The present invention provides a wet press process and admixture components for making concrete slabs (flags), curb (kerb) units, panels, boards, and other flat shapes, whereby colloidal silica and at least one alkanolamine and optional rheology control components are employed to provide an ideal combination of pressing time, green strength, surface definition, stack-ability, final concrete strength, and permeability. Stack-ability can be expressed in terms of minimum deflection or non-eccentricity of the units while standing on thickness edges at distances apart less than width or standing height. A wet press process typically involves introducing a highly fluid concrete mix into a mold, applying hydraulic pressure to consolidate the concrete (e.g., 1000-3000 PSI) and to extract excess water, removing the pressed concrete while in a green state from the mold, and then standing the slab units immediately upon removal from the mold while in a green state, on an edge adjacent to but spaced apart from other edge-standing units. In further embodiments, rounded aggregates such as naturally occurring sand and/or gravel obtained from local sources can be incorporated into the concrete slabs without defeating (vertical) stack-ability in the green state.

A form for separating a concrete block and a method for separating a concrete block from the form. The formed concrete block remains stationary while the doors of the form are pulled away from the concrete block in order to more conveniently, efficiently, and safely obtain access to the formed concrete block for its removal.

A form for separating a concrete block and a method for separating a concrete block from the form. The formed concrete block remains stationary while the doors of the form are pulled away from the concrete block in order to more conveniently, efficiently, and safely obtain access to the formed concrete block for its removal.

The present invention provides a wet press process and admixture components for making concrete slabs (flags) (16), curb (kerb) units, panels, boards, and other flat shapes, whereby colloidal silica and at least one alkanolamine and optional rheology control components are employed to provide an ideal combination of pressing time, green strength, surface definition, stack-ability, final concrete strength, and permeability. Stack-ability can be expressed in terms of minimum deflection or non-eccentricity of the units while standing on thickness edges at distances apart less than width or standing height. A wet press process typically involves introducing a highly fluid concrete mix into a mold (10,12), applying hydraulic pressure to consolidate the concrete (e.g., 1000-3000 PSI) and to extract excess water, removing the pressed concrete (16) while in a green state from the mold (10,12), and then standing the slab (16) units immediately upon removal from the mold (10,12) while in a green state, on an edge adjacent to but spaced apart from other edge-standing units. In further embodiments, rounded aggregates such as naturally occurring sand and/or gravel obtained from local sources can be incorporated into the concrete slabs without defeating (vertical) stack-ability in the green state.

The present invention provides a wet press process and admixture components for making concrete slabs (flags) (16), curb (kerb) units, panels, boards, and other flat shapes, whereby colloidal silica and at least one alkanolamine and optional rheology control components are employed to provide an ideal combination of pressing time, green strength, surface definition, stack-ability, final concrete strength, and permeability. Stack-ability can be expressed in terms of minimum deflection or non-eccentricity of the units while standing on thickness edges at distances apart less than width or standing height. A wet press process typically involves introducing a highly fluid concrete mix into a mold (10,12), applying hydraulic pressure to consolidate the concrete (e.g., 1000-3000 PSI) and to extract excess water, removing the pressed concrete (16) while in a green state from the mold (10,12), and then standing the slab (16) units immediately upon removal from the mold (10,12) while in a green state, on an edge adjacent to but spaced apart from other edge-standing units. In further embodiments, rounded aggregates such as naturally occurring sand and/or gravel obtained from local sources can be incorporated into the concrete slabs without defeating (vertical) stack-ability in the green state.

Embodiments of a mold for making a retaining wall blocks are disclosed. The mold enables blocks to be made more quickly by enabling separation of each block from the mold housing when the block is cured sufficiently to enable separation. Once separated, the block can be permitted to fully cure away from the mold housing, while the mold housing is re-used to produce one or more other blocks. In one embodiment, among others, the mold has a movable bottom tray and a mold housing with at least one door. The mold housing has an opening designed to receive and introduce a fabrication material, such as concrete, into the cavity. Once a block is sufficiently cured, it is separated from the mold housing on the tray through the at least one door, and a new tray is inserted in the mold housing to make another block.

Embodiments of a mold for making a retaining wall blocks are disclosed. The mold enables blocks to be made more quickly by enabling separation of each block from the mold housing when the block is cured sufficiently to enable separation. Once separated, the block can be permitted to fully cure away from the mold housing, while the mold housing is re-used to produce one or more other blocks. In one embodiment, among others, the mold has a movable bottom tray and a mold housing with at least one door. The mold housing has an opening designed to receive and introduce a fabrication material, such as concrete, into the cavity. Once a block is sufficiently cured, it is separated from the mold housing on the tray through the at least one door, and a new tray is inserted in the mold housing to make another block.

Masonry units, such a blocks, are fabricated in a sequential process, using improved mold structures, such as within a production corridor of a corresponding fabrication system. A compressible masonry feedstock or formula, which can be de-agglomerated before use, is filled within a block mold having releasable elements. The formula is then compressed within the mold structure. The compressed workpiece can be further processed, such as for any of final height adjustment, the establishment of a surface feature, or to remove cores. The block mold, having releasable elements or sides, such as using hinges or springs, is released from the formed block, wherein the formed masonry unit can be removed for curing, and wherein the block mold can be reused to fabricate a subsequent masonry unit.

Masonry units, such a blocks, are fabricated in a sequential process, using improved mold structures, such as within a production corridor of a corresponding fabrication system. A compressible masonry feedstock or formula, which can be de-agglomerated before use, is filled within a block mold having releasable elements. The formula is then compressed within the mold structure. The compressed workpiece can be further processed, such as for any of final height adjustment, the establishment of a surface feature, or to remove cores. The block mold, having releasable elements or sides, such as using hinges or springs, is released from the formed block, wherein the formed masonry unit can be removed for curing, and wherein the block mold can be reused to fabricate a subsequent masonry unit.

Disclosed is a deagglomeration apparatus, to improve the quality of a mixture used for the production of concrete blocks. An illustrative embodiment of the deagglomerator comprises a vertical shaft high-shear mixer, wherein a rotational force (hydraulic or electric) is mounted to a vertical shaft onto which are mounted chains and/or knives, housed within a flexible rubber boot or tube. The deagglomerator is configured to be controllably powered, to rotate the shaft and the attached tools. Partially mixed formula is introduced to a top region of the deagglomerator, and falls downwardly past the rotating tools wherein the formula is pulverized and mixed, before exiting the lower area of the mixing region.