), and

Outlier = any test value falling outside the calcu-lated normal range.

A Excel is a registered trademark of Microsoft Corporation in the United States and other countries.

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TABLE A1.2 Test Data After Elimination of Outliers (Example Using 9-cube Batch)

Round – 2

CCRL Sample #140 Industry Average

Strength, Xi = 32.923

Cast Date – 00/00/00 Raw Cube Data:

7-day Strengths, MPa

A B C D E

Batch No. 1 2 3 4

Cube 1 33.0 34.3 34.4 33.2

Cube 2 33.9 32.5 34.0 34.0

Cube 3 33.4 34.0 34.1 33.8

Cube 4 33.1 33.8 34.0 33.8

Cube 5 33.0 33.4 34.2 34.0

Cube 6 32.8 33.7 33.1

Cube 7 33.6 32.6 33.9 32.8

Cube 8 32.1 33.0 33.3

Cube 9 33.6 34.3 33.4 34.4

Average, Xbv 33.29 33.42 33.89 33.60

SDbv 0.39 0.82 0.46 0.52

Nbv 8 9 8 9

(Nbv−1)SDbv 2 1.092 5.348 1.462 2.159

Nrv 34

Xrv 33.55

Xi 32.92

SDrv 0.55

Er, MPa 0.63

REr, % 1.91 where:

Xbv = average of valid test values obtained per batch, MPa, Xi = industry average strength (CCRL), MPa, SDbv = Πo ValidCube sX2Xbvd

Nbv21

Nbv = number of valid tests per batch, (Nbv-1)SDbv 2 = an intermediate calculation, Nrv = total number of valid tests of the round, Xrv = grand average of valid tests for the round, MPa, SDrv = mean standard deviation of the round, Πo Batch fsNbv21dSDbv 2 g

N rv21

Er = error = (Xi – Xrv), MPa, and

REr = relative error for the round, % = 100(Er/Xrv).

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TABLE A1.3 Summary of Results

A B C D E F G H I

CCRL

Day Xi, MPa Xrv, MPa REr, % Nrv SDrv (Nr−1)SDr

Round 1 139 1 28.47 30.42 6.85 36 0.97 32.93

Round 2 140 2 32.92 33.55 1.91 34 0.55 9.98

Round 3 141 3 32.64 33.14 1.53 34 0.47 7.29

Round 4 142 4 32.24 33.01 2.39 36 0.51 9.10

Max, REr, % 6.85

Mean, REr, % 3.17

GMWBE, MPa 0.65

RWBE, % 2.01

Max RWBE, %A 2.1

Precision Test Pass where:

Xr = industry average strength, MPa, Xrv = grand mean value of the valid tests of a round, RErv, % = relative error = 100(Xi − Xrv), Nrv = total number of valid tests of the round, SDrv = mean standard deviation of a round, Œ o Batch fsNbv21dSDrv 2 g

N rv21

(Nr−1)SDr 2 = intermediate calculation, Xg = grand mean value of all valid tests (four rounds), Ng = total number of valid tests in four rounds, GMWBE = grand mean within-batch error, MPa, Œ o Round fsN rv21dSDrv 2 g

Ng21

RWBE = relative within batch error, % = 100(GMWBE / Xg), and

Max RWBE = maximum allowed RWBE = 2.10 % (see Note 12).

A See Note 11.

TABLE A1.4 Bias Qualification Requirements

6-cube Batches

(Minimum 6 Batches per Round)

9-cube Batches

(Minimum 4 Batches per Round)

Cement Classification (see 10.4.3.1) A B C A B C

Max allowable relative error any 4 or 6 batches, MAREr % 6.6 8.9 11.2 6.7 9.1 11.5

Max allowable relative error mean of 4 rounds of 4 or 6 batches <5 % failures, GRE % 5.4 7.3 9.2 5.5 7.5 9.4

Minimum allowable confidence limit, %, MACL % 95 95 95 95 95 95

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SUMMARY OF CHANGES

Committee C01 has identified the location of selected changes to this standard since the last issue

(C109/C109M – 23) that may impact the use of this standard. (Approved Oct. 15, 2024.)

(1) Revised 5.3 for clarity.

(2) Revised 5.6 to have the correct significant digits.

(3) Added Note 17.

Committee C01 has identified the location of selected changes to this standard since the last issue

(C109/C109M – 21) that may impact the use of this standard. (Approved Dec. 15, 2023.)

(1) Changed the standard throughout to make SI units the primary units and inch-pound units as the alternative units.

TABLE A1.5 Bias Tests (Example Using 9-cube Batches, Class A Cement)

NOTE 1—The qualification method fails for bias if (1) the MREr exceeds the MAREr, % limit; or if (2) the GRE, % exceeds the MGREg limit and the CL, % exceeds 95 %.

MREr %, the maximum relative error value of the four rounds 6.85

MAREr %, max allowable MREr from Table A1.4 6.7

Fails

GRE %, the average REr % of the four rounds 3.13

Maximum limit of MGREg % from Table A1.4 5.5

Pass

Bias confidence limit, CL % 96.99

Minimum allowable confidence limit, MACL % (from Table A1.4) 95

Pass

The above results indicate the data fails to show compliance.

where:

MREr, % = the maximum relative error, % obtained for any round (from values in column F, Table A1.3), MAREr, % = the maximum allowable relative error, % of any round (Table

A1.4), GRE, % = the grand average of the REr, % values of the four rounds, MAREg, % = maximum allowed GRE, % value (average of column F, Table A1.3), and

CL, % = bias confidence limit, %, the confidence with which it can be stated that the error of the mean of four rounds is non-zero.

Calculate this by use of ExcelA function “=ttest(<range of industry means>,<range of values obtained>,1,1)” or equivalent, or use statistical tables to find the confidence in a one-tailed, paired-value t-test on the set of round errors.

A Excel is a registered trademark of Microsoft Corporation in the United States and other countries.

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