Bulking of sand means increase in it’s volume due to presence of surface moisture.
Importance of Bulking of Sand
- The volume increases with increase in moisture content . The volume may increase up to 20 to 40% when moisture content is 5 to 10 %.
- As fine grained sands have higher voids than medium and coarse grained sands, the percentage of moisture absorbed and the percentage volume increase is the highest.
- When water is added to sand, a thin film of water is formed around the sand particles. The film exerts surface tension on particles, making them move apart. This leads to increase in volume because there is no direct contact among particles.