Truck Mixtures. Each truck mixers shall be equipped with accurate water metre located between the supply tank and mixture and having a dial or digital indicator and a reliable revolution counter, located near the water metre, which can be readily reset to zero for indicating there total number of revolutions of the drum from each batch. Each mixer shall have affixed thereto a metal plate in which the drum operations in terms of volume for both mixing and agitating and the maximum and minimum speeds of rotations of the drum are plainly mixed. Mixing shall be continued for the minimum period specified, any may be increased and No. of revolutions, speed of the drum may be such that the mix as delivered from the mixer has uniform distribution of materials and the mass is uniform in colour and consistency to the satisfaction of Engineer-in-Charge. In no case, shall the design water content be exceeded. Concrete shall be discharged within half an hour after introducing of the mix water and cement into the mixer. Each batch of concrete, when delivered at the job site from commercial ready mix plants, shall be accompanied by a written certificate of batch weights and time of batching.
