This specification relates to systems (100), methods and apparatus for intelligently controlling the drum rotation of a concrete mixer (104). According to a first aspect of this specification, there is described a method for controlling a concrete mixing drum (104) on a concrete mixer vehicle (102), the method comprising, for each of a plurality of time-steps: inputting, into one or more machine-learned models (210), input data comprising a current state of the concrete mixer vehicle and one or more delivery requirements for a concrete mix in the concrete mixing drum; processing, using the one or more machine-learned models, the input data to generate a drum rotation cycle data (c) for the concrete mixing drum; outputting, from the one or more machine-learned models, the drum rotation cycle data; and controlling the concrete mixing drum based on the generated drum rotation cycle data.

A concrete mixer system includes a non-transitory computer-readable medium. The non-transitory computer-readable medium stores instructions causing one or more processor to perform operations. The operations include receiving an indication that a mixing drum of a concrete mixer vehicle is about to be charged and controlling an electronically controllable valve in response to the indication such that a fluid is provided to a nozzle to facilitate pre-wetting a charge hopper of the concrete mixer vehicle prior to the mixing drum being charged.

Compositions and methods are provided for a system in which liquid carbon dioxide, or a mixture of liquid and gaseous carbon dioxide, is converted to solid carbon dioxide by exiting an orifice at a sufficient pressure drop, e.g., for delivery of carbon dioxide to a concrete mixture in a mixer.

A concrete mixer vehicle includes a trainer cab that is coupled to a chassis and arranged laterally outwardly relative to a main cab. The trainer cab includes: (a) a seat mounted to a recessed mounting floor that is arranged rearward of a wheel well, (b) a support beam that includes an air vent and air flow path integrated into the support beam, or (c) a windshield wiper with a park location that is arranged between a trainer cab column and a superstructure support so that the windshield wiper is hidden from being viewed from within the main cab.