What will be differences on the fresh properties of concrete if it is mixed in the drum mixer for 30 seconds, 3 minutes and 25 minutes.
Effect of Mixing Time in drum research paper by TekRaj Gyanwali
Main Effects – Variation in Slump value, Compaction Factor, Compressive Strength
Slump Value
- For initial three minutes of mixing slump value is higher due to inadequate mixing time.
- From 4 to 7 minutes of mixing the slump value is better than that of other durations of mixing.
- From 8 to 10 minutes of mixing the slump value again increases due to segregation of concrete ingredients caused by prolonged mixing
Compressive strength
- For initial 2-3 minutes of mixing, results show low values of compressive strength is due to adequate mixing
- For mixing time within 4 to 7 minutes the compressive strength was maximum
- Further mixing may result in lower strength probably due to segregation of concrete ingredients.
Compaction Factor
- For initial two minutes of mixing results shows higher values compaction factor. But due inadequate mixing, the concrete cannot be properly compacted.
- For final 2 minutes also, the results are higher due to inadequate compaction but due to segregation of material