This document discusses concrete admixtures, including their definitions, types, standards, and specifications. It describes the main types of chemical admixtures like water-reducers and air-entrainers. It outlines standards from ASTM and AASHTO for admixtures and discusses how admixtures can affect concrete properties, dosage guidelines, and testing requirements. Calcium chloride is noted for accelerating set time but inducing corrosion, while flowable concrete admixtures are covered by ASTM C1017.

1. CON 122
Concrete Admixtures
Session 2
Standards and Specifications

2. Concrete Admixture Definition
“A material other than
water, aggregates, hydraulic cement, and fiber
reinforcement used as an ingredient of concrete
and mortar added to the batch before or during
its mixing.”

3. Types of Concrete Admixtures
 Chemical Admixtures
 Air-entraining Admixtures
 Calcium Chloride
 Admixtures for Flowing Concrete
 Specific Special Performance Admixtures

4. Liquid Admixture
Standards and Specifications
Description Standards / Specifications
Water-reducing and set-controlling • ASTM C494
admixtures • AASHTO M 194
• ASTM C 260
Air-entraining admixtures
• AASHTO M 154
• ASTM D 98
Calcium Chloride
• AASHTO M 144
Admixtures for Flowing Concrete • ASTM C 1017
Specific Performance Admixtures • ASTM C 494

5. Standard Specification for Chemical
Admixtures for Concrete
 Type A – Water-reducing admixtures
 Type B – Retarding admixtures
 Type C – Accelerating admixtures
 Type D – Water-reducing and retarding
admixtures
 Type E – Water-reducing and accelerating
admixtures
 Type F – Water-reducing, high range admixtures
 Type G – Water-reducing, high range, retarding
ASTM Designation: C 494/C 494M - 99ϵ1

6. Low water to cement ratio
concrete with low chloride
permeability—easily made with
high-range water reducers.

7. Chemical Admixtures Effect
Concrete Properties
 Workability
 Durability
 Economics
 Increase/decrease set time
 Accelerate strength gain
 Control Temperature Gain
 Special Attributes

8. Chemical Admixtures Dosage
 Types A, B, and D (2 to 7 oz/100 lbs cementitious
material)
 Normal dosage: 5-8% water reduction; Type B and D
retard set
 Types C and E
 Normal dosage will accelerate set
 Types F and G (High-range superplastizers)
 High dosage at 10-90 oz/100 lbs cementitious material: 12-
25% water reduction
 Retards set

9. ASTM C 494 Physical Testing Requirements
ASTM Designation: C 494/C 494M - 99ϵ1

10. ASTM C 260 Air-Entraining
Admixtures
 1. Scope*
 1.1 This specification covers materials proposed for
use as air-entraining admixtures to be added to
concrete mixtures in the field.
 3.1.1. air-entraining admixture, n – for the
purpose of this specification, a material that is
used as an ingredient of concrete, added to the
batch immediately before or during its mixing, for
the purpose of entraining air.
ASTM Designation: C 260 - 01

11. Physical Requirements for Air-
Entraining Admixtures
ASTM Designation: C 260 - 01

12. Effects of Using Air-Entraining
Admixture
 Lubrication Effect of air bubbles
 Reduction of mixing water for equal slump
 Improved workability
 Causes sticky finishability

13. Concrete Producer Adjustments
 Aggregate Characteristics
 Proportions of concrete constituents
 Type and duration of mixing
 Consistency
 Temperature
 Cementitious Materials

14. Use of Calcium Chloride
 Accelerate Set Time
 Induces Corrosion of Metals
 Aggravate effects of poor quality construction

15. Use of Calcium Chloride

16. Consequences of Corrosion in
Concrete
Cracking Spalling

17. Corrosion of embedded steel
reinforcement is the #1 cause of
premature deterioration of
concrete infrastructure in North
America (and many other regions
worldwide).
17

18. Calcium Chloride D 98
Requirements

19. ASTM C 1017 Flowing Concrete
Mixtures
 1. Scope
 1.1 This specification covers two types of chemical
admixtures to be added to hydraulic cement
concrete mixtures for the purpose of producing
flowing concrete. The types are as follows:
 1.1.1. Type I – Plasticizing
 1.1.2. Type II – Plasticizing and retarding
ASTM Designation: C 1017/ C 1017M

20. ASTM C 1017 Flowing Concrete
Admixtures
ASTM Designation: C 1017/ C 1017M

21. New Specific Performance
Admixture, Type S
 Type S, has been added to C 494/ C 494M
 For admixtures that provide primary specific
performance benefits to concrete
 Other than water reduction, strength, or
modification of time of set.

22. Special Specific Performance
Admixtures, Type S