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 mixer having i) a vessel defining a mixing chamber surrounded by boundary walls for receiving a mixture containing lumps therein, ii) a plurality of mixing blades, and iii) a driving mechanism supporting the mixing blades in the mixing chamber for mixing motion relative to the vessel so as to mix the mixture within the mixing chamber of the vessel, further includes at least one lump conditioning blade. The lump conditioning blade is supported by the driving mechanism such that the lump conditioning blade is movable in a working direction along a respective one of the boundary walls with a working edge of the blade being maintained at a prescribed space from the boundary wall which is effective to reduce a lump size of the lumps in the mixture as the mixture passes between the working edge of the lump conditioning blade and the boundary wall.

The invention provides methods and compositions for carbonation of a wet cement mix. The wet cement mix may be carbonated prior to addition of aggregates, admixture, SCM, and/or other components to produce a carbonated concrete mix. The methods and compositions may include high shear mixing of a cement or concrete mix, either during or before carbonation.

The present invention relates to an apparatus for producing rapid-hardening concrete and a method for producing same, the rapid-hardening concrete being produced by intermixing and dissipating air in normal concrete and adding an early-strength admixture thereto. With respect to forming rapid-hardening concrete, mixed concrete is formed by mixing in a large volume of air bubbles to be discarded, along with an early-strength admixture, to already mixed normal concrete, the early-strength admixture getting evenly dispersed therewithin by means of the ball bearing effect of the air bubbles, and when the mixed concrete is discharged, a rapid-hardening concrete is shotcreted while excess air contained in the mixed concrete is dissipated by means of high-performance air, the slump which was raised due to the large amount of air bubbles having been reduced to the slump range for normal concrete.

A tubular admixture piece for receiving in a mixing device for controlled metering in of an adjuvant into a pumpable mixture has at least one sealing element for producing an at least partially fluid-tight connection between the admixture piece and the mixing device wherein the at least one sealing element is designed as an axial seal with respect to a longitudinal axis of the tubular admixture piece. A housing element of a mixing device has at least a sealing support for axial sealing of the admixture piece, and is also configured to exert a force that acts on the admixture piece in the axial direction and/or longitudinal direction of the through-flow opening, such that the axial seal of an admixture piece received at least partially in the through-flow opening can be pressed against the sealing support by the force.

Hemihydrate and/or anhydrous Type III gypsum granules derived from wasted gypsum boards are fed into a flow path of an aqueous gypsum slurry containing dihydrate gypsum, are mixed with the gypsum slurry, and are fed into a deposition tank of dihydrate gypsum. The gypsum slurry is fed from an inlet of the flow path, and the hemihydrate and/or anhydrous type III gypsum granules derived from wasted gypsum boards are fed into the gypsum slurry from above. The gypsum slurry after mixing is made to flow to an outlet of the flow path while the upper surface of the gypsum slurry is always exposed to air. The gypsum slurry is fed into a pipe by free fall. The gypsum slurry is made to impinge on the far side of the pipe as viewed from the outlet and fall or to fall down the center portion of the pipe. The generation of gypsum scale is suppressed in the mixing device for mixing gypsum granules derived from wasted gypsum boards with gypsum slurry.

The fiber boxes (60) each contain fiber (62) and are removably mounted to a fiber injector (9) for injecting the fiber (62) into a material flow stream. The fiber boxes (60) each have an enclosure (61) for containing the fiber (62), preferably a single fiber (62). An aperture 70 provides a feed hole (70) for passing the fiber (62) from an interior of the enclosure (61) to an exterior of the enclosure (61). Contacts (64) having ends disposed on an exterior of the enclosure (61), spaced apart for registering with mating contacts (54) on a fiber distribution ring (40). A frangible element (68) extends between the contacts (64) and provides electrical continuity between the two contacts (64), such that when the fiber (62) is fully withdrawn from within the enclosure (61) the frangible element (68) separates and breaks electrical continuity between the two contacts (64).

Disclosed is an apparatus and method for manufacturing high-performance concrete by introducing air into normal concrete and dissipating air, wherein high-performance concrete is formed in a manner in which bubbles, which are to be removed, are added in a large amount together with an admixture to pre-blended normal concrete so that the admixture is uniformly dispersed in the normal concrete using the ball-bearing effect of the bubbles, thus forming mixed concrete, and the mixed concrete is discharged using air at a high pressure of 5 atom or more to thereby shoot high-performance concrete of which the slump, remarkably increased due to the large amount of bubbles, is reduced to fall within the range of slump of normal concrete while dissipating excess air from the mixed concrete.

A portable mixing apparatus for mixing components is disclosed. The apparatus comprises a container for receiving components to be mixed, a frame for supporting the container in a first orientation for mixing components and a driving assembly couplable with the container for rotating the container. The frame comprises: a first handle for gripping with a first hand of a user, the first handle being disposed above a centre of mass of the portable mixing apparatus, when orientated in the first orientation, the first handle extending forwardly of the apparatus over the container; a second handle for gripping with a second hand of the user while the first hand grips the first handle, the second handle being disposed below the centre of mass of the portable mixing apparatus when orientated in the first orientation, the first and second handle being arranged to enable the user to carry the mixing apparatus and re-orientate the apparatus between the first orientation and a second orientation for emptying the components from the container.

A process and system are provided for preparing seed mixes having a target quantity and a target ratio of different types of seeds. The process generally includes portioning quantities of different types of seeds from bulk supplies of the seeds, and combining the portioned quantities of seeds to prepare the seed mixes. The system generally includes first and second dispensing assemblies for portioning the quantities of the different types of seeds from the bulk supplies, and a mixing assembly for receiving the portioned quantities of seeds as the seed mixes. The combined quantities of the different types of seeds in the seed mixes are substantially equal to the target quantity, and a ratio of the quantities of the different types of seeds is substantially equal to the target ratio.