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
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
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
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.