A method for 3D printing a construction using a printing unit includes obtaining a precursor printing material, the precursor printing material including a binder, water, and sand; forming a flow of the precursor printing material towards the printing unit using a material pump; adding downstream of the material pump an amount of a first additive to the precursor printing material; optionally adding one or more additional additives; mixing the precursor printing material, the first additive and the optional one or more additional additives to form the printing material; and extruding the printing material via the printing head.

A method for manufacturing hydraulically hardening building materials, includes the steps of: providing concrete demolition waste with a maximum particle size of up to 150 mm as a starting material, mixing the starting material with water to form a feedstock slurry, introducing carbon dioxide or a precursor thereof into the feedstock slurry to form carbonated concrete fines in an amount from 1 to 100 wt.-% of the hardened binder contained in the starting material and to detach the concrete fines from the aggregate contained in the starting material to form a product slurry, and mixing the product slurry with a cement forming the building material,
and use of the obtainable building material for manufacturing building structures as well as method for manufacturing a supplementary cementitious material slurry.

A system and method for introducing a slurry mixture for making gypsum board is disclosed. The system includes, for example, a mixer, a foam injector, and a canister for mixing and moving a slurry mixture of foam and gypsum slurry. Also included in the system is an apparatus having a funnel body constructed and arranged to further mix the slurry mixture. The funnel body includes a number of baffles projecting from its inner wall towards a center and that are spaced around the inner wall. The baffles induce turbulence into the slurry mixture as the slurry mixture moves towards its outlet, thus further mixing the mixture and reducing the flow rate of the slurry mixture before its exits from the outlet for forming the gypsum board.

Provided herein are methods and compositions for carbonation of recycled concrete aggregates (RCA) to produce carbonated RCA. In addition, uses of the carbonated RCA, such as in building materials, and building materials containing RCA, are included. Carbonation of RCA may be used alone or may be used in combination with other carbonation processes associated with concrete manufacture, such as carbonation of wet concrete mixes and/or carbonation of concrete wash water.

The present invention is directed to a disk stack foamer system for controlling compressed air while making foam. From a bubble fluid and compressed air orifice, a first multi-orifice bulb discharges bubble fluid and compressed air while restricting air from expanding or amassing before entering a first disk stack. There are four chambers each containing two partitioned filter disk stacks. Disk stacks function progressively to each other in series. Downstream, discharged foam and compressed air run through a commercially available wye bubble reformer. In a cement and foam mixing wye, compressed air from the resistance of disk stacks is used by a second multi-hole bulb to temporarily separate foam in a comb-like fashion. A cement orifice slurry is able to wet against a majority of exposed foam, and thus make superior, homogeneous cementitious foam as discharged out of an application hose.

Apparatus, systems, and methods for preparing foam cement compositions in a laboratory are disclosed. The apparatus includes a blender body, a base connector, an inlet port, a test port, an outlet port, a blender blade apparatus, and a blender cap. Systems to prepare foam cement compositions in a laboratory, include the apparatus, a first tubing assembly threaded to the inlet port configured to receive a pressurized gas and provide the pressurized gas to the apparatus, a second tubing assembly threaded to the test port, and a motorized base. Methods for preparing a foam cement composition using the apparatus for preparing foam cement compositions in a laboratory include adding a cement composition to the apparatus, fitting a blender cap on the apparatus, mixing the cement composition, and providing a pressurized gas and surfactant to the cement composition to produce a foam cement composition.

Provided herein are methods and compositions for carbonation of recycled concrete aggregates (RCA) to produce carbonated RCA. In addition, uses of the carbonated RCA, such as in building materials, and building materials containing RCA, are included. Carbonation of RCA may be used alone or may be used in combination with other carbonation processes associated with concrete manufacture, such as carbonation of wet concrete mixes and/or carbonation of concrete wash water.

An apparatus (100) for the production of a plaster slurry is described, the apparatus (100) comprising a mixer (102) for mixing at least plaster and water to form a plaster slurry, the mixer (102) comprising an outlet conduit (122), a foam generator (106) for mixing at least air, a foaming agent and water to produce a foam, the foam generator (106) in fluid communication with the mixer (102) via a fluid pathway (116) comprising a foam conduit (117); and a mass flow meter (124), wherein the mass flow meter (124) is configured to measure the density and mass flow rate of the foam within the foam conduit (117) or the plaster slurry within the outlet conduit (122). Additionally, a method of manufacturing a plaster slurry is described.

According to the present invention, there is provided an apparatus (100) for manufacturing a cementitious slurry comprising foam, the apparatus (100) comprising a mixing chamber (101) for mixing a cementitious material and water to form a cementitious slurry, a channel (103) fluidly connected to the mixing chamber (101) at a first end (111), the channel (103) for receiving a cementitious slurry from the mixing chamber (101). In the apparatus, the channel (103) extends from the first end (111) and terminates at at least one second end (112). The channel (103) comprises a first foam inlet (106) for introducing foam into the channel (103), wherein the apparatus (100) is configured, in use, to introduce foam through the first foam inlet (106) at a velocity 5.4 times or less the velocity of the cementitious slurry in the channel (103). A method using the apparatus is also described.

Cellular concrete is formed from a cement-based wet mix slurry with a foam entrained into the wet mix. The foam is created using a foaming agent, mixed with water and air using a foam generator. The wet mix is mixed with the foam to form the cellular concrete wet mix. Poor component metering and blending practices in the current state of the art limits the performance capabilities of existing cellular concrete placements. The presently disclosed technology addresses this with a cellular concrete mixing system comprising a dry mix hopper to store a quantity of dry mix, a mixing tank to blend the dry mix and water together to form a wet mix, a holding tank to store a quantity of the wet mix, a foam generator to generate foam from air, water, and foam concentrate, and a blend controller to control operation of the overall mixing system.