An additive injection system can be a part of a cementitious slurry mixing and dispensing assembly. The additive injection system can be used to inject an additive into an auxiliary slurry discharge conduit carrying a secondary flow of cementitious slurry produced in the assembly such that the secondary slurry stream is different from a main slurry stream discharged from a main slurry discharge conduit.

A mixing assembly includes a main flow conduit having an inlet end and an opposite outlet, a source of pressurized air at the inlet end, a container of stucco in fluid communication with the flow conduit, and a source of water in fluid communication with the flow conduit between the outlet and the container. The pressurized air draws stucco from the container into the flow conduit, and also draws water into the flow conduit to form an atomized slurry.

A mixing assembly includes a main flow conduit having an inlet end and an opposite outlet, a source of pressurized air at the inlet end, a container of stucco in fluid communication with the flow conduit, and a source of water in fluid communication with the flow conduit between the outlet and the container. The pressurized air draws stucco from the container into the flow conduit, and also draws water into the flow conduit to form an atomized slurry.

A shotcrete nozzle assembly comprising: a tubular body operatively connectable to a concrete source, the tubular body including a stream controlling section for controlling a stream of fresh concrete projected from an outlet body end, the stream controlling section including at least one helicoidal conduit defined within the body sidewall, each helicoidal conduit extending helicoidally around a central conduit between an air inlet end operatively connectable to a pressurized air source and an air outlet end located towards the outlet body end, each helicoidal conduit being twisted around the central passageway to guide pressurized air exiting through the air outlet end along an helicoidal path extending away from the outlet body end and around the stream of fresh concrete exiting the outlet body end.

A shotcrete nozzle assembly comprising: a tubular body operatively connectable to a concrete source, the tubular body including a stream controlling section for controlling a stream of fresh concrete projected from an outlet body end, the stream controlling section including at least one helicoidal conduit defined within the body sidewall, each helicoidal conduit extending helicoidally around a central conduit between an air inlet end operatively connectable to a pressurized air source and an air outlet end located towards the outlet body end, each helicoidal conduit being twisted around the central passageway to guide pressurized air exiting through the air outlet end along an helicoidal path extending away from the outlet body end and around the stream of fresh concrete exiting the outlet body end.

Systems and methods related to preparing foamed cement for laboratory analysis are provided. A prepared cement slurry is placed in a cement reservoir cell configured to pressurize the cement slurry contained within the cement reservoir cell to a capture pressure. After pressurization, the cement slurry and a compressed gas are introduced into a foam generator. Foamed cement generated in the foam generator is introduced from the tee into a foam capture cell where it can cure prior to analysis.

Systems and methods related to preparing foamed cement for laboratory analysis are provided. A prepared cement slurry is placed in a cement reservoir cell configured to pressurize the cement slurry contained within the cement reservoir cell to a capture pressure. After pressurization, the cement slurry and a compressed gas are introduced into a foam generator. Foamed cement generated in the foam generator is introduced from the tee into a foam capture cell where it can cure prior to analysis.

A system for preparing a dry process material includes a sealed container that holds and seals the dry process material therein and prevents airborne dust or particles from the dry process material from escaping the sealed container. Sealed processing equipment receives the dry process material from the sealed container and prevents the airborne dust or particles from escaping the sealed processing equipment. A sealed connection sealingly couples the sealed container to the sealed processing equipment and prevents the airborne dust or particles from escaping while transferring the dry process material. A sealed transfer conduit is sealingly coupled to and extends from the sealed processing equipment.

A dry mineral binder composition includes cement and mineral fillers for the manufacture of molded parts by way of 3D printing. The binder composition additionally contains at least one aluminum sulfate-based accelerator, at least one polycarboxylate ether-based super-plasticizer and at least one rheology additive.

Methods, systems, and devices, are developed for in-situ placement of a concrete mix that can have the thixotropy to hold vertical dimension without containment, while maintaining pliability to be pumped into place and manipulated to a desired shape, and can be combined with concrete set accelerators, allowing subsequent layers of this concrete mix to be continuously stacked in place to build tall walls and such without the use of forms. Concrete without these special properties is pumped toward the point of placement where it is modified by injecting and mixing, into that line of pumped concrete, an admixture containing thixotropes, thickeners and/or set accelerators or other modifiers to provide these properties and other improvements. This method allows conventional plant batching with commonly available constituent materials for batching an economical concrete that is delivered to a jobsite and then is pumped most of the way to a point of placement.