When piles are driven through an upper layer of granular soils, thick (10mm) bitumen layer would be scrapped off during the driving process. A thin coat of 1mm to 2 mm thick is not likely to flow in storage and to peel off during pie driving.
The bitumen can be applied by brushing or sprinkling after heated to a liquid state. In cold weather conditions, it may be difficult to handle hot bitumen. As such, the bitumen could be mixed with solvent to soften the bitumen which should be able to cure rapidly to ensure that the bitumen coat stays on the piles.
For precast piles, a primer could be added to achieve better cohesion of bitumen to the piles.
This question is taken from book named – A Self Learning Manual – Mastering Different Fields of Civil Engineering Works (VC-Q-A-Method) by Vincent T. H. CHU.
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