This standard specifies the methods for testing chemical admixtures to assess their effect on concrete properties. It details procedures for evaluating workability, water reduction, stiffening time, air entrainment in fresh concrete, and compressive strength of hardened concrete, alongside uniformity tests for the admixture itself.
Prescribes methods for testing the performance and compliance of chemical admixtures for concrete.
Quick Reference Values
Standard laboratory temperature for tests27 ± 2 °C
Standard laboratory relative humidity for tests65 ± 5 %
Penetration resistance for initial set time0.5 N/mm² (MPa)
Penetration resistance for final set time3.5 N/mm² (MPa)
Standard size of cube for compressive strength150 mm
Minimum concrete mixing time after adding water2 minutes
Key Formulas
Water Reduction % = [(Wc - Wt) / Wc] x 100 — Where Wc is water in control mix, Wt is water in test mix.
Air Content % (Pressure Method) = A1 - G — Where A1 is apparent air content and G is aggregate correction factor.
Compressive Strength (MPa) = P / A — Where P is the maximum load in Newtons and A is the cross-sectional area in mm².
Practical Notes
Crucially, this standard has been superseded and replaced by IS 9103:2023, which combines both specifications and test methods into a single document.
This code provides the 'how-to' for testing, while the pass/fail acceptance criteria were listed in the now-superseded IS 9103:1999. The two were designed to be used together.
When performing comparative tests, it is essential that the control concrete mix and the test concrete mix are identical in every respect (materials, proportions, temperature) except for the admixture being tested.