IS 1199 Part 8

: 2018

Methods of sampling and analysis of concrete - Part 8: Determination of compacting factor

CurrentEssentialTesting MethodMaterials Science · Testing Methods and Quality Control
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This code specifies the procedure for determining the workability of fresh concrete using the compacting factor test. Engineers and QA/QC personnel use this standard primarily for low workability concrete mixes where the standard slump test is not sensitive enough to yield reliable measurements.

Describes the method for determining the compacting factor of fresh concrete, an indicator of its workability.

Quick Reference Values
Top diameter of slump cone100 ± 2 mm
Bottom diameter of slump cone200 ± 2 mm
Height of slump cone300 ± 2 mm
Tamping rod diameter16 ± 1 mm
Tamping rod length600 ± 5 mm
Number of layers for filling3 equal layers (by volume)
Tamping strokes per layer25 strokes
Time to lift the mould5 to 10 seconds
Total time to complete testMax 150 seconds from start of filling
Key Formulas
Compacting Factor = (m1 - m) / (m2 - m) — where m1 is mass of partially compacted concrete with cylinder, m2 is mass of fully compacted concrete with cylinder, m is mass of empty cylinder
Practical Notes
The slump measurement is taken from the highest point of the slumped concrete to the underside of the tamping rod placed over the mould.
If the concrete shears (one half slides down along an inclined plane) or collapses completely laterally, the test is invalid and must be repeated from the same batch.
The base plate must be placed on a level, rigid, and horizontal surface free from vibrations.