Abstract: A mold assembly and method for molding two concrete blocks in face-to-face non-contacting relationship forms blocks having smooth front faces. The mold assembly includes a mold box having two mold cavities configured to form two blocks in face-to-face non-contacting relationship. A common partition plate separates the two mold cavities and opposite sides of the partition plate form the smooth front faces of the blocks. The two mold cavities are each configured to form a block having a raised front face with a beveled edge around its entire perimeter and a border around the entire perimeter of the beveled edge. The portions of the border at the top and the sides of the raised front face are curved and the portion of the border at the bottom of the raised front face is straight. A core bar is slidably inserted into the mold box beneath the bottom of the partition plate, and opposite sides of the core bar extend into and form the front bottom portions of the mold cavities.

Abstract: A mine safety dust exhibiting improved dispersion in water. The rock dust includes dolomitic limestone particles which, when mixed at the mine site to form a slurry, stay in suspension during intermittent operation of spray machinery and with a reduced need for continuous mixing. The rock dust composition includes an inorganic salt that acts as a dispersant to improve dispersion of the rock dust in water and further acts as a deflocculant to keep the dust particles in suspension in the resultant slurry.

Abstract: A mine safety dust exhibiting improved dispersion in water. The rock dust includes dolomitic limestone particles which, when mixed at the mine site to form a slurry, stay in suspension during intermittent operation of spray machinery and with a reduced need for continuous mixing. The rock dust composition includes an inorganic salt that acts as a dispersant to improve dispersion of the rock dust in water and further acts as a deflocculant to keep the dust particles in suspension in the resultant slurry.

Abstract: A wall construction system including plurality of interlocking concrete blocks. The interlocking blocks include one or more stretcher blocks, corner blocks, and half blocks. The blocks include top and end shear lugs and bottom and end grooves. The bottom grooves accommodate the top shear lugs of blocks in a lower course of stacked blocks. Corner blocks provide a means for creating a corner and turning the direction of a course of blocks by 90 degrees. The interlocking features of the blocks enable dry-stacking in successive courses to construct a wall or multi-wall structure. When stacked end to end in successive rows, the top and end shear lugs of each interlocking block engage complimentary grooves in the underlying, overlying, and adjacent blocks thereby enabling the blocks to rapidly self-align vertically and lock together as they are stacked. The resulting dry-stacked structure exhibits a high lateral resistance to overpressures or transverse loads.

Abstract: A mine seal or wall capable of retaining its integrity under a transverse load. The mine seal is constructed of a plurality of interlocking masonry blocks. The interlocking blocks include a body with a top surface, planar sides, planar ends, and a bottom surface. A top shear lug extends longitudinally along the top of the block. An end shear lug extends vertically along each end of the block. The bottom surface and each end of the block includes a groove therein. When stacked end to end in successive rows, the top and end shear lugs of each interlocking block engage the complimentary grooves in the adjacent blocks thereby enabling the blocks to self-align vertically and lock together as they are stacked. The resulting mine seal exhibits a high resistance to transverse loads.

Abstract: A corner block has spaced-apart front and rear sections interconnected by two spaced-apart side sections that jointly define an internal cavity. Upper protrusions are provided on the top face of the block, and inner protrusions are provided inside the cavity at the bottom of the block. The upper and inner protrusions are configured and arranged relative to one another so that when two corner blocks are stacked one atop another with one block rotated 90° relative to the other, the upper protrusions of the lower block interlock with the inner protrusions of the upper block to interlock the two blocks. The corner blocks are constructed in two variants, a corner block A and a corner block B, which are mirror images of each other. The corner blocks A and B are alternately stacked upon one another to construct a 90° corner of a segmental wall structure.

Abstract: A mine seal or wall capable of retaining its integrity under a transverse load. The mine seal is constructed of a plurality of interlocking masonry blocks. The interlocking blocks include a body with a top surface, planar sides, planar ends, and a bottom surface. A top shear lug extends longitudinally along the top of the block. An end shear lug extends vertically along each end of the block. The bottom surface and each end of the block includes a groove therein. When stacked end to end in successive rows, the top and end shear lugs of each interlocking block engage the complimentary grooves in the adjacent blocks thereby enabling the blocks to self-align vertically and lock together as they are stacked. The resulting mine seal exhibits a high resistance to transverse loads.

Abstract: A double-wall structure, such as a fence wall or a parapet wall, has two back-to-back walls each constructed of successive courses of concrete wall blocks dry-stacked one atop another with each succeeding course set back relative to the immediately preceding course so that the two walls converge upwardly towards one another and are capped at the top by cap blocks. Each wall block has protuberances that protrude upwardly from the top face of the block and a groove provided in the bottom face thereof. The groove is located and dimensioned relative to the protuberances so that the grooves of wall blocks in each succeeding course engage with the protuberances of wall blocks in the immediately preceding course to establish the setback distance between abutting courses of wall blocks.

Abstract: A cap block has opposed top and bottom major faces bounded by two opposed side faces and two opposed end faces. The bottom face has two grooves that extend lengthwise in a side-to-side direction of the cap block from one side face to the other side face. The two grooves are spaced apart from one another in an end-to-end direction of the cap block so that the cap block can be positioned atop and cap two back-to-back walls of wall blocks with each groove receiving therein protuberances that protrude upwardly from top faces of uppermost wall blocks of respective ones of the two walls. The cap block is manufactured by molding a dry-cast concrete mixture in a mold cavity having the shape of the cap block with a base of the mold cavity corresponding to one side face of the cap block.

Abstract: A lightweight concrete masonry unit for veneering the face of a building. The veneer block includes a body with planar front, top, bottom, and side surfaces with the top, bottom, and sides perpendicular to the front surface. One or more channels are formed in the rear surface. The depth of the channels are restricted to maintain no less than one inch of remaining wall thickness between the channel bottoms and the opposite front surface. The novel shape and larger minimum wall thickness of the lightweight veneer block enables production on a commercial block machine within the standard cycle time, provides weight and raw material cost savings up to 50%, and allows block heights that are not attainable with conventional hollow core veneer blocks.

Abstract: A corner block has spaced-apart front and rear sections interconnected by two spaced-apart side sections that jointly define a through-cavity that extends through the block from a top face thereof to a bottom face. Upper protrusions are provided on the top face of the block, and lower protrusions are provided inside the cavity at the bottom of the block. The upper and lower protrusions are configured and arranged relative to one another so that when two corner blocks are stacked one atop another with one block rotated 90 degrees relative to the other, the upper protrusions of the lower block interlock with the lower protrusions of the upper block to interlock the two blocks. The corner blocks are constructed in two variants, a corner block A and a corner block B, which are mirror images or opposite hands of each other. The corner blocks A and B are alternately stacked upon one another to construct a 90-degree corner of a segmental retaining wall or other wall structure.

Abstract: A retaining wall block has spaced-apart front and rear sections interconnected by two laterally spaced-apart side sections that jointly define a through-cavity that extends through the block from a top face thereof to a bottom face thereof. Two or more protuberances protrude outwardly from the top face of the front section frontwardly of the through-cavity. A groove extends laterally in the bottom face of the front section frontwardly of the through-cavity. The groove is located and dimensioned relative to the protuberances so that two blocks can be stacked one atop another in staggered relation with one or more protuberances of the lower block engaged with one but not both of a front wall and a rear wall of the groove of the upper block and the upper block setback with respect to the lower block.

Abstract: A method for forming a masonry unit that includes joining a pallet to a bottom surface of a mold, inserting a filler plug into the side of the mold between a partition plate and a pallet, dispensing mix into the mold, and compressing the mix with a shoe to form a masonry unit with a filler plug effect.

Abstract: A block for use in constructing a retaining wall and comprising a body having a central cavity extending vertically there through and defining front, rear, and side walls. The side walls diverge rearwardly from the front of the block to the rear. Stabilizing wings extending outwardly at the rear of the side walls. Positioning wedges extend from the bottom surface and include flat forward surfaces for positioning the block with respect to the blocks in a lower tier of blocks. The flat forward surfaces of the positioning wedges are located nearer the front surface of the block than is the inner surface of the front wall, thereby enabling a retaining wall created from the blocks to have each successive higher tier offset from the adjacent lower tier by a set distance. The block of the present invention provides a stable block having a large coverage area at a low weight.

Abstract: A prefabricated cribbing column for supporting a mine roof. The column includes a plurality of concrete cribbing elements the majority of which are interleaved with load transfer disks. Two of the cribbing elements are interleaved with a handle element. The column assembly of cribbing elements, load transfer disks, and handle element are secured together in an integral unit by a steel strap. The handle element extends substantially beyond the outer periphery of the cribbing elements enabling access and lifting by a forklift or similar machinery. The handle element enables the integral column to be easily moved from one location to another. The cribbing elements are preferably constructed of steel fiber reinforced concrete. A column consisting of five cribbing elements has shown to be capable of supporting a load of 575 tons with a deflection of 2.5 inches or less.