ASTM C688-22

Standard Specification for Functional Additions for Use in Hydraulic Cements

ABSTRACT
This specification covers methods to investigate the effectiveness of a material to beneficially change the properties of hydraulic cements when the material is interground with the clinker during manufacture of the cement. Cement, mortar, and concrete shall be tested and the individual grades shall conform to specified values of autoclave expansion, drying shrinkage, normal consistency, standard consistency, setting time, compressive strength, false set, water content, flexural strength, bond to steel, volume change, resistance to freezing and thawing, and bleeding. Accelerating addition, retarding addition, set-control addition, water-reducing addition, water-reducing and accelerating addition are detailed.
SCOPE
1.1 This specification covers methods to investigate the effectiveness of a material to beneficially change the properties of hydraulic cements when the material is incorporated during manufacture of the cement.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 The effect of additions in cement may markedly change properties other than those they are intended to modify. This specification is designed to test for such changes. Table 1 sets forth values for those properties of cement pastes and mortars that would permit a judgment of the changes effected by an addition. Likewise, Table 2 sets forth similar criteria for concrete. Certain additions may be found effective for more than one purpose as indicated in 3.1.4 and 3.1.5.    
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.

General Information

• Status: Published
• Publication Date: 14-Dec-2022
• ICS: 91.100.10 - Cement. Gypsum. Lime. Mortar
• Technical Committee: C01 - Cement
• Drafting Committee: C01.20 - Additions

Relations

• Refers: ASTM C219-24 - Standard Terminology Relating to Hydraulic and Other Inorganic Cements
• Effective Date: 01-Apr-2024
• Refers: ASTM C10/C10M-24 - Standard Specification for Natural Cement
• Effective Date: 01-Jan-2024
• Refers: ASTM C109/C109M-23 - Standard Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 50 mm [2 in.] Cube Specimens)
• Effective Date: 15-Dec-2023
• Refers: ASTM C596-23 - Standard Test Method for Drying Shrinkage of Mortar Containing Hydraulic Cement
• Effective Date: 01-Dec-2023
• Refers: ASTM C39/C39M-23 - Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens
• Effective Date: 01-Dec-2023
• Refers: ASTM C219-20a - Standard Terminology Relating to Hydraulic and Other Inorganic Cements
• Effective Date: 01-Aug-2020
• Refers: ASTM C219-20 - Standard Terminology Relating to Hydraulic and Other Inorganic Cements
• Effective Date: 01-Apr-2020
• Refers: ASTM C219-19a - Standard Terminology Relating to Hydraulic and Other Inorganic Cements
• Effective Date: 15-Nov-2019
• Refers: ASTM C10/C10M-19 - Standard Specification for Natural Cement
• Effective Date: 01-Nov-2019
• Refers: ASTM C219-19 - Standard Terminology Relating to Hydraulic Cement
• Effective Date: 01-Jun-2019
• Refers: ASTM C596-18 - Standard Test Method for Drying Shrinkage of Mortar Containing Hydraulic Cement
• Effective Date: 01-Dec-2018
• Refers: ASTM C451-18 - Standard Test Method for Early Stiffening of Hydraulic Cement (Paste Method)
• Effective Date: 01-Oct-2018
• Refers: ASTM C465-18 - Standard Specification for Processing Additions for Use in the Manufacture<brk/> of Hydraulic Cements
• Effective Date: 01-Apr-2018
• Refers: ASTM C157/C157M-17 - Standard Test Method for Length Change of Hardened Hydraulic-Cement Mortar and Concrete
• Effective Date: 15-Aug-2017
• Refers: ASTM C39/C39M-17b - Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens
• Effective Date: 01-Aug-2017

Overview

ASTM C688-22, published by ASTM International, is the Standard Specification for Functional Additions for Use in Hydraulic Cements. This international standard establishes test methods and requirements to evaluate materials-referred to as functional additions-that are incorporated into hydraulic cements during manufacture to beneficially change properties such as setting time, workability, and strength. The specification outlines how these additions should be tested in cement, mortar, and concrete, ensuring that their incorporation meets rigorous performance criteria. By following ASTM C688-22, manufacturers and stakeholders in the construction industry can assure the quality, safety, and performance of hydraulic cement products that include these functional additives.

Key Topics

• Types of Functional Additions: The standard specifies and defines several categories of functional additions, including:

  • Accelerating additions: Enhance early setting or strength development
  • Retarding additions: Delay setting to improve workability time
  • Set-control additions: Composed mainly of calcium sulfate to control set times
  • Water-reducing additions: Lower the water required for a given consistency, enhancing strength or reducing permeability
  • Water-reducing and accelerating additions: Combine water reduction with accelerated setting or strength
  • Water-reducing and retarding additions: Lower water content and extend workability

• Performance Evaluation: The standard covers testing for properties such as:

  • Setting time (initial and final)
  • Compressive strength at various ages
  • Flexural strength
  • Bond strength to steel
  • Autoclave expansion and drying shrinkage
  • Volume changes, resistance to freezing and thawing, and bleeding

• Testing Methods: Utilizes established ASTM test methods such as:

  • ASTM C143 for slump
  • ASTM C39/C109 for compressive strength
  • ASTM C78 for flexural strength
  • ASTM C151, C266, C232, and others

• Conformance Requirements: All grades and batches must meet minimum performance values as detailed in standard tables to ensure expected behavior in both mortar and concrete.

Applications

• Cement Manufacturing: Used by cement manufacturers to select and validate additives that improve product performance. Functional additions can target specific goals, such as speeding up or slowing down setting, or enhancing concrete durability under challenging conditions.

• Concrete Mixture Design: Specification is vital for designing concrete mixes where consistency, set time, strength, or workability must meet project requirements, especially in large infrastructure or time-sensitive projects.

• Quality Assurance: Applied in quality control laboratories to routinely evaluate new or modified materials. Ensures compliance with regulatory requirements and enhances confidence among end-users.

• Research and Material Development: Guides research into novel admixtures and materials intended to modify hydraulic cement performance for sustainability, efficiency, or advanced construction techniques.

Related Standards

ASTM C688-22 makes reference to and is used in conjunction with other key standards in the field of hydraulic cement and concrete, including:

• ASTM C10/C10M - Specification for Natural Cement
• ASTM C39/C39M - Test Methods for Compressive Strength of Cylindrical Concrete Specimens
• ASTM C78 - Test Method for Flexural Strength of Concrete
• ASTM C109/C109M - Test Method for Compressive Strength of Hydraulic Cement Mortars
• ASTM C143/C143M - Slump of Hydraulic-Cement Concrete
• ASTM C150 - Specification for Portland Cement
• ASTM C266 - Time of Setting of Hydraulic-Cement Paste by Gillmore Needles
• ASTM C465 - Specification for Processing Additions for Use in the Manufacture of Hydraulic Cements
• ASTM C595 - Specification for Blended Hydraulic Cements

Keywords: hydraulic cement, functional addition, ASTM C688-22, cement additive, set-control, water-reducing, accelerating addition, retarding addition, cement testing, concrete performance, standard specification

Standards Content (Sample)

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.
Designation:C688 −22
Standard Specification for
Functional Additions for Use in Hydraulic Cements
This standard is issued under the fixed designation C688; 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* C143/C143M Test Method for Slump of Hydraulic-Cement
Concrete
1.1 This specification covers methods to investigate the
C150 Specification for Portland Cement
effectiveness of a material to beneficially change the properties
C151 Test Method for Autoclave Expansion of Hydraulic
of hydraulic cements when the material is incorporated during
Cement
manufacture of the cement.
C157/C157M Test Method for Length Change of Hardened
1.2 The values stated in SI units are to be regarded as
Hydraulic-Cement Mortar and Concrete
standard. No other units of measurement are included in this
C187 Test Method for Amount of Water Required for Nor-
standard.
mal Consistency of Hydraulic Cement Paste
C219 Terminology Relating to Hydraulic and Other Inor-
1.3 The effect of additions in cement may markedly change
properties other than those they are intended to modify. This ganic Cements
C226 Specification for Air-Entraining Additions for Use in
specification is designed to test for such changes. Table 1 sets
forth values for those properties of cement pastes and mortars the Manufacture of Air-Entraining Hydraulic Cement
C232 Test Method for Bleeding of Concrete
that would permit a judgment of the changes effected by an
addition. Likewise, Table 2 sets forth similar criteria for C234 Test Method for Comparing Concretes on the Basis of
the Bond Developed with Reinforcing Steel (Withdrawn
concrete. Certain additions may be found effective for more
than one purpose as indicated in 3.1.4 and 3.1.5. 2000)
C266 Test Method for Time of Setting of Hydraulic-Cement
1.4 This international standard was developed in accor-
Paste by Gillmore Needles
dance with internationally recognized principles on standard-
C403/C403M Test Method for Time of Setting of Concrete
ization established in the Decision on Principles for the
Mixtures by Penetration Resistance
Development of International Standards, Guides and Recom-
C451 Test Method for Early Stiffening of Hydraulic Cement
mendations issued by the World Trade Organization Technical
(Paste Method)
Barriers to Trade (TBT) Committee.
C465 Specification for Processing Additions for Use in the
Manufacture of Hydraulic Cements
2. Referenced Documents
C595 Specification for Blended Hydraulic Cements
2.1 ASTM Standards:
C596 Test Method for Drying Shrinkage of Mortar Contain-
C10/C10M Specification for Natural Cement
ing Hydraulic Cement
C39/C39M Test Method for Compressive Strength of Cylin-
C666/C666M Test Method for Resistance of Concrete to
drical Concrete Specimens
Rapid Freezing and Thawing
C78 Test Method for Flexural Strength of Concrete (Using
C845 Specification for Expansive Hydraulic Cement
Simple Beam with Third-Point Loading)
C1157 Performance Specification for Hydraulic Cement
C109/C109M Test Method for Compressive Strength of
Hydraulic Cement Mortars (Using 2-in. or [50 mm] Cube
3. Terminology
Specimens)
3.1 Definitions:
3.1.1 accelerating addition—a functional addition that ac-
celerates the setting or early strength, or both, of concrete and
This specification is under the jurisdiction of ASTM Committee C01 on
mortar.
Cement and is the direct responsibility of Subcommittee C01.20 on Additions.
3.1.2 retarding addition—a functional addition that retards
Current edition approved Dec. 15, 2022. Published January 2023. Originally
approved in 1971. Last previous edition approved in 2014 as C688 – 14. DOI:
the setting of concrete and mortar.
10.1520/C0688-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
*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
C688−22
TABLE 1 Criteria for Evaluating Neat Cement and Mortar Containing Functional Cement Additions
Type of Addition
Tests
Water-Reducing Water-Reducing and
Water Reducing Retarding Accelerating Set-Control
and Retarding Accelerating
Normal consistency, deviation from control, −1.0 min +1.0 max +1.0 max −1.0 min −1.0 mm ±1.0 max
A
percentage points
Standard consistency (flow) deviation from −4.0 min +2.0 max +2.0 max −4.0 min −4.0 min ±2.0 max
A
control, percentage points
Setting time, (Gillmore) deviation from control,
h:min
Initial
B B
At least . 1:00 later 1:00 later .
Not more than 1:00 earlier 3:30 later 1:30 earlier 3:30 later 1:30 earlier 1:00 earlier
nor nor nor nor
1:30 later 1:30 later 1:30 later 1:30 later
C
Setting time, Vicat Initial
B
At least . 0:50 later . . .
B
Not more than 0:50 earlier 2:50 later 1:15 earlier 0:50 later 1:15 earlier 0:50 earlier
nor nor nor nor
1:15 later 1:15 later 2:50 later 1:15 later 1:15 later
Final
Not more than 1:00 earlier 3:30 later 1:00 earlier 3:30 later 1:00 earlier 1:00 earlier
nor nor nor nor
1:30 later 1:30 later 1:30 later 1:30 later
D
Compressive strength, min, percent of control:
E F
1 day in moist air 110 90 125 90 125
E
1 day in moist air, 2 days in water 110 90 125 100 125
1 day in moist air, 6 days in water 110 90 100 110 110
1 day in moist air, 27 days in water 110 95 95 110 110
Autoclave Expansion
max increase in % change in length compared 0.10 0.10 0.10 0.10 0.10 0.10
to control
Drying Shrinkage of Mortar
max % change in length compared to control 0.020 0.020 0.030 0.020 0.020 0.020
A
The minus sign indicates that the percentage of water required shall be less than that of the control cement by at least the indicated percentage points.
B
Or 50 % later, whichever is the lesser.
C
Either Vicat or the Gillmore time of setting method shall be used at the choice of the manufacturer.
D
The compressive strength of mortar containing the test cement shall be not less than 95 % of that attained at any previous test age. The objective of this limit is to require
that the strength of mortar containing the addition under test shall not decrease with age.
E
In cases where the accelerated set time only is required, the strength can be reduced to 100 % of the control.
F
The grand average of the 1, 3, 7, and 28-day strengths shall be not less than 95 % of the grand average for the corresponding control cement.
3.1.3 set-control addition—a functional addition composed 5. Materials
essentially of calcium sulfate in any hydration state from
5.1 Cements—The cements used in the evaluation of the
CaSO to CaSO ·2H O.
4 4 2
addition shall be as described in Section 3.1, Cements, of
3.1.4 water-reducing addition—a functional addition used
Specification C465 with the following exceptions:
to reduce the quantity of mixing water required to produce
5.1.1 At least one of the Type I cements shall contain not
concrete and mortar of a given consistency.
less than 9 percent tricalcium aluminate (C A).
3.1.5 water-reducing and accelerating addition—a func-
5.1.2 Disregard the last sentence of Section 3.1.6 of Speci-
tional addition that reduces the quantity of mixing water
fication C465 and substitute the following: “ Each control
required to produce concrete of a given consistency and that
cement shall comply with all the requirements in the specifi-
accelerates the setting or early strength development, or both,
cation (C10/C10M, C150, C595, C845, and C1157) applicable
of concrete and mortar.
to that type of cement. The method shall be adequate for the
qualitative and quantitative determination of the addition in the
3.1.6 water-reducing and retarding addition—a functional
finishedcement,andshallbefullydescribedinthereportofthe
addition that reduces the quantity of mixing water required to
tests on the addition.”
produce concrete and mortar of a given consistency and
simultaneously retards the setting of concrete and mortar.
5.2 Aggregates—The aggregates used in the evaluation of
the addition shall be in accordance with theAggregates portion
NOTE 1—This section is intended to provide a specification that may be
applied to calcium sulfates as defined in Terminology C219.
of the Materials section of Specification C465, using propor-
NOTE 2—It should be realized that some calcium sulfates, particularly
tions specified in Concrete Mixtures section of that specifica-
some byproduct calcium sulfates, have produced cements with undesired
tion.
set behavior after storage.
6. General Requirements
4. Ordering Information
4.1 The purchaser shall specify the type of functional 6.1 The cement, mortar, and concrete in which each of the
addition desired. additions is used shall conform to the respective requirements
C688−22
A
TABLE 2 Criteria for Evaluating Concrete Containing Functional Cement Additions
Type of Addition
Tests
Water-Reducing Water-Reducing
Water Reducing Retarding Accelerating
and Retarding and Accelerating
Water content, max, percent of control 95 . . 95 95
Time of setting, (penetration) deviation from
control, h:min:
Initial
B B
At least . 1:00 later 1:00 later
Not more than 1:00 earlier 3:30 later 3:30 earlier 3:30 later 3:30 earlier
nor
Final 1:00 later
Not more than 1:00 earlier 3:30 later . 3:30 later .
nor
1:30 later
Compressive strength, min, percent of
C
control:
D E
1 day 110 85 125 100 125
E
3 days 110 85 125 100 125
7 days 110 90 100 110 110
28 days 110 90 95 110 110
3 months 100 90 95 100 100
1 year 100 90 95 100 100
Flexural strength, min, percent of
C
control:
D
1 day 100 85 110 90 110
3 days 100 85 110 100 110
7 days 100 90 100 100 100
28 days 100 90 90 100 100
3 months 100 90 90 100 100
1 year 100 90 90 100 100
Bond strength, percent of control:
28 days 100 90 100 100 100
Volume change, expressed as change in
length, max, increase over control,
percentage points:
28 days 0.010 0.010 0.030 0.010 0.010
3 months 0.010 0.010 0.030 0.010 0.010
1 year 0.010 0.010 0.030 0.010 0.010
F
Durability factor, min, percent of control 80 80 80 80 80
A
The values in the table are intended to allow for normal variation in test results. For example, the object of the 90 % compressive strength requirement for a retarding
addition is to require a level of performance comparable to that of the reference
...

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: C688 − 14 C688 − 22
Standard Specification for
Functional Additions for Use in Hydraulic Cements
This standard is issued under the fixed designation C688; 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 specification covers methods to investigate the effectiveness of a material to beneficially change the properties of
hydraulic cements when the material is incorporated during manufacture of the cement.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 The effect of additions in cement may markedly change properties other than those they are intended to modify. This
specification is designed to test for such changes. Table 1 sets forth values for those properties of cement pastes and mortars that
would permit a judgment of the changes effected by an addition. Likewise, Table 2 sets forth similar criteria for concrete. Certain
additions may be found effective for more than one purpose as indicated in 3.1.4 and 3.1.5.
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:
C10/C10M Specification for Natural Cement
C39/C39M Test Method for Compressive Strength of Cylindrical Concrete Specimens
C78 Test Method for Flexural Strength of Concrete (Using Simple Beam with Third-Point Loading)
C109/C109M Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 2-in. or [50 mm] Cube Specimens)
C143/C143M Test Method for Slump of Hydraulic-Cement Concrete
C150 Specification for Portland Cement
C151 Test Method for Autoclave Expansion of Hydraulic Cement
C157/C157M Test Method for Length Change of Hardened Hydraulic-Cement Mortar and Concrete
C187 Test Method for Amount of Water Required for Normal Consistency of Hydraulic Cement Paste
C219 Terminology Relating to Hydraulic and Other Inorganic Cements
C226 Specification for Air-Entraining Additions for Use in the Manufacture of Air-Entraining Hydraulic Cement
C232 Test Method for Bleeding of Concrete
C234 Test Method for Comparing Concretes on the Basis of the Bond Developed with Reinforcing Steel (Withdrawn 2000)
C266 Test Method for Time of Setting of Hydraulic-Cement Paste by Gillmore Needles
C403/C403M Test Method for Time of Setting of Concrete Mixtures by Penetration Resistance
This specification is under the jurisdiction of ASTM Committee C01 on Cement and is the direct responsibility of Subcommittee C01.20 on Additions.
Current edition approved Feb. 1, 2014Dec. 15, 2022. Published March 2014January 2023. Originally approved in 1971. Last previous edition approved in 20082014 as
C688 – 08.C688 – 14. DOI: 10.1520/C0688-14. 10.1520/C0688-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
*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
C688 − 22
TABLE 1 Criteria for Evaluating Neat Cement and Mortar Containing Functional Cement Additions
Type of Addition
Tests
Water-Reducing Water-Reducing and
Water Reducing Retarding Accelerating Set-Control
and Retarding Accelerating
Normal consistency, deviation from control, −1.0 min +1.0 max +1.0 max −1.0 min −1.0 mm ±1.0 max
A
percentage points
Standard consistency (flow) deviation from −4.0 min +2.0 max +2.0 max −4.0 min −4.0 min ±2.0 max
A
control, percentage points
Setting time, (Gillmore) deviation from control,
h:min
Initial
B B
At least . 1:00 later 1:00 later .
Not more than 1:00 earlier 3:30 later 1:30 earlier 3:30 later 1:30 earlier 1:00 earlier
nor nor nor nor
1:30 later 1:30 later 1:30 later 1:30 later
C
Setting time, Vicat Initial
B
At least . 0:50 later . . .
B
Not more than 0:50 earlier 2:50 later 1:15 earlier 0:50 later 1:15 earlier 0:50 earlier
nor nor nor nor
1:15 later 1:15 later 2:50 later 1:15 later 1:15 later
Final
Not more than 1:00 earlier 3:30 later 1:00 earlier 3:30 later 1:00 earlier 1:00 earlier
nor nor nor nor
1:30 later 1:30 later 1:30 later 1:30 later
D
Compressive strength, min, percent of control:
E F
1 day in moist air 110 90 125 90 125
E
1 day in moist air, 2 days in water 110 90 125 100 125
1 day in moist air, 6 days in water 110 90 100 110 110
1 day in moist air, 27 days in water 110 95 95 110 110
Autoclave Expansion
max increase in % change in length compared 0.10 0.10 0.10 0.10 0.10 0.10
to control
Drying Shrinkage of Mortar
max % change in length compared to control 0.020 0.020 0.030 0.020 0.020 0.020
A
The minus sign indicates that the percentage of water required shall be less than that of the control cement by at least the indicated percentage points.
B
Or 50 % later, whichever is the lesser.
C
Either Vicat or the Gillmore time of setting method shall be used at the choice of the manufacturer.
D
The compressive strength of mortar containing the test cement shall be not less than 95 % of that attained at any previous test age. The objective of this limit is to require
that the strength of mortar containing the addition under test shall not decrease with age.
E
In cases where the accelerated set time only is required, the strength can be reduced to 100 % of the control.
F
The grand average of the 1, 3, 7, and 28-day strengths shall be not less than 95 % of the grand average for the corresponding control cement.
C451 Test Method for Early Stiffening of Hydraulic Cement (Paste Method)
C465 Specification for Processing Additions for Use in the Manufacture of Hydraulic Cements
C595 Specification for Blended Hydraulic Cements
C596 Test Method for Drying Shrinkage of Mortar Containing Hydraulic Cement
C666/C666M Test Method for Resistance of Concrete to Rapid Freezing and Thawing
C845 Specification for Expansive Hydraulic Cement
C1157 Performance Specification for Hydraulic Cement
3. Terminology
3.1 Definitions:
3.1.1 accelerating addition—a functional addition that accelerates the setting or early strength, or both, of concrete and mortar.
3.1.2 retarding addition—a functional addition that retards the setting of concrete and mortar.
3.1.3 set-control addition—a functional addition composed essentially of calcium sulfate in any hydration state from CaSO to
CaSO ·2H O.
4 2
3.1.4 water-reducing addition—a functional addition used to reduce the quantity of mixing water required to produce concrete and
mortar of a given consistency.
3.1.5 water-reducing and accelerating addition—a functional addition that reduces the quantity of mixing water required to
produce concrete of a given consistency and that accelerates the setting or early strength development, or both, of concrete and
mortar.
C688 − 22
A
TABLE 2 Criteria for Evaluating Concrete Containing Functional Cement Additions
Type of Addition
Tests
Water-Reducing Water-Reducing
Water Reducing Retarding Accelerating
and Retarding and Accelerating
Water content, max, percent of control 95 . . 95 95
Time of setting, (penetration) deviation from
control, h:min:
Initial
B B
At least . 1:00 later 1:00 later
Not more than 1:00 earlier 3:30 later 3:30 earlier 3:30 later 3:30 earlier
nor
Final 1:00 later
Not more than 1:00 earlier 3:30 later . 3:30 later .
nor
1:30 later
Compressive strength, min, percent of
C
control:
D E
1 day 110 85 125 100 125
E
3 days 110 85 125 100 125
7 days 110 90 100 110 110
28 days 110 90 95 110 110
3 months 100 90 95 100 100
1 year 100 90 95 100 100
Flexural strength, min, percent of
C
control:
D
1 day 100 85 110 90 110
3 days 100 85 110 100 110
7 days 100 90 100 100 100
28 days 100 90 90 100 100
3 months 100 90 90 100 100
1 year 100 90 90 100 100
Bond strength, percent of control:
28 days 100 90 100 100 100
Volume change, expressed as change in
length, max, increase over control,
percentage points:
28 days 0.010 0.010 0.030 0.010 0.010
3 months 0.010 0.010 0.030 0.010 0.010
1 year 0.010 0.010 0.030 0.010 0.010
F
Durability factor, min, percent of control 80 80 80 80 80
A
The values in the table are intended to allow for normal variation in test results. For example, the object of the 90 % compressive strength requirement for a retarding
addition is to require a level of performance comparable to that of the reference concrete.
B
Or 50 % later, whichever is the lesser.
C
The compressive and flexural strength of the concrete containing the addition under test at any test age shall be not less than 90 % of that attained at any previous test
age. The objective of this limit is to require that the compressive or flexural strength of the concrete containing the addition under test shall not decrease with age.
D
One-day strengths applicable only to Type III cement. One-year strength tests shall be made; however, the addition may be approved after completion of the 3-month
strength results, at the discretion of the purchaser.
E
In cases where the accelerated set time only is required, the strength can be reduced to 100 % of the control.
F
This requirement is applicable only when the addition is to be used in air-entrained concrete.
3.1.6 water-reducing and retarding addition—a functional addition that reduces the quantity of mixing water required to produce
concrete and mortar of a given consistency and simultaneously retards the setting of concrete and mortar.
NOTE 1—This section is intended to provide a specification that may be applied to calcium sulfates as defined in Terminology C219.
NOTE 2—It should be realized that some calcium sulfates, particularly some byproduct calcium sulfates, have produced cements with undesired set
behavior after storage.
4. Ordering Information
4.1 The purchaser shall specify the type of functional addition desired.
5. Materials
5.1 Cements—The cements used in the evaluation of the addition shall be as described in Section 3.1, Cements, of Specification
C465 with the following exceptions:
5.1.1 At least one of the Type I cements shall contain not less than 9 percent tricalcium aluminate (C A).
...