2.2.2. Washing
The coarse aggregate sourced from quarry usually contains a
high amount of adhere clay and other impurities. Before the mixing,
washing is a necessary procedure, the aggregate surface coatings
interfere with the development of bond between aggregate
and cement paste, which plays an important role in providing satisfactory
strength of porous concrete. Hence, the coarse aggregates
were washed using tap water and dried in oven for one day to remove
the silt or crusher dust.