The present invention pertains to the field of construction materials, and more specifically to a retaining wall block.
Retaining wall blocks and methods of manufacturing retaining wall blocks are known in the art. Prior art retaining wall blocks are generally heavy, because of their intended application, and are therefore expensive to manufacture.
In accordance with the present invention, a retaining wall block and method of manufacture are provided that result in a retaining wall block that is both lighter and less expensive.
In accordance with an exemplary embodiment of the present invention, a concrete block is provided. The concrete block includes a front face having a height H1 and a width L1. A lip is disposed underneath the front, and the lip has a height H3. A rear face of the concrete block has a height H2 and a width L2, wherein the rear face is shorter than the sum of H1 plus H3 by an amount H4, and wherein the sum of H1 plus H3 equals the sum of H2 plus H4. An upper surface of the concrete block forms a channel, such as a U-shaped channel.
Those skilled in the art will further appreciate the advantages and superior features of the invention together with other important aspects thereof on reading the detailed description that follows in conjunction with the drawings.
In the description that follows, like parts are marked throughout the specification and drawings with the same reference numerals. The drawing figures might not be to scale and certain components can be shown in generalized or schematic form and identified by commercial designations in the interest of clarity and conciseness.
Retaining wall block 100 includes front face 102, bottom face 104 and rear face 106. The upper surface 108 of retaining wall block 100 forms a channel that extends through one or more sidewalls and does not form a face, which allows fill material, such as rocks, gravel, or excavated dirt or soil, to be placed within the channel. The channel runs approximately parallel to the front and rear faces, and forms a cross section of the block from the front face to the back face that is approximately constant, as a function of normal manufacturing variations. In this manner, retaining wall block 100 is substantially prismatic along an axis extending approximately parallel to the channel. In this manner, the fill material provides additional mass to a retaining wall formed using plurality of retaining wall blocks 100, which adds stability to the retaining wall that would otherwise be provided by the additional mass of the retaining wall blocks. In addition, the use of fill material to increase the mass of retaining wall block 100 allows retaining wall block 100 to be manufactured at a lower cost from less raw materials while providing the same amount of mass when installed for use in retaining soil, dirt, rocks or other landscaping materials. Each retaining wall block 100 also costs less to ship on a per-unit basis than other retaining wall blocks, because it weighs less than other solid retaining wall blocks. Retaining wall block 100 also provides benefits over hollow retaining wall blocks, which provide the benefit of having a lower per-unit cost to manufacture and a lower shipping weight, but which are not capable of being filled with material during installation and which therefore do not provide a retaining wall with equivalent mass.
Retaining wall block 100 also includes lip 110 and shelf 112, which are configured to interlock with front top surface 116. The dimensions of lip 110 and shelf 112 can be varied as suitable, but in general, the depth of shelf 112 will usually be less than the thickness of the front section of retaining wall block 100, to prevent a retaining wall constructed from a plurality of blocks 100 from leaning forward when it is installed.
Front top surface 116 is shaped so as to fit with the contour of lip 110 of a mating retaining wall block 100, but can have other suitable forms that are easy to manufacture. Lip 110 may include a plurality of angled portions, so as to allow a mating retaining wall block to be placed in a number of different orientations, based on the design of a retaining wall. Likewise, lip 110 can be made straight and without the angled portions where desired. Retaining wall block 100 also includes rear top surface 118, rear bottom corner 114 and sidewalls 120 and 122.
Front face 102 of retaining wall block 100 can also or alternatively be textured. Texture can be applied by using a liner in the section of the mold corresponding to front face 102, where the liner can be attached using multiple links or hinges that allow the liner to rest securely against the sidewall of the mold during molding but to swing downward when the mold is raised, so as to disengage from the side of the retaining wall block.
In use, retaining wall block 100 can be used to build retaining walls that follow existing natural contours. Retaining wall block 100 can be filled with fill material, such as rock, gravel, material from the terrain where the retaining wall is being installed, or other suitable materials that allow retaining wall block 100 to be constructed at a lower cost from less material without a corresponding loss of mass, which is generally required to allow the retaining wall to withstand back pressure from the retained landscaping materials or soil without movement. In addition, the use of local terrain to fill retaining wall block 100 reduces the cost associated with installation, as there will be less displaced earth to be removed. Retaining wall block 100 can also be used with anchors, as further described herein, such as for applications where the back pressure from the retained landscaping materials or material may be high enough to cause the retaining wall to be unstable.
When an angular disposition is provided for one or both of sidewalls 120 and 122 such that L2 is less than L1, retaining wall block 100 can be installed so as to follow a curved landscape feature. In addition, anchors can be used in conjunction with retaining wall block 100 when L2 is less than L1, such as by disposing the anchors between the gaps in adjacent blocks. Because retaining wall block 100 is formed on its side, the width of the front and rear faces will need to be controlled using a stripper shoe that is disposed at an angle during the molding process, as described herein.
In addition, side view 400 also shows the channel formed by upper surface 108, which can be filled with rock, gravel, excavated materials or other suitable materials to provide additional mass for a retaining wall, and which also allows the amount of excavated material that must be disposed of to be reduced. Anchor structures such as cross-connected rebar or other suitable materials can be disposed in the channel, or geogrid or fabric materials can be lined along upper surface 108 and trailed behind rear face 106, prior to filling the channel with fill material.
Front view 600 also includes an anchor support 506, which is connected to anchors 504 by welding, bolts or in other suitable manners. Anchor support 506 is placed within the cavities formed by upper surfaces 108 of retaining wall blocks 100, and anchors 504 extend through gaps 502 between the retaining wall blocks 100. In one exemplary embodiment, anchor support 506 can be placed within the cavities of a first course of retaining wall blocks 100, and anchors 504 can then be placed in gaps 502 between the retaining wall blocks 100 and attached to anchor support 506 by welding, bolts or in other suitable manners. Fill dirt can then be placed within the cavities, and anchors 504 can be covered with a layer of excavated earth. Anchors 504 and also or alternatively be driven into the earth behind the course of retaining wall blocks 100. After a first course of retaining wall blocks is constructed, a second course can then be constructed on top of the first course. Successive courses can then be installed in the same manner to form a retaining wall.
Mold 800 is configured for use in a dry cast molding process. Dry cast material is placed within mold cavities 804 and 806. The dry cast material is pressed, under vibration, into place by a stripper shoe compression head (not explicitly shown), which is inserted into mold cavities 804 and 806. The stripper shoe compression head can be angled to provide a difference between L1 and L2 as shown in
In operation, mold 800 increases the efficiency of the manufacturing process for retaining wall blocks by increasing the number of blocks that can be made in a unit space. Unlike prior art blocks that are not capable of being nested, retaining wall blocks 100 can be nested in mold 800, which results in greater efficiency during the molding process.
Wall thickness T of retaining wall blocks 1002 and 1004 does not need to be uniform as long as other critical dimensions are maintained, but is generally determined based on the material characteristics of the concrete or other masonry materials that is being used to manufacture the retaining wall blocks. Because retaining wall blocks 1002 and 1004 are used to minimize the amount of concrete or other masonry material that is needed to manufacture the retaining wall blocks, in order to reduce the per-block cost of each retaining wall block and associated shipping weight, the wall thickness will typically be uniform.
Because retaining wall blocks 1002 and 1004 have an opening in the top and inner channel, a cap can also be used to provide an aesthetically-pleasing top surface to a completed retaining wall. In order to provide a “capless” retaining wall block, such that an additional cap block does not need to be manufactured or kept in stock, the rear face can be broken off at break point X to allow fill material to be uniformly provided up to the rear surface of the front wall. In addition, a notch or other feature can be provided at break point X to make it easier to break off the rear face, although such features might also result in greater inadvertent breakage. Based on the material strength of concrete and other masonry materials, another block or other common construction equipment such as a hammer should be sufficient to allow the rear face to be easily broken off by construction personnel without the need for a break point notch.
A mold liner can be utilized to provide an embossed front face 1026, where suitable. Such mold liners are typically attached to one side of the mold by hinges or links, and swing away from the molded block when the mold is lifted off the block.
Although exemplary embodiments of a system and method of the present invention have been described in detail herein, those skilled in the art will also recognize that various substitutions and modifications can be made to the systems and methods without departing from the scope and spirit of the appended claims.