Low elevation wall construction

Abstract
A retaining wall construction comprises modular facing blocks connected by fasteners to anchoring blocks positioned behind the facing blocks. The facing blocks are arranged in courses which overlap one another. The facing blocks, as well as the anchor blocks, have hollow, vertical throughbores. This enables interconnection of the back wall of the facing block with the anchor block by means of various types of fasteners. The retaining wall construction is especially useful in the construction of low height, gravity type walls.
Description

BACKGROUND OF THE INVENTION
This invention relates to an improved retaining wall construction and, more particularly, to a construction which is especially useful as a lower height, gravity wall.
Utilization of precast blocks for construction of gravity walls and other forms of earth retaining embankments is taught in various prior art patents.
These patents depict various types of precast blocks in combination with various types of anchoring or stabilizing elements and compacted earth in order to provide a retaining wall construction. The facing blocks for such constructions often have a very complex shape thereby rendering the block casting operation complex or difficult and also rendering manipulation of the blocks cumbersome and/or difficult. Thus, there has developed a need, especially with respect to walls having a lower height, to provide a methodology for construction of a wall using precast concrete blocks of simple configuration in combination with anchoring and other elements, also having a simple configuration. Also, the blocks should be light weight and easy to manipulate and assemble.
SUMMARY OF THE INVENTION
Briefly, the present invention comprises a retaining wall construction which fabricated from a plurality of generally modular facing blocks arranged in horizontal layers or courses with the vertically adjacent blocks overlapping one another, at least in part, to define a mosaic pattern. The blocks are precast and have a generally rectangular front face, a hollow core or vertical throughbore, a back wall and generally converging side walls. Attached to the back wall are anchoring blocks which are typically precast, rectangular parallelpiped concrete blocks having vertical throughbores. The sides of the anchoring blocks are positioned against the back wall of the facing blocks and retained there by straps or other types of fasteners. A series of anchoring blocks may be connected to one another to define an anchor or reinforcing element which is maintained within earth or particulate material compacted on the back side, of the gravity wall. Various types of fasteners are disclosed for connecting the blocks to one another. Various arrangements for stacking the blocks relative to each other and in combination are also disclosed. Constructions for corners, as well as a cap block arrangement are also disclosed.
Thus it is an object of the invention to provide an improved retaining wall construction comprised of simple, easily handled component parts.
It is a further object of the invention to provide an improved retaining wall construction which is economical to assemble and wherein the component parts are very economical to make.
Yet a further object of the invention is to provide an improved retaining wall or gravity type wall which is especially useful for the construction of lower height retaining walls.
Another object of the invention is to provide an improved retaining wall construction which is fabricated from easily manufactured component parts as well as component parts which are readily available.
These and other objects, advantages and features of the invention will be set forth in greater detail below.





BRIEF DESCRIPTION OF THE DRAWING
In the detailed description which follows reference will be made to the drawing comprised of the following figures:
FIG. 1 is a cut-away, exploded isometric view of a typical retaining wall construction of the invention;
FIG. 2 is a top plan view of a wall of the type shown in FIG. 1, wherein a right angle corner is incorporated in the wall;
FIG. 3 is a side elevation of a wall of the type shown in FIG. 1;
FIG. 4 is a front elevation of a wall of the type shown in FIG. 1;
FIG. 5 is a top plan view of a wall construction wherein a convex curve is incorporated in the wall, and a soil reinforcing element is attached to the blocks;
FIG. 6 is a top plan view of a wall of the invention wherein a concave curve is incorporated therein;
FIG. 7 is a front plan view of a typical facing block used to practice the invention;
FIG. 8 is a top plan view of a typical facing block used to practice the invention;
FIG. 9 is a rear plan view of the facing block of FIG. 7;
FIG. 10 is a top plan view of a typical anchor block used to practice the invention;
FIG. 11 is an end view of the anchor block of FIG. 10;
FIG. 12 is a side view of the anchor block of FIG. 10;
FIG. 13 is a top plan view of an alternate anchor block;
FIG. 14 is an end view of the block of FIG. 13;
FIG. 15 is a side view of the block of FIG. 13;
FIG. 16 is an isometric view of a typical clip or fastener used to attach separate facing and/or anchor blocks together;
FIG. 17 is an isometric view of an alternate clip or fastener;
FIG. 18 is a front elevation of ,the clip of FIG. 17;
FIG. 19 is a side elevation of the clip of FIG. 17;
FIG. 20 is an isometric view of a second alternate clip design;
FIG. 21 is a front view of a third alternate clip design;
FIG. 22 is a side view of the clip of FIG. 21;
FIG. 23 is a top view of a further alternate fastener design;
FIG. 24 is an isometric view of the fastener of FIG. 23;
FIG. 25 is an isometric view of a flexible strap used as a fastener to connect adjacent blocks;
FIG. 26 is a side view of the strap of FIG. 25; and
FIG. 27 is an isometric view of a final alternate fastener.





DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Overview
FIGS. 1 through 4 provide a general overview of the gravity wall or retaining wall of the invention. The wall is typically positioned on a footing or compacted, horizontal surface 30. The wall is comprised of horizontal rows of front facing blocks 32 (one block of each row marked, as examples) which are arranged in layers or courses on top of one another. Most typically, the facing blocks 32 of vertically adjacent layers or courses overlap one another laterally, at least in part, as best seen in FIG. 4. Generally the blocks 32 are not set back, but rather are stacked with their front faces defining a planar surface. They may, however, be set back.
The facing blocks 32 are connected to anchor blocks 34 (one block of each row marked, as representative) attached to the back side or back wall 68 (see FIG. 2; one back wall marked, as representative) of selected facing blocks 32. The anchor blocks 34 are interconnected by means of fasteners or clips 36 (one clip of each row marked, as representative). The facing blocks 32 include throughbores 70 (see FIG. 2; one representative throughbore marked) into which gravel or other particulate material is placed. The anchor blocks 34 are attached to selected layers or courses of facing blocks 32 and are surrounded by compacted particulate material 38 (see FIGS. 1 and 3). The entire assembly is built up in courses or layers and the blocks 32 of the top course constitute cap blocks 40 (see FIG. 4) defining a cap of the retaining wall construction.
The facing blocks 32, as well as the anchor blocks 34, may be fabricated from dry cast concrete. The facing blocks 32 as well as the anchor 34 blocks are generally modular and generally the size of typical concrete blocks so that they may be easily manually manipulated. The facing blocks 32 are of a simple design which can be easily cast and easily manipulated into a position to form the wall. The face of the facing blocks 32 may be textured or otherwise shaped in a desired configuration.
The facing blocks 32 may be vertically connected by positioning rods, stakes or other members 42 (see FIG. 3; one representative member marked) in the hollow spaces of adjacent blocks 32. The facing blocks 32 may be horizontally connected by means of rigid horizontal cross members 44 (see FIG. 2; one representative member marked), for example in channels. Another means for interconnecting the facing blocks 32 as well as a means for providing reinforcement of the particulate material 38 comprises a fabric, geotextile or geogrid material 46 (see FIGS. 3 and 5) retained by the members 42, for example, and projecting into the particulate material 38.
Numerous permutations and combinations of the described elements are possible. Moreover, numerous alternative configurations of the fasteners or clips 36 are possible. Various alternatives of the anchor blocks 34 may also be used, though it is preferable to use a standard concrete block construction. The following description discusses therefore some of the variations and permutations of the basic construction described in this overview.
FIG. 2 depicts a right angle wall corner which incorporates corner blocks 48 which are alternated in direction at the corners as depicted in FIG. 2. The corner blocks 48 typically have a front face 50 and side face 52 (representative faces marked) and may include one or more vertical openings or throughbores 54 for receipt of pins that fit through vertically adjacent corner blocks 48 so that the corner will remain in substantially fixed alignment. The vertical openings or throughbores 54 are thus positioned so that the corner blocks 48 may be alternated, with the vertical openings 54 aligned at the corner.
Referring to FIG. 5, there is depicted, in a top plan view, the construction of a convex curve. It is necessary or preferred that the anchor blocks 34 associated with layers of facing blocks 32, forming the curve in the wall, be attached to alternating vertical courses distinct from the alternating vertical courses associated with the adjacent angled section of the wall. Thus, the anchor blocks 34, at least in the vicinity of the curve, may overlap as depicted in FIG. 5, thereby enabling the use of anchor blocks 34 with respect to curved or angled sections of a wall.
It should be noted that FIG. 2 depicts a right angle corner, while FIG. 5 depicts a convex curve. Other corners, curves and angles may be formed and the construction is not limited to a right angle corner and a convex curve. Wall sections may be joined at any angle. Intersections may be curved convexly as shown in FIG. 5. Intersections may form straight angles. Wall sections may join at an angle greater or less than 90.degree. or 180.degree. or be concave as depicted in FIG. 6. The arrangement of the anchor blocks 34 in combination with the facing blocks 32 is such that multiple wall sections forming complex walls can be constructed. In all events, the anchor blocks 34 should extend into particulate material 38 without interfering with each other, as in FIGS. 2 and 5, regardless of the curvature or corners formed in the wall by the facing blocks 32.
Block Constructions
FIGS. 7, 8 and 9 illustrate the construction of a preferred embodiment of the facing blocks 32. As in FIGS. 6 and 7, a front face 60 is positioned on a front wall 62. Converging side walls 64 and 66 connect with a back wall 68 so that a top plan view configuration of the facing block 32 is generally that of a trapezoid. The front face 60 may be textured or configured in a number of ways. For example, the front face 60 may be generally planar. The front face 60 may be also in a convex or concave shape. The front face 60 may also have various shapes applied thereto or inserts applied therein.
A vertical throughbore 70 connects a top surface 72 with a bottom surface 74 of the facing block 32. The surfaces 72 and 74 are generally parallel to one another. The back wall 68 may include detents or slots 76 and 78 adjacent to top surface and bottom surface 72 and 74, respectively.
The height of the facing blocks 32 exceeds the height of the anchor blocks by a fraction of an inch. The profile of the front face 60 is generally that of a rectangle. The side walls 64 and 66 converge to enable formation of curved walls such as depicted in FIG. 5. The slots 76 and 78, as will be explained in greater detail below, are for cooperation with the fasteners or clips 36. The slots 76 or 78 are optional features in the facing blocks 32.
As shown in FIGS. 10-12, the anchor blocks 34 may comprise typical drycast, rectangular, concrete blocks. The anchor blocks 34 are generally of a rectangular, parallelpiped shape. Thus an anchor block 34 will include longitudinal side walls 80 and 82 joined together by transverse side walls 84 and 86. End flanges extend off the side walls 84, 86. An internal web or wall 88 connects the longitudinal walls 80 and 82 at their midpoint. Vertical throughbores 90 and 92 are defined by the arrangement of side walls 80, 82, side walls 84, 86 and web walls 88.
In an alternate block 34, the side walls 84 and 86 may include at their midpoints, either at the top or bottom thereof or in both positions, slots or detents 94 and 96 as shown in FIGS. 13-15. The slots 94 and 96 of anchor block 34 coact with fasteners 36 in the same manner as do slots 76 and 78 associated with the facing blocks 32. A side wall 84 or 86 coacts with a back wall 68 of a facing block 32 and is retained therewith by means of the fasteners or clips 36 in slots 76, 78, 94, 96 as discussed below.
The surfaces of walls 68, 84 and 86 preferably define planar contact surfaces so that the blocks 32, 34 will fit snugly against each other. The heights of the facing blocks 32 and alternate anchor blocks 34 of FIGS. 13-15 are preferably equal.
Fasteners
FIGS. 16 through 27 illustrate various types of fasteners which are used to interconnect blocks 32, 34. Referring first to FIG. 16, there is illustrated a clip or fastener 36 which is comprised of a pair of opposed spaced legs 100 and 102 joined by a crown 104. The fastener or clip 36 is typically made of galvanized steel and the legs 100 and 102 are spring biased toward one another by the crown 104. The legs 100 and 102 may fit over adjacent side walls 84 and 86 of adjacent anchor blocks 34. Alternatively the clips 36 fit over an adjacent side wall 84 or 86 of anchor block 34 and back wall 68 of facing block 32 to connect them together as depicted in FIGS. 1-3, 5 and 6. The crown 104 may fit into slots 76 and 94 associated with the facing blocks 32 and alternate anchor blocks 34 when such slots 76, 94 are provided. One or two fasteners 36 may be used for each connection of blocks. That is, the fasteners 36 may connect the bottom and/or top of each pair of joined blocks. Connection at the top is preferred and depicted in FIGS. 1 and 3.
As depicted in FIGS. 17-19, an alternate fastener 36 may also have legs 100, 102 joined by a crown 104. A lower run 106 and 108 of each leg 100 and 102 is upwardly and outwardly curved.
As depicted in FIG. 20, second alternate fasteners or clips 36 may include an upwardly extending pin 110 attached thereto which can coact with a soil reinforcing element such as a geogrid, geotextile, wire mesh or steel strip material 112 as shown in FIGS. 3 and 5 (one representative pin marked). The pin 110 may be hook shaped or otherwise shaped to coact with the geogrid material 112 or any other screening or earth stabilizing material or member. Pin or hook 110 is preferably positioned over the side wall 84 or 86 of anchor block 34, so it will not interfere with the adjacent stacked facing blocks 32.
FIGS. 21 and 22 illustrate another alternative construction for a fastener. Here the fastener 114 comprises a pair of opposed legs 116 and 118 joined by a crown 120. The legs 116 and 118 have an extent or height which is substantially equal to the depth or height of the back wall 68 of the facing block 32 and the side walls 84,86 of the anchor block 34. The legs 116 and 118 are biased toward each other by virtue of the construction of the crown 120. The legs 116 and 118 include inwardly projecting tabs 122 and 124, respectively, which tend to lock adjacent blocks 32 and 34 together by fitting over the walls, e.g. walls 68 and 84.
FIGS. 23 and 24 illustrate yet another construction for a fastener or clip. Here a rod or pin 126 connects spaced plates 128 and 130. The rod or pin 126 may be a nut and bolt fastener which is adjustable to thereby adjust the distance between the plates 128 and 130 and to thereby permit the plates 128 and 130 to be tightened. The pin 126 may fit within slots, such as slots 76 and 94 defined in the facing block 32 and anchor block 34 with the plates 128, 130 fitting against the walls 68, 80. As in FIG. 27, the pin 126 may have plates 128, 130 in the form of washers. Bolted connection may be made by placement through additional holes or slots (not shown) in the walls of the blocks.
FIGS. 25 and 26 illustrate yet another method or construction for a fastener. Here a flexible strap 132 is provided. The strap 132 is positioned around the back wall 68 and side wall 84. The ends of the strap 132 are configured with a buckle or latching mechanism 134 to thereby hold the anchor block 34 and facing block 32 or a pair of anchor blocks 34 together.
Numerous alternatives to the described block construction as well as the fasteners and the manner in which they may be stacked and interconnected are possible. Utilization of geogrid materials and other reinforcing materials to interconnect the facing blocks 32 and anchor blocks 34 may be varied in numerous ways. In all events, the simplicity of the construction is enhanced by the ability to use a simple facing block 32 construction in combination with an anchor block 34 construction of equal simplicity. The anchor block 34 construction is, in fact, of a type already commonly available. The retaining walls of the present invention are especially useful for low height gravity walls, for example walls up to six feet or thereabouts in height. With the present invention it is especially advantageous to construct such walls since they may be constructed manually. Thus, while there has been set forth a preferred embodiment of the invention, it is to be understood that the invention is to be limited by the following claims and their equivalents.
Claims
  • 1. A retaining wall construction comprising, in combination:
  • a plurality of generally modular facing blocks arranged in courses with vertically adjacent blocks laterally overlapping one another, at least in part, to define a mosaic, said blocks each having a generally rectangular front face, a front wall defining the front face, a back wall spaced from the front wall with a hollow throughbore therebetween, and sidewalls joining the back wall to the front wall, said back wall defining a generally planar contact surface;
  • at least one precast, hollow core, generally rectangular parallelpiped, anchor block of the type having side walls defining generally planar contact surfaces with one of said contact surfaces of said anchor block positioned against the contact surface of a back wall of a facing block;
  • a separate fastener element for attaching a side wall of an anchor block to the back wall of a facing block, said fastener element extending from the hollow throughbore of a facing block to the hollow core of an anchor block; and
  • fill material surrounding and filling the hollow anchor blocks and the region adjacent the back surface of the facing blocks.
  • 2. The retaining wall of claim 1 including at least one additional anchor block with its side wall positioned against the side wall of the anchor block fastened to a facing block.
  • 3. The retaining wall of claim 1 including soil reinforcing elements attached to blocks and extending into the fill material.
  • 4. The retaining wall of claim 1 wherein the side walls of the facing block converge together from the front face.
  • 5. The retaining wall of claim 1 further including a notch in the facing block back wall wherein the fastener includes a clip member which fits in the notch of the facing block back as well as inside of the anchor block.
  • 6. The retaining wall of claim 1 including anchor blocks attached to alternate courses of facing blocks.
  • 7. The retaining wall of claim 1 including vertical members extending through the hollow core of vertically adjacent facing blocks.
  • 8. The retaining wall of claim 1 including granular particulate in the hollow core of the vertically adjacent facing blocks.
  • 9. The retaining wall of claim 1 further including horizontal connecting cross members comprising means for interconnecting adjacent facing blocks.
  • 10. The wall of claim 1 wherein the fastener comprises a flexible strap encircling the facing block back wall and anchor block side wall.
  • 11. The wall of claim 1 wherein the fastener comprises a clip member including a crown joining a pair of legs and the legs are positioned to retain the facing block back wall and anchor block side wall therebetween and joined.
  • 12. The wall of claim 1 wherein the fastener comprises a pin having flange members at its opposite ends and wherein the flange members are positioned to retain the facing block back wall and anchor block side wall therebetween and joined.
  • 13. The wall of claim 1 defining a first wall section and further including facing blocks forming a second wall section at an angle with the first wall section and wherein the first wall section includes anchor blocks attached to facing blocks in a course of blocks different then the course of facing blocks to which anchor blocks are attached in the second wall section.
  • 14. The retaining wall of claim 1 wherein the wall includes facing blocks forming a first wall section and facing blocks forming a connected second wall section at an angle to the first wall section.
  • 15. The retaining wall of claim 1 wherein the wall includes facing blocks and anchor blocks of substantially equal height.
  • 16. The retaining wall of claim 1 wherein the facing wall blocks are fabricated from dry cast concrete.
  • 17. The retaining wall of claim 1 wherein the facing wall blocks have converging side walls, a generally flat planar front face, and a vertical hollow throughbore defining the front, back and side walls.
  • 18. The retaining wall of claim 1 wherein the anchor block has a rectangular, parallelpiped shape with at least one throughbore from the top to the bottom surface and a height no greater than the height of the facing blocks.
  • 19. The retaining wall of claim 18 wherein the hollow throughbores of the facing blocks and the throughbores of the anchor blocks are filled with concrete, the retaining wall further comprising a cast in place footing.
  • 20. The retaining wall of claim 18 wherein the concrete is reinforced.
CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation-in-part of application Ser. No. 08/040,904 filed Mar. 31, 1993; design patent application Ser. No. 29/009,442 filed Jun. 4, 1993; design patent application Ser. No. 29/009,214 filed Jun. 7, 1993, now U.S. Pat. No. Des. D345,426; design patent application Ser. No. 29/011,818 filed Aug. 16, 1993; and application Ser. No. 08/108,933 filed Aug. 18, 1993; all of which are currently pending in the U.S. Patent Office.

US Referenced Citations (60)
Number Name Date Kind
126547 Hickcox May 1872
228052 Frost May 1880
D237704 Lane Nov 1975
384541 Palmer Jun 1888
566924 Morrin Sep 1896
654733 Humes Jul 1900
810748 Haller et al. Jan 1906
1092621 Worner Apr 1914
1414444 Straight May 1922
1456498 Binns May 1923
1762343 Munster Jun 1930
1818416 Meara Aug 1931
2235646 Schaffer Mar 1941
2252155 Baldwin Aug 1941
2313363 Schmitt Mar 1943
2882689 Huch et al. Apr 1959
2963828 Belliveau Dec 1960
3036407 Dixon May 1962
3252287 Suzuki May 1966
3274742 Paul, Jr. et al. Sep 1966
3332187 Arcari Jul 1967
3390502 Carroll Jul 1968
3418774 Kocher et al. Dec 1968
3430404 Muse Mar 1969
3557505 Kual Jan 1971
3686873 Vidal Aug 1972
3936987 Calvin Feb 1976
3995434 Kato et al. Dec 1976
3998022 Muse Dec 1976
4016693 Warren Apr 1977
4110949 Cambiuzzi et al. Sep 1978
4116010 Vidal Sep 1978
4177617 DeLuca et al. Dec 1979
4207718 Schaaf et al. Jun 1980
4208850 Collier Jun 1980
4228628 Schlomann Oct 1980
4229123 Heinzmann Oct 1980
4312606 Sarikelle Jan 1982
4324508 Hilfiker et al. Apr 1982
4329089 Hilfiker et al. May 1982
4335549 Dean, Jr. Jun 1982
4449857 Davis May 1984
4454699 Strobl Jun 1984
4470728 Broadbent Sep 1984
4496266 Ruckstuhl Jan 1985
4505621 Hilfiker et al. Mar 1985
4524551 Scheiwiller Jun 1985
4572699 Rinninger Feb 1986
4725170 Davis Feb 1988
4776728 Sprehn Oct 1988
4802318 Snitovski Feb 1989
4802320 Forsberg Feb 1989
4909010 Gravier Mar 1990
4914876 Forsberg Apr 1990
4961673 Pagano et al. Oct 1990
4998397 Orton Mar 1991
5004376 Vidal et al. Apr 1991
5091247 Willibey et al. Feb 1992
5178492 Meheen Jan 1993
5350256 Hammer Sep 1994
Foreign Referenced Citations (35)
Number Date Country
2031077 May 1991 CAX
0079880 May 1983 EPX
0047717 Jun 1983 EPX
0047718 May 1984 EPX
0170113 Feb 1986 EPX
0212357 Mar 1987 EPX
0430890A1 Jun 1991 EPX
0472993 Mar 1992 EPX
2367147 May 0578 FRX
392474 Nov 1908 FRX
1129634 Jan 1957 FRX
1360872 Apr 1963 FRX
2216823 Aug 1974 FRX
7528079 Sep 1975 FRX
2610962 Aug 1988 FRX
2633650 Jan 1990 FRX
2414202 Oct 1975 DEX
2944550 Sep 1981 DEX
3025883 Jan 1982 DEX
3401629A1 Jul 1984 DEX
4103330 Sep 1991 DEX
586016 Sep 1981 JPX
84735 Jun 1920 SEX
205452 Sep 1939 SEX
336 Jan 1871 GBX
14528 Jan 1913 GBX
120872 Nov 1918 GBX
1385207 Feb 1975 GBX
2014222 Nov 1979 GBX
2127872 Apr 1984 GBX
383156103 Nov 1992 GBX
27174 Jan 1930 SUX
894038 Dec 1981 SUX
1090803A May 1984 SUX
8802050 Mar 1988 WOX
Non-Patent Literature Citations (26)
Entry
AASHTO-AGC-ARTBA Joint Committee, Subcommittee On New Highway Materials, Task force 27 Report "In Situ Soil Improvement Techniques" (Undated).
Silifrance Product Information Sheet (Undated).
Besser Co. "The Beauty of Concrete Block" (Undated).
Rockwood Classic Retaining Wall System Product Information Sheet (Undated).
Earthworks.TM. Retaining Wall System Product Information Sheet (Undated).
EarthStone.TM. Erosion Control/Retaining Wall System Product Information Sheet (Undated).
Rockwood Retaining Walls, Inc. Product Information Sheet (Undated).
RISI Stone Retaining Wall Systems "Preserving Our Environment" Information Brochure (1976).
Reinforced Earth Co..RTM. "Design of Live Storage Structures Using Reinforced Earth.RTM." (1983).
Reinforced Earth Co..RTM. "Industrial Applications of Reinforced Earth.RTM. Structures" (1988).
Versa-Lok.RTM. Retaining Wall Systems Information Brochure (1989).
Structural Block Systems, Inc. "Introducing Radial Block" (1990).
Allan Block.TM. Retaining Walls "A Mortarless, Stackable Concrete Block Retaining Wall System" (1990).
Interim, Highway Bridges, Division I--Design, 5.8.7.2 "Polymeric Reinforcements" (1991).
Westblock Products, Inc. "GravityStone.TM." (1992).
Genesis.TM. Highway Wall System (1992).
Hunziker "Cobra" (1992).
Keystone.TM. Retaining Wall Systems "Standard Unit" (1993).
Keystone.TM. Retaining Wall Systems "Mini and Cap Unit" (1993).
Publication "Modular Concrete Block" (1984).
Publication "Paving Stone: A New Look with Old World Charm" (1984).
Publication "Methods of Making Split Corners" (1985).
Hollow Building Assoc. Handbook "Standard Load-Bearing Wall Tile" (1924).
Concrete Masonry Pictorial, vol. 33, No. 3, .COPYRGT.1977 p. 5.
The Contractor, vol. 2 No. 9, Oct. 1987, pp. 13-16.
Tensar Concrete GeoWall Brochure (1986).
Continuation in Parts (1)
Number Date Country
Parent 40904 Mar 1993