This standard specifies the requirements and testing methods for chemical admixtures used in plain, reinforced, and prestressed concrete. It classifies admixtures like plasticizers, superplasticizers, retarders, and accelerators and defines their performance criteria related to workability, setting time, and strength.
Specified requirements for various types of chemical admixtures for concrete, including plasticizers, superplasticizers, retarders, and accelerators.
Quick Reference Values
Minimum water reduction for Normal Water-Reducing Admixtures5 percent
Minimum water reduction for Superplasticizers20 percent
Maximum chloride ion content for reinforced/prestressed concrete0.05 percent by mass of admixture
Initial setting time delay for Retarding AdmixturesMinimum 60 minutes
Maximum initial setting time delay for Retarding AdmixturesMaximum 360 minutes
Minimum 1-day compressive strength for Accelerating Admixtures125 percent of control
Minimum 7-day compressive strength for Superplasticizers140 percent of control
Practical Notes
Always conduct compatibility tests between the specific cement, aggregates, and admixture before mass use, as performance can vary significantly.
Strictly adhere to the manufacturer's recommended dosage. Overdosing can cause severe segregation and bleeding, while underdosing fails to achieve desired effects.
Pay close attention to the chloride content of the admixture (Table 2), especially for reinforced and prestressed concrete, to prevent long-term rebar corrosion.