A vehicle includes an engine, an electric energy system, a drum configured to mix drum contents received therein, and a drum drive system coupled to the drum and the engine. The drum drive system includes a primary pump, an electric motor powered by the electric energy system, an auxiliary pump fluidly coupled to the mechanical pump and powered by the electric motor, and a drum motor fluidly coupled to the primary pump and the auxiliary pump and positioned to drive the drum to agitate the drum contents.

There is described a method for determining a volume of fresh concrete being discharged from a dmm during a discharge, the drum being rotatable and having inwardly protruding blades mounted inside the drum which, when the drum is rotated in an unloading direction, force the fresh concrete towards a discharge outlet of the drum. The method generally has discharging a volume of the fresh concrete from the drum by rotating the drum in the unloading direction for a given number of discharge rotations; obtaining discharge flow rate variation data indicative of a discharge flow rate varying as function of discharge rotations; and determining a discharged volume value indicative of the volume of fresh concrete being discharged from the drum of the mixer truck during said discharge based on the given number of discharge rotations and on the discharge flow rate variation data.

A mixing drum includes a body defining a head aperture and a discharge aperture opposite the head aperture, a head coupled to the body and extending across the head aperture, and a mixing element positioned within the volume and coupled to the body. The head and the body define a volume. The body is formed from at least a first section and a second section. The first section overlaps the second section.

There is described a system generally having a rotatable drum rotatably for receiving fresh concrete, the drum having inwardly protruding blades mounted inside the drum which, when the drum is rotated in an unloading direction, force fresh concrete inside the drum towards a discharge outlet of the drum, at least one discharge outlet sensor disposed at the discharge outlet of the drum and being configured to sense the presence of fresh concrete at the discharge outlet as the drum rotates in the unloading direction; and a controller communicatively coupled with the at least one discharge outlet sensor, the controller being configured for performing the steps of: receiving a signal from the at least one discharge outlet sensor indicative of the presence of the discharged fresh concrete at the discharge outlet as the drum rotates in the unloading direction; and determining at least one parameter based on the received signal.

A mixing drum includes a body defining a head aperture and a discharge aperture opposite the head aperture, a head coupled to the body and extending across the head aperture, a bearing member coupled to the body and defining a bearing surface surrounding the body, and a mixing element positioned within the volume and coupled to the body. The head and the body define a volume configured to contain a fluid mixture. The mixing element is configured to drive the fluid mixture toward the head when the drum is rotated in a first direction. The mixing element is configured to drive the fluid mixture towards the discharge aperture when the mixing drum is rotated in a second direction opposite the first direction. The head is made from a first material, and the body is made from a second material having a lesser density than the first material.

In accordance with one embodiment, a method is provided that includes providing a liquid nitrogen storage system configured to cool a supply of liquid nitrogen to a temperature below the vapor point of liquid nitrogen; coupling a piping system with the liquid nitrogen storage system to convey a portion of the supply of liquid nitrogen from the liquid nitrogen storage system; coupling the piping system with a liquid nitrogen control valve configured to control a flow of liquid nitrogen to at least one liquid nitrogen dispensing head; disposing the at least one liquid nitrogen dispensing head above a conveyance device operable to convey an aggregate stream of a concrete batching plant during use; and disposing the at least one liquid nitrogen dispensing head in a position to dispense an output flow of liquid nitrogen onto the aggregate stream of the concrete batching plant during use.

A concrete mixer vehicle includes a mixer drum, an additive admixture system, and a controller. The additive admixture system includes an air inlet valve, a fluid valve, an air valve, and a pump. The controller is configured to operate the additive admixture system to transition the additive admixture system between an additive addition mode, a drain mode, and a system clear mode. The controller transitions the additive admixture system into the additive addition mode and operates the pump until a desired amount of an additive is added to the mixer drum, transitions the additive admixture system into the drain mode for a predetermined amount of time in response to the desired amount of additive being added to the mixer drum, and transitions the additive admixture system into the system clear mode for a predetermined amount of time to clear stagnant fluid or built up mixture from the additive admixture system.

A mixing drum includes a body defining a head aperture and a discharge aperture opposite the head aperture, a head coupled to the body and extending across the head aperture, and a mixing element positioned within the volume and coupled to the body. The head and the body define a volume. The body is formed from at least a first section and a second section. The first section overlaps the second section.

A mixing drum includes a body defining a head aperture and a discharge aperture opposite the head aperture, a head coupled to the body and extending across the head aperture, a bearing member coupled to the body and defining a bearing surface surrounding the body, and a mixing element positioned within the volume and coupled to the body. The head and the body define a volume configured to contain a fluid mixture. The mixing element is configured to drive the fluid mixture toward the head when the drum is rotated in a first direction. The mixing element is configured to drive the fluid mixture towards the discharge aperture when the mixing drum is rotated in a second direction opposite the first direction. The head is made from a first material, and the body is made from a second material having a lesser density than the first material.

In accordance with one embodiment, a method is provided that includes providing a liquid nitrogen storage system configured to cool a supply of liquid nitrogen to a temperature below the vapor point of liquid nitrogen; coupling a piping system with the liquid nitrogen storage system to convey a portion of the supply of liquid nitrogen from the liquid nitrogen storage system; coupling the piping system with a liquid nitrogen control valve configured to control a flow of liquid nitrogen to at least one liquid nitrogen dispensing head; disposing the at least one liquid nitrogen dispensing head above a conveyance device operable to convey an aggregate stream of a concrete batching plant during use; and disposing the at least one liquid nitrogen dispensing head in a position to dispense an output flow of liquid nitrogen onto the aggregate stream of the concrete batching plant during use.