ASTM C1810/C1810M-23

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: C1810/C1810M − 22 C1810/C1810M − 23
Standard Guide for
Comparing Performance of Concrete-Making Materials
Using Mortar Mixtures
This standard is issued under the fixed designation C1810/C1810M; 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*
1.1 This guide provides information on how to compare the relative performance and potential incompatibility of combinations
of concrete-making materials. Performance tests on fresh and early-age properties of mortar mixtures can be useful indicators of
concrete performance using similar materials. The performance tests described in this guide include mortar-slump, mortar spread,
mortar-workability retention, early stiffening of mortar, time of setting, air entrainment, and hydration kinetics.
1.2 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. 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 non-conformance with this guide. Some values only have SI units because the inch-pound
equivalents are not used in guide.
1.3 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. Warning—Fresh hydraulic cementitious mixtures are caustic and may cause burns to skin and
tissue upon prolonged exposure.
1.4 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:
C70 Test Method for Surface Moisture in Fine Aggregate
C125 Terminology Relating to Concrete and Concrete Aggregates
C128 Test Method for Relative Density (Specific Gravity) and Absorption of Fine Aggregate
C185 Test Method for Air Content of Hydraulic Cement Mortar
C219 Terminology Relating to Hydraulic and Other Inorganic Cements
C305 Practice for Mechanical Mixing of Hydraulic Cement Pastes and Mortars of Plastic Consistency
C359 Test Method for Early Stiffening of Hydraulic-Cement (Mortar Method)
C403/C403M Test Method for Time of Setting of Concrete Mixtures by Penetration Resistance
C494/C494M Specification for Chemical Admixtures for Concrete
This guide is under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregates and is the direct responsibility of Subcommittee C09.48 on
Performance of Cementitious Materials and Admixture Combinations.
Current edition approved Dec. 15, 2022Oct. 1, 2023. Published February 2023November 2023. Originally approved in 2019. Last previous edition approved in 20212022
as C1810/C1810M – 21a.C1810/C1810M – 22. DOI: 10.1520/C1810_C1810M-22.10.1520/C1810_C1810M-23.
Section on Safety Precautions, Manual of Aggregate and Concrete Testing, Annual Book of ASTM Standards, Vol. 04.02.
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
C1810/C1810M − 23
C566 Test Method for Total Evaporable Moisture Content of Aggregate by Drying
C670 Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
C778 Specification for Standard Sand
C1602/C1602M Specification for Mixing Water Used in the Production of Hydraulic Cement Concrete
C1679 Practice for Measuring Hydration Kinetics of Hydraulic Cementitious Mixtures Using Isothermal Calorimetry
C1777 Test Method for Rapid Determination of the Methylene Blue Value for Fine Aggregate or Mineral Filler Using a
Colorimeter
E11 Specification for Woven Wire Test Sieve Cloth and Test Sieves
E2251 Specification for Liquid-in-Glass ASTM Thermometers with Low-Hazard Precision Liquids
IEEE/ASTM SI 10 American National Standard for Metric Practice
2.2 ISO Standard:
ISO 679 Cement–Test Methods–Determination of Strength
3. Terminology
3.1 Definitions—For definitions of terms used in this guide, refer to Terminology C125 and Terminology C219.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 admixture-induced early stiffening, n—early stiffening of a cementitious mixture brought about by the addition of a chemical
admixture.
3.2.2 delayed addition of admixture—addition of admixture at least one minute after the initial mixing of cementitious materials
and water.
3.2.3 mortar-slump—vertical distance between the original and displaced position of the center of the top surface of mortar when
tested with the mortar-slump mold.
3.2.4 mortar-slump retention time—the duration of time over which the mortar mixture maintains at least 50 % of its initial
mortar-slump.
3.2.5 mortar-spread—distance of lateral flow of mortar from the mortar-slump test.
3.2.6 up-front addition of admixture—concurrent addition of admixture with the mixing water to the dry materials of the mortar
mixture.
3.2.7 workability index—relative indicator of workability calculated as the sum of the mortar-slump and mortar spread minus 100
for measurements in SI units, and minus 4 for measurements in inch-pound units.
4. Significance and Use
4.1 The results of mortar mixture tests can be suitable for comparing the relative performance of combinations of concrete-making
materials such as fine aggregate, chemical admixtures, supplementary cementitious materials (SCMs), water, and hydraulic
cement. Furthermore, this guide can be useful to identify unexpected performances due to combination of various materials. The
relative trends in performance observed with the mortar method may suggest relative performance in concrete mixtures batched
with the same materials and relative mixture proportions.
4.2 While there are a number of ways to proportion and mix mortar mixtures, threefour procedures described in this guide have
been used extensively for evaluating the performance of admixtures. Method A enables evaluation of materials using mixture
proportions that correspond to specific job conditions. Method B can be used as a general mixture using fixed amounts of a standard
sand, cement, and supplementary cementitious materials. Method C is a modified version of Test Method C359 to evaluate the
impact of chemical admixtures on the early stiffening of a mortar prepared with specified amounts of job cement, a standard sand,
and an amount of water that will produce a mortar with a specified initial penetration measured in accordance with Test Method
C359. The measurements of penetration over time can be related to the early stiffening processes associated with false and flash
Available from International Organization for Standardization (ISO), ISO Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva,
Switzerland, http://www.iso.org.
C1810/C1810M − 23
set. Method D is a modified version of Test Method C185 whereby the mortar mixture can be prepared with various combinations
of chemical admixtures, supplementary cementitious materials, and job water. Methods A and B would be most applicable for
investigating material incompatibility issues associated with ready mixed concrete, while Method C would be applicable for
concrete mixed for a short period of time in stationary mixers and transported to the forms in non-agitating equipment. Method
D is suitable for all concrete mixing processes and is most applicable if the focus of a material incompatibility issue is unexpected
changes in air content.
5. Apparatus
5.1 The following equipment is used for the mortar preparation and testing:
5.1.1 Mixer with Paddle and Bowl—A table-mounted mixer meeting the requirements of Practice C305.
NOTE 1—Similar mixers with larger capacity are acceptable if the same mixer is used for preparing all mixtures that will be compared.
5.1.2 Timer, able to measure a total time of at least 60 min with an accuracy of 1 s.
5.1.3 Scraper, consisting of a rubber blade attached to a handle about 150 mm [6 in.] in length, with a blade of about 75 mm long
[3 in.], 50 mm [2 in.] wide, and tapered to a thin edge about 2 mm [0.08 in.] thick.
NOTE 2—A kitchen tool known as a plate and bowl scraper may conform to these requirements.
5.1.4 Balance, of sufficient capacity to measure the mass of materials to the nearest 0.5 g.
5.1.5 Spoon and Tamper—Conforming to Test Method C185.
5.1.6 Pointed Mortar Trowel—Having a steel blade 100 to 150 mm [4 to 6 in.] long with straight edges. The edges when placed
on a plane surface shall not depart from straightness by more than 1 mm [0.04 in.].
5.1.7 Plastic Syringes (without needles), 1 to 250 mL capacity, with markings readable to 65 % of capacity.
5.1.8 Mortar-slump Mold—With a top opening of 50 mm [2 in.], bottom opening of 100 mm [4 in.], a height of 150 mm [6 in.],
and wall thickness of at least 2 mm [0.08 in.]. The tolerance for height and diameter is 62 mm [ ⁄16 in.].
5.1.9 Plastic Ring, 12.5 mm [ ⁄2 in.] thick by 250 mm [10 in.] diameter with a 70 mm [2.75 in.] diameter hole in the center.
NOTE 3—The ring fits over the mortar-slump mold to hold the mold on to the base plate and to catch mortar overflowing as it is added to the mold.
5.1.10 Funnel—The mold described in Test Method C128 or other suitable funnel for filling mortar-slump mold.
5.1.11 Base Plate—Square, non-absorbent, at least 300 mm [12 in.]. The plate shall be sufficiently flat so that there is no leakage
of mortar at the base of the slump mold during the filling process.
5.1.12 Steel Tamping Rod, 9.5 mm [ ⁄8 in.] diameter by 300 mm [12 in.] long with rounded ends.
5.1.13 Ruler, at least 300 mm [12 in.] long.
5.1.14 Calipers, 300 mm [12 in.] readable to 1 mm [0.05 in.].
5.1.15 Nominal 400 mL Brass Cup, or similar size container with a known volume.
5.1.16 16 mm [ ⁄8 in.] diameter Tapping Stick, made of hard wood, 150 mm [6 in.]) in length.
The sole source of supply of the apparatus known to the committee at this time is Certified Material Testing Products, Palm Bay, Fl., under the name, Mini Steel Slump
Cone. If you are aware of alternative suppliers, please provide this information to ASTM International Headquarters. Your comments will receive careful consideration at
a meeting of the responsible technical committee, which you may attend.
C1810/C1810M − 23
5.1.17 Sieve, 4.75 mm (No. 4) as described in Specification E11.
5.1.18 Thermometer—The thermometer shall be capable of measuring the temperature of the fresh mortar to 6 0.5 °C [61 °F].
ASTM liquid-in-glass thermometers having a temperature range from −20 °C to 50 °C [ 0 °F to 120 °F], and conforming to the
requirements of Thermometer 97F (or 97C) as prescribed in Specification E2251 are satisfactory. Other thermometers of the
required accuracy, including the metal immersion type, are acceptable.
6. Mortar Mixture Proportions—Methods A and B
6.1 Two methods are described for proportioning mortar mixtures. Method A is adapted from specific job mixture proportions, and
Method B is based on fixed proportions, which can be suitable for the evaluation of various concrete-making materials other than
coarse aggregate. Make multiple batches of mortar using the same mixture proportions to provide sufficient material to perform
all the required tests.
6.1.1 Method A, Mortar Proportioned Based on Job Concrete Mixture Proportions:
6.1.1.1 Express the proportions of the concrete materials of the job mixture in SI units of kg/m as quantities suitable for the mortar
mixture by multiplying the masses of cement, supplementary cementitious material (SCM) (if used), sand at saturated-surface-dry
(SSD) condition, and water by a factor of 3. (Multiplying the mixture components by a factor of 3 results in a mortar batch having
volume sufficient to perform a number of tests.) Omit the coarse aggregate. The resulting quantities are in units of gram and mL
and represent the batch proportions. Increase or decrease the factor as necessary to provide the amount of the mortar needed for
the intended tests and the capacity of the mixer. Do not overload the mixer. If additional mortar is needed, make additional batches
or use a larger mixer. If the concrete mixture proportions are reported in inch-pound units, first convert to SI units. Obtain
proportions in SI units by measurement in SI units or by appropriate conversion, using the Rules for Conversion and Rounding
given in IEEE/ASTM SI 10 for measurements made in other units.
C1810/C1810M − 23
NOTE 4—As an example, a concrete mixture proportioned in inch-pound units is converted to a mortar mixture as shown in the table below:
Concrete Mixture Proportions
Mortar Mixture
Material Proportions
inch-pound units SI units
3 3 A
SI units, g
(lb/yd ) (kg/m )
B
Cement 517 307 921
B
Fine Aggregate 1244 738 2214
Coarse Aggregate 1845 1096 Omit
B
Water 251 149 447
C D E
MRWR 7.6 oz/100 lb 496 mL/100 kg 4.6 mL
F E
AEA 0.2 oz/100 lb 13.0 mL/100 kg 0.12 mL
F
Dilute 1/100 12.0 mL
A 3
lb ⁄cy × 0.5933 = kg/m .
B 3
Mixture proportion, kg/m × 3 expressed as grams.
C
MRWR—midrange water reducer.
D
fl oz/100 lb × 65.2 = mL/100 kg.
E
(mL ⁄100 kg × 0.921 kg)/100 = mL for mortar mixture.
F
Air-entraining admixture (AEA). Diluting the AEA by a factor of 100 provides a measurable quantity.
6.1.2 Method B, Mortar Proportioned Based on Mortar Fraction of Specification C494/C494M Concrete Mixture:
6.1.2.1 Prepare the reference mortar mixture with 600 g 6 5 g of cementitious material, 1350 g 6 5 g of one of the following
sand: (a) standard sand conforming to ISO 679; (b) a blend of 675 g 6 3 g of graded sand and 675 g 6 3 g of 20-30 sand
conforming to Specification C778, or (c) an alternative sand such as the job sand. Add sufficient water to obtain a mortar-slump
of 50 mm to 125 mm [2 in. to 5 in.].
NOTE 5—A stock concrete sand may be used for Method B.
6.2 For subsequent mixtures prepared by either by Method A or Method B, partially or totally replace materials in the reference
mortar mixture to test the effect of these materials on selected mortar properties such as mortar-slump, mortar-slump retention, time
of setting, and air content.
6.3 If a chemical admixture is to be used, measure the amount of admixture by volume or mass. If measuring by volume, use a
syringe of sufficient volume. If comparing the performance of chemical admixtures with different oven-dried residue contents,
compare their performance based on either an equal oven-dried residue content by mass of cement or equal volume by mass of
cement.
NOTE 6—Adding the correct amount of a low-dosage chemical admixture, such as an air-entraining admixture, is facilitated by first diluting the admixture
by a factor of 10 to 100. Include the water from the diluted admixture in the total water content of the mortar mixture proportions.
7. Sand Preparation
7.1 For Method A, use job proportions and job sand. For method B, use sand meeting one of the requirements in 6.1.2.1.
7.1.1 For the standard sand conforming to ISO 679 or the blend of 675 g 6 3 g of graded sand and 675 g 6 3 g of 20-30 sand
conforming to Specification C778, determine the relative density (specific gravity) for the SSD condition and absorption of the
sand in accordance with Test Method C128. Use the absorption value to determine the quantity of water to be added to the mortar
mixture to bring the sand to the SSD condition.
7.2 For alternative sand sources, prepare the sand as follows:
7.2.1 For concrete sand, pass the sand through a 4.75 mm (No. 4) sieve.
NOTE 7—Sieve size is identified by its standard designation in Specification E11.
NOTE 8—Particles larger than 4.75 mm can cause possible damage to the mixer shaft.
7.2.2 Blend the sieved sand and protect it from moisture evaporation during the measuring and batching sequence.
C1810/C1810M − 23
7.2.3 Determine the relative density (specific gravity) SSD and absorption of the sand in accordance with Test Method C128.
7.2.4 Determine the free moisture content of the sand in accordance with either Test Method C70 or C566, and adjust the masses
of sand and water to be added accordingly. If sand is drier or wetter than the SSD condition, correct for absorbed or excess moisture
in the mortar mixture proportions.
7.2.5 Measure the mass of the sand required for each batch, place the sand into a container, and keep the container covered with
an airtight lid until time of mixing.
7.3 For tests to be performed at 23.0 °C 6 2.0 °C [73 °F 6 3 °F], store all the materials at 23.0 °C 6 2.0 °C [73 °F 6 3 °F] for
sufficient time to equilibrate within that temperature range prior to the start of mixing.
7.4 For mixing to be performed at other temperatures, allow all the materials to equilibrate at that temperature prior to mixing.
8. Batching and Mixing
8.1 Measure the mass of the water and cementitious materials required for each batch.
8.1.1 Potable water, as defined in Specification C1602/C1602M, shall be used as the reference water when evaluating job mixing
water.
8.2 To evaluate admixtures under up-front batching condition, add the required admixture to the mixing water. Stir the solution
to disperse the admixture. Add admixtures that are not compatible in concentrated form, such as solutions of calcium salts and
certain air-entraining and set retarding admixtures, separately during the batching procedure.
8.3 Before the addition of materials, dampen the mixing bowl and paddle by wiping down with a wet paper towel.
8.4 Add all sand to the mixing bowl followed by the cementitious materials.
8.5 Mix for 10 s at slow speed, 140 rpm 6 5 rpm.
8.6 To test delayed addition of admixtures, add the admixture (or the diluted solution of admixture) 1 min after the dry material
comes in contact and is mixed with the batch water.
8.7 With the mixer operating at slow speed, add the entire amount of mixing water within 5 s. Start the timer, and record the time
when the water is added.
8.8 Once all the water is added, stop the mixer and change to medium speed, 285 rpm 6 10 rpm.
8.9 Continue mixing for 5 min, then stop the mixer.
8.10 Scrape the bottom and sides of the bowl and mix any dry material by hand into the bulk mortar for 30 s. Let the mortar remain
undisturbed until the 8 min mark.
8.11 At the 8 min mark, start mixing for 1 min at medium speed, 285 rpm 6 10 rpm. Stop the mixer, remove the paddle, measure
and record the mortar temperature, and measure the mortar slump in accordance with 9.1.
8.12 If the mortar-slump is less than 50 mm [2 in.] or greater than 125 mm [5 in.], discard the batch, and make a new mortar
mixture with a lower or higher amount of water, as appropriate.
8.13 If mortar-slump retention is to be determined, return the mortar used for the mortar-slump and air content tests to the mixing
C1810/C1810M − 23
bowl, and continue mixing at slow speed for 15 min increments, stopping to perform mortar-slump, mortar-spread, air content, and
the temperature of the mortar after each 15 min period. Continue until the mortar-slump is less than 50 % of the initial
mortar-slump.
9. Test Methods
9.1 Mortar-slump and Mortar-spread:
9.1.1 Dampen the mortar-slump mold and base plate by wiping with a moist towel. Place the mold on the base plate. Place the
plastic ring over the slump mold. Fill the mold with mortar using two layers of equal volume. Tamp each layer 15 times with the
tamping rod. Screed off excess mortar from the top of the mold with the trowel. Remove any excess mortar that may have fallen
on the base plate. Lift the mold up from the base plate in one steady motion within 2 s to 3 s.
9.1.2 Measure the mortar-slump by turning the mold upside down and setting it next to the slumped mortar. Do not disturb the
mortar specimen during the measurement process. Place the tamping rod across the bottom of the inverted slump mold so that it
extends over the slumped mortar. Using the ruler, measure straight down from the bottom of the tamping rod to the top of the
original displaced center of the slumped mortar. Record the vertical slump of the mortar to the nearest 1 mm [ ⁄16 in.].
9.1.3 With the calipers, measure the diameter of the horizontal flow or spread of the mortar at two locations, 90° apart. Calculate
the average spread and record to the nearest 1 mm [0.05 in.].
NOTE 9—Mortar slump and mortar-spread are empirical indicators of ease of mortar flow. The workability index, which is the sum of the two
measurements minus 100 for measurements in SI units or minus 5 for inch-pound units, may be used as an optional single indicator of mortar workability.
9.1.4 If mortar slump retention time is desired, continue mixing and testing the mortar in accordance with 8.13.
9.2 Air Content of Mortar Mixture:
9.2.1 Measure and record the mass of the empty 400 mL brass cup, or similar size container of known volume, to the nearest 0.5
g.
9.2.2 Using a spoon or scoop, place the mortar into the 400 mL brass cup, or similar size container with a known volume, in three
equal layers. Tamp each layer 20 times with the tamper around the inner surface of the cup. The long face of the tamper should
always coincide with the radius of the cup. Complete tamping each layer in one revolution of the cup. Use only sufficient pressure
to fill the measure and eliminate voids.
9.2.3 After the cup is filled, lightly tap the sides of the cup with the side of the tamping rod at five different points spaced equally
around the outside of the cup. Screed the mortar to a flat surface, flush with the top of the cup, using a trowel in a sawing motion.
Make two passes completely across the cup in two directions at right angles to each other. Complete the filling and strike-off
procedures within 90 s. Wipe off excess mortar from the sides and the top rim of the cup.
9.2.4 Measure and record the mass of the filled cup to the nearest 0.5 g.
9.2.5 Calculate the Density—Determine the density of the mortar (D) as follows:
D 5 M 2 C ⁄V (1)
~ !
c
where:
D = density, g/mL,
M = mass of mortar and cup, g
C = mass of empty cup, g, and
V = measured volume of cup, mL.
c
9.2.6 Calculate the Total Mass Batched—Determine the total mass of materials used to batch the mortar (W1) as follows:
W15 C1P1S1W (2)
C1810/C1810M − 23
where:
W1 = total mass of materials batched, g,
C = cement, g,
P = supplementary cementitious material (SCM), g,
S = sand at SSD condition, g, and
W = water, g, which includes the added mix water, water from the chemical admixtures, and moisture from the sand in excess
of the moisture content for the SSD condition of the sand. If the sand has less water than required for the SSD condition,
adjust the value of W by subtracting the water required to bring the sand to the SSD condition.
9.2.7 Calculate the Volume of Mortar Batched—Determine the volume of mortar (Y) as follows:
Y 5 W1⁄D (3)
where:
Y = volume of mortar in the batch, mL,
W1 = total mass of materials batched, g, and
D = density of mortar, g/mL.
9.2.8 Calculate the Absolute Volume of Materials Batched—Determine the absolute volume (V) of the materials in the mortar
batch as follows:
V 5 C ⁄ c 1 P ⁄ p 1 S ⁄ s 1W (4)
~ ! ~ ! ~ !
where:
V = absolute volume of all materials batched, mL,
C = mass of cement, g,
c = relative density (specific gravity) of cement,
P = mass of SCM, g,
p = relative density (specific gravity) of SCM,
S = mass of sand in SSD condition, g,
s = relative density (specific gravity) of sand in SSD condition, and
W = mass of water, g.
NOTE 10—All the terms on the right side of Eq 4 are actually divided by the density of water, which is assumed to equal 1 g/mL. For simplicity, this
factor has been omitted from the equation.
9.2.9 Calculate the Air Content, %, of the Mortar—Determine the air content of the mortar (A) as follows:
A 5 @~Y 2 V!⁄Y# ×100% (5)
where:
A = air content, %,
Y = volume of mortar in the batch, mL, and
V = absolute volume of all materials batched, mL.
9.3 Time of Set
...