Understanding Natural Sand Varieties in Central Ethiopia
Not all sand is created equal. Fine red sand from nearby pits may look convenient, but high clay and organic silt content severely degrades cement hydration, leading to surface dusting and weak plaster bonding.
Coarse river sand extracted from the Awash basin features clean sub-angular silica grains. A quick field bottle silt-settling test should yield less than 4% sediment height after 3 hours.
