As per ACI 212.3R-10, Concrete admixture is a material other than water, aggregates, hydraulic cement, and fiber reinforcement used as an ingredient of concrete or mortar, and added to the batch immediately before or during its mixing. Concrete admixtures are used to improve concrete or mortar properties in plastic and hardened state. In this article, we contrast the specifications for the testing methods, properties, and applications offered by various codes (ACI, ASTM and IS) for concrete admixture.
So, various types of concrete admixtures such as water-reducing admixtures, retarding admixtures, accelerating admixtures, water-reducing and retarding admixtures, water-reducing and accelerating admixtures, water-reducing high range admixtures, and water-reducing, high range, and retarding shall conform to the specification of the applicable codes otherwise the expected results would not be obtained.
Types of Admixtures and Their Standard Codes
Table 1 Types of Admixtures used in concrete and mortar, and Standard Codes Pertaining to each Admixture
| Types of Admixtures | Standard Codes | Notes |
| Water-reducing (WR) | ASTM C 494/C 494M – 99 | This specification covers materials for use as chemical admixtures to be added to hydraulic-cement concrete mixtures in the field. stipulates tests of an admixture with suitable concreting materials or with cement, pozzolana, aggregates, and an air-entraining admixture. |
| WR | ACI 212.3R-10 | It is a complete report about almost all types of admixtures used in concrete and mortar. It discusses the materials, selection, evaluation, applications, proportioning concrete, effects on hardening concrete, effects on fresh concrete, quality assurance, and storage of concrete admixtures. |
| WR | IS:9103 | This standard covers the chemical and air entraining admixtures including superplasticizers, solid or liquid or emulsion, to be added to cement concrete at the time of mixing so as to achieve the desired property in concrete, in the plastic or hardened state. |
| WR | AASHTO M154 | -- |
| Retarding (R) | ASTM C 494/C 494M – 99 | See the description in the first row of this table |
| R | ACI 212.3R-10 | Look at the explanation in the second row of this table |
| R | IS:9103 | Look at the explanation in the third row of this table |
| R | BS:5075 part 1 | -- |
| Accelerating (A) | ASTM C 494/C 494M – 99 | See the description in the first row of this table |
| A | ACI 212.3R-10 | Look at the explanation in the second row of this table |
| A | IS:9103 and IS:2645 | Look at the explanation in the third row of this table |
| Water-reducing and retarding | ASTM C 494/C 494M – 99 | See the description in the first row of this table |
| Water-reducing and accelerating | ASTM C 494/C 494M – 99 | See the description in the first row of this table |
| Water-reducing high range (WRHR) | ASTM C 494/C 494M – 99 | See the description in the first row of this table |
| WRHR | IS:9103 | Look at the explanation in the third row of this table |
| WRHR | BS 5075: Part 3: 1985 | -- |
| Water-reducing, high range, and retarding | ASTM C 494/C 494M – 99 | See the description in the first row of this table |
| Air entraining (AE) | ASTM C 260-00 | This specification covers materials proposed for use as air-entraining admixtures to be added to concrete mixtures in the field. It provides specifications regarding sampling, testing methods, and performance requirements. |
| ` AE | IS:9103 | Look at the explanation in the third row of this table |
| Integral waterproofing admixtures | IS:2645 | This type of admixture can be used with all types of concrete, mortars, masonry works, and guniting works, and shall conform to the specifications of IS:2645 |
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