The dry consistency of RCC results in difficulty in
bonding fresh concrete to hardened concrete.
This bond can be improved between the lifts by
reducing the time of casting the lifts or by increasing
the paste content in the mixture.
Typically, bedding mixtures contain 360 to 460
kg/m3 of cement, 170 to 220 kg/m3 of fly ash, and
4.75-mm maximum size aggregate.