A concrete/cement resurfacing machine integrates a dust collection subsystem and an overlay mixing/distribution subsystem, enabling a single operator to steer the machine to a desired floor location and deposit mixed, cementitious overlay material. The combination of dust collection and overlay mixing saves considerable time and achieves improved results, eliminating the need for separate vacuum machines while reducing the risk that dust will be released as bags of dry ingredients are added to the mixing tank. A single propane engine powers a hydraulic pump, with fluid being routed to three separate hydraulic motors with associated control valves to provide for forward/reverse locomotion, bidirectional paddle mixing, and vacuum generation. The dust collection system is preferably a two-stage system including a vacuum collection tank and a HEPA filter.

The invention provides methods and compositions for treating wash water from concrete production with carbon dioxide. The treated wash water can be reused as mix water in fresh batches of concrete.

The invention provides methods and compositions for treating wash water from concrete production with carbon dioxide. The treated wash water can be reused as mix water in fresh batches of concrete.

A device and method for measuring slump of concrete in a hopper feeding a concrete pump. A slump sensor generates a signal from either an ammeter to measure current from a power source feeding an electric motor being configured to rotate an agitator shaft or a pressure gauge configured to measure hydraulic pressure in a hydraulic drive hose passing between a hydraulic pump and a hydraulic motor configured to rotate the agitator shaft. A controlling computer includes a memory in which an operating range may reside, the operating range being a range from a lower slump signal value corresponding to a lower limit of slump value to an upper slump signal value. The controlling computer generates an alert signal when the slump sensor signal falls outside of the operating range. In one embodiment, the controlling computer stops the concrete pump when the alert signal is detected.

Some implementations herein described improvements to concrete products and processes for producing concrete products that may provide a positive environmental impact and that can be stronger relative to the percent of cement used. Particular examples include improvements to zero-slump to near-zero-slump concrete mixture design, material storage and handling, batching, mixing, sequencing and curing processes, as well as forming and curing techniques.

Some implementations herein described improvements to concrete products and processes for producing concrete products that may provide a positive environmental impact and that can be stronger relative to the percent of cement used. Particular examples include improvements to zero-slump to near-zero-slump concrete mixture design, material storage and handling, batching, mixing, sequencing and curing processes, as well as forming and curing techniques.

A mixer vehicle includes a mixer drum, a first acceleration sensor, a second acceleration sensor, and a controller. The first acceleration sensor is configured to produce first acceleration signals and the second acceleration sensor is configured to measure accelerations within the mixer drum to produce second acceleration signals. The controller is configured to receive the first acceleration signals from the first acceleration sensor and second acceleration signals from the second acceleration sensor. The controller is further configured to determine a presence of material within the mixer drum based on the first acceleration signals and the second acceleration signals. The controller is further configured to determine one or more properties of the material within the mixer drum based on the first acceleration signals and the second acceleration signals.

A method for the use of a gaseous effluent containing a CO.sub.2 gas fraction and a non-CO.sub.2 gas fraction, including at a first location: providing liquid nitrogen at a temperature less than −196° C., and causing the gaseous effluent to contact the liquid nitrogen to as to capture at least part of the CO.sub.2 present in the CO.sub.2 gas fraction as a mixture of CO.sub.2 particles and liquid nitrogen. Conveying at least part of the mixture to a second location, and at the second location, bringing the mixture into contact with one or more ingredients of a wet concrete before and/or during and/or after the wet concrete is prepared by blending the ingredients of the wet concrete in a blender, so that the mixture extracts heat from said one or more ingredients of the wet concrete, and CO.sub.2 from the mixture partially carbonates Ca-compounds present in the wet concrete.

There is described a probe for monitoring fresh concrete received in a drum of a fresh concrete mixer. The probe generally has an electromechanical actuator having a frame mounted within the drum and a moving element actuatably mounted to the frame, the moving element having a fresh concrete interface exposed within the drum and experiencing a resistance to movement within the drum upon actuation of the electromechanical actuator with an electrical signal; and a measurement unit measuring a resistance response during the actuation and generating a response signal based on the measured resistance response, the generated response signal comprising monitoring Information concerning the fresh concrete within the drum, if any.

Embodiments disclose systems and methods to measure concrete mixer truck drum rotation. A camera (e.g., a video camera or Infra-Red (“IR”) camera) may capture images of a surface of a concrete mixer truck drum. A drum rotation measurement platform may receive the images of the surface of a concrete mixer truck drum captured by the camera and automatically analyze the captured images using machine learning technology to determine drum rotation information (e.g., a drum rotation speed and/or drum rotation direction). The drum rotation measurement platform may then output an indication of the determined drum rotation information. In some embodiments, the surface of the concrete mixer truck drum may include one or more marking symbols (e.g., of various shapes), and the automatic analysis performed by the drum rotation measurement platform includes detection of movement of the marking symbol between captured images.