Table 3.

WQI test procedure

StepComments
Preparations5 kg of aggregates, all passing 19 mm sieve and comprising 2000 ± 5 g of the material retained on the 9.50 mm sieve, and 3000 ± 5 g of that retained on the 4.75 mm sieve, are completely washed and dried
One cycle of the testWettingAggregates are placed in a flat-bottomed square tray, mixed thoroughly, and covered with distilled water for 18 ± 1 h
After the completion of the wetting cycle, the water is decanted from materials and retained for the next cycle of wetting (if necessary, more distilled water is added to cover the aggregates thoroughly)
DryingMaterials are dried in an oven for 4 h ± 15 min and then allowed to cool for 1–1.5 h
RollingMaterials are remixed in the tray and subjected to 100 cycles of loading by a 6 kg steel roller
Boiling and agitatingAfter accomplishing 10 cycles of W–D, and rolling, the sample is boiled for 1 h ± 5 min, and then cooled to 40°C in less than 15 min. Subsequently, the whole sample is agitated in 3000 ± 200 g of water (50 times within 100 ± 20 s)
Reporting the resultsAggregates are sieved over 4.75 mm and 75 μm sieve. The proportion of aggregates retained on the 4.75 mm sieve is expressed as a percentage of 5000 g. One litre of the slurry passing the 75 μm sieve is used to determine cleanness value (CV)*
  • * The height in millimetres of the column of sediment (a mixture of the slurry sample and the stock calcium chloride solution) after 20 min is reported as the CV.