US20100303555A1

US20100303555A1 - Concrete block for wall, walls having such blocks, and methods

Info

Publication number: US20100303555A1
Application number: US12/476,820
Authority: US
Inventors: Allan John Herse; Joseph P. Powers
Original assignee: Anchor Wall Systems Inc
Current assignee: Anchor Wall Systems Inc
Priority date: 2009-06-02
Filing date: 2009-06-02
Publication date: 2010-12-02
Also published as: AU2010201838A1; NZ585350A; EP2261435A2; CA2703377A1; MX2010006059A

Abstract

A concrete retaining wall block includes insets along the sides and in the rear and a locator protrusion on one of the top or bottom surfaces. The block has a depth that is less than the height and less than one-half of the width of the front surface. A volume is defined behind the front surface of the block. The volume is shaped to receive pourable concrete when a plurality of the blocks are stacked to form a wall in a manner that locks the blocks to concrete behind the blocks when the concrete cures. In preferred embodiments, the concrete is no-fines concrete. Retaining walls may be constructed from these blocks.

Description

TECHNICAL FIELD

This disclosure relates generally to concrete blocks and walls made with such concrete blocks. More specifically, this disclosure relates to concrete blocks that can be used to form walls with the use of no-fines concrete.

BACKGROUND

Concrete blocks have been used for the construction of walls, such as retaining walls. In some systems, the walls are constructed in courses, and then held in place through the use of structure such as deadheads, tie backs, a matrix web, or geo grid.
There is a need for a concrete block that is stackable to form walls of high structural integrity without the use of complex connection systems, without the need for securing mechanisms such as tie back rods, without the need for matrix webs or geo grids, and which is convenient and easy to handle.

SUMMARY OF THE DISCLOSURE

In accordance with a first aspect, a block is provided including a front surface, a back surface, a top surface, a bottom surface, and first and second sides. The first side has a first inset, with the first inset extending from the block top surface to the block bottom surface. The second side has a second inset. The second inset extends from the block top surface to the block bottom surface. A locator protrusion is provided. The locator protrusion can be on one of the top or bottom surfaces. The locator protrusion is configured to mate with an inset of one or more adjacently positioned blocks. The locator protrusion and the first and second insets have sizes and shapes adapted to permit relative rotation of the locator protrusion and the respective inset with which the locator protrusion is mated to enable a construction of serpentine walls from a plurality of the blocks. The block defines a height between the top surface and the bottom surface, as well as a depth between the front surface and the back surface. The depth is less than the height and less than one-half of the width of the front surface. A volume is defined behind the front surface. The volume is shaped to receive pourable concrete when a plurality of the blocks are stacked to form a wall in a matter that locks the blocks to concrete behind the blocks when the concrete cures.
In another aspect, a retaining wall is provided. The retaining wall is constructed of a plurality of the blocks, as characterized above, assembled in courses. The retaining wall includes cured, no-fines concrete generally filling the volume behind the front surfaces of the blocks and extending into the area behind the wall to stabilize the retaining wall.
In another aspect, a retaining wall block is provided including a front surface, a back surface, a top surface, a bottom surface, a first side, and a second side. The top surface has at least a contact portion thereof that is generally horizontal and generally planar, when the block is oriented in a position with the top surface facing up. The bottom surface has at least a contact portion thereof that is generally horizontal and generally planar and that is configured and adapted to rest upon the contact portion of the top surface of a like block when a plurality of like blocks are stacked in ascending courses. The block has a first inset in the first side and a second inset in the second side. Each of the first and second insets have inset walls. The inset walls include a front wall, a back wall, and an interconnecting wall connecting the front and back walls. The front wall and back wall each extend inwardly towards the opposite side. The block defines a height between the top surface and the bottom surface. The block defines a depth between the front surface and the back surface, with the depth being less than the height and less than one-half of the width of the front surface. One or more locator protrusions are integrally formed on one of the top or bottom surface. The front, back, and interconnecting walls each extend from a surface that is generally co-planar with the generally horizontal and generally planar contact portion of the surface opposite the surface on which the one or more locator protrusions are formed. Each locator protrusion is constructed and arranged to interact with at least one of the inset walls of an inset on a block in an adjacent course of blocks when a plurality of like blocks are stacked in ascending courses to form a retaining wall so that the insets and locator protrusions of adjacent blocks in adjacent courses contact each other in a shear-resisting position in which interference between the locator protrusions and inset walls resist a tendency of a block in the upper course to slide forward in response to anticipate forces exerted on the block by retained earth. The locator protrusions and insets are sized and shaped to permit relative rotation of the insets and locator protrusions to facilitate construction of serpentine walls while maintaining the shear-resisting position. A volume is defined behind the front surface of the block. The volume is shaped to receive pourable concrete when a plurality of the blocks are stacked to form a wall in a manner that locks the blocks to concrete behind the blocks when the concrete cures.
In another aspect, a retaining wall is provided constructed of a plurality of the blocks as characterized in the proceeding paragraph. The blocks are assembled in courses and include cured no-fines concrete generally filling the volume behind the front surfaces of the blocks and extending into the volume behind the wall to stabilize the retaining wall.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of a concrete block, constructed in accordance with principles of this disclosure;

FIG. 2 is an enlarged top plan view of a locator protrusion that is a part of the block of FIG. 1, the enlargement being taken from the block shown in FIG. 4;

FIG. 3 is a front elevational view of the block of FIG. 1;

FIG. 4 is a bottom plan view of the block of FIG. 1;

FIG. 5 is a top plan view of the block of FIG. 1;

FIG. 6 is a schematic depiction of the cross-sectional view for volume that is for receiving pourable concrete when a plurality of the blocks are stacked to form a wall;

FIG. 7 is a front elevational view of one embodiment of a wall constructed from a plurality of the blocks of FIG. 1;

FIG. 8 is a top plan view of another embodiment of a wall constructed from a plurality of the blocks of FIG. 1;

FIG. 8A is an enlarged view of a portion of the wall shown in FIG. 8;

FIG. 8B is a top plan view of an enlarged portion of the wall of FIG. 8;

FIG. 9 is a schematic, cross-sectional view of a wall constructed from a plurality of the blocks of FIG. 1 and showing no fines concrete, or stabilized aggregate, used to help hold the wall; and

FIG. 10 is a schematic, cross-sectional view showing one course of the wall of FIG. 9, and showing the no fines concrete or stabilized aggregate in use to stabilize the wall.

DETAILED DESCRIPTION

A. Example Block Construction, FIGS. 1-6
Turning to the figures, wherein like parts are designated with like numerals throughout several views, there is shown a composite block in FIG. 1 at reference numeral 20. The block is preferably made from concrete, for example, dry cast concrete. In some embodiments, the block 20 can be made from wet cast concrete.
In FIG. 1, the block 20 is depicted in perspective view in the orientation that it preferably would be placed when in use in constructing a wall. In the embodiment shown, the block 20 includes a front surface 22. In this embodiment, the front surface 22 is depicted as being flat and planar. In normal use, the front surface 22 will be the surface that forms the most visible portion of a retaining wall. The front surface 22 can be textured, roughened, or molded to have a decorative eye-catching ornamental appearance in three dimensions.
Still in reference to FIG. 1, the block 20 has a back surface 24, which is opposite of the front surface 22. In the embodiment shown, the back surface 24 defines first and second legs 26, 28. The first and second legs 26, 28 define a back surface pocket 30 therebetween.
The back surface pocket 30 extends between the first leg 26 and second leg 28 and, in this embodiment, extends the entire height of the block 20 from a block top surface 32 to a block bottom surface 34. The back surface pocket 30 forms a portion 38 of a receiving volume 36 (FIG. 6) that is defined behind the front surface 22. The receiving volume 36, including the back surface volume portion 38 is shaped and configured to receive pourable concrete when a plurality of the blocks 20 are stacked to form a wall. This is discussed further below.
In the embodiment shown, the back surface pocket 30 has first and second opposed walls 40, 41 connected by an extending wall 42 (see FIG. 5). The first wall 40 is formed as an inside surface 44 of the first leg 26. The first wall 40 is angled inwardly as it extends from the extending wall 42 until reaching the end wall 46 of the first leg 26.
The second wall 41, in this embodiment, is constructed as a mirror image of the first wall 40. As such, the second wall 41 is formed along an inside surface 48 of the second leg 28. The second wall 41 is angled generally inwardly from the extending wall 42 to an end wall 50 of the second leg 28.
In the embodiment shown, the extending wall 42 has a length between the first and second walls 40, 41 that is more than twice the length of one of the end walls 46, 50. In one usable embodiment, the length of the extending wall 42 is at least 180 mm, for example, 190-210 mm. The length of the extending wall 42, in the example embodiment shown, is at least 6 times the length of one of the first and second walls 40, 41. In one example, the first and second walls have a length of at least 20 mm, for example, 25-40 mm.
In the embodiment shown, the extending wall 42 is generally straight, flat, and planar. This portion of the block 20 is usually not visible in use in a retaining wall and need not be attractive or eye catching. It should be constructed to allow for receipt of pourable concrete in order to stabilize a constructed wall.
In one example embodiment, the length of each of the end walls 46, 50 are at least 75 mm, for example 80-100 mm.
Again, in reference to FIG. 1, the block 20 includes first and second opposite sides 56, 58. In the embodiment shown, the first side 56 has a first inset 60. The first inset 60 extends the entire height of the block 20 from the top surface 32 to the bottom surface 34.
In the embodiment shown, the first side 56 includes a first side wall portion 62 extending from the front surface 22. The first side wall portion 62 is angled or tapered to form a converging side 64 to converge from the front surface 22 to the back surface 24. This converging side 64 allows wall constructed with the blocks 20 to be formed with curves and/or in serpentine configurations.
In the embodiment shown, the first inset 60 is defined by inset walls including a first inset front inset wall 66, a first inset back inset wall 68, and a first inset interconnecting wall 70. The front inset wall 66 extends from the first side wall converging portion 62 and is angled generally between 80-120 degrees relative thereto. The front inset wall 66 is flat, planar, and generally parallel to the front surface 22.
The back inset wall 68 is angled outwardly in a direction from the interconnecting wall 70 toward the end wall 46 of the first leg 26. A radius portion 72 joins the back inset wall 68 with the end wall 46 of the first leg 26. This angle is generally at least about 55 degrees, for example about 60-75 degrees, with one useful angle being about 66 degrees.
In the embodiment shown, the interconnecting wall 70 joins the front inset wall 66 and the back inset wall 68 at a generally radiused portion 74.
The first inset 60 forms a first inset volume portion 76 (FIG. 6) that is part of the receiving volume 36 for receiving pourable concrete when a plurality of the blocks are stacked to form a wall in a manner that locks the blocks to concrete behind the blocks when the concrete cures.
In the embodiment shown, the second side 58 is formed as a mirror-image of the first side 56. As such, the second side 58 includes a second inset 78. The second side 58 includes a second side wall portion 80 that extends from the front surface 22. The second side wall portion 80 is angled such that it forms a converging side 82 that converges in a direction from the front surface 22 toward the back surface 24. The converging sides 64, 82, are angled and converge as they extend toward the back surface of the block.
The second inset 78 is configured like the first inset 60. As such, it includes a second inset front inset wall 86, a second inset back inset wall 88, and a second inset interconnecting wall 90. The front inset wall 86 is angled relative to the second side wall portion 80 at an angle between 80 degrees-120 degrees. In general, the front inset wall 86 is flat, planar, and generally parallel to the front surface 22.
The second inset back inset wall 88 extends from the interconnecting wall 90 to the end wall 50 of the second leg 28. A radiused portion 92 joins the end wall 50 with the second inset back inset wall 88. The back inset wall 88 is angled relative to the end wall 50 at an angle of at least about 55 degrees, for example about 60-75 degrees, with one useful angle being about 66 degrees.
The interconnecting wall 90 forms a radiused portion 94 joining the front inset wall 86 and back inset wall 88.
The second inset 78 forms a second inset volume portion 96 (FIG. 6) that is part of the receiving volume 36 that is shaped to receive pourable concrete when a plurality of the blocks are 20 are stacked to form a wall in a manner that locks the blocks 20 to concrete behind the blocks when the concrete cures.
The first and second insets 60, 78 are constructed and arranged to help locate the block 20 relative to other blocks 20, when arranging the blocks 20 into a usable retaining wall. In particular, the first and second insets 60, 78 of a block interact with the locator structure of a like block 20 in the course of blocks above it.
In the example embodiment illustrated, the locator structure on the block 20 is embodied as a locator protrusion 100. The locator protrusion 100 may be on at least one of the top surface 32 or bottom surface 34 of the block 20. As can be seen by comparing FIGS. 1, 3, 4, and 5, the top surface 32 and the bottom surface 34 are flat or planar, other than the extending protrusion 100. The top and bottom surfaces 32, 34 are on opposite surfaces of the block 20, and the front surface 22, back surface 24, first side 56 and second side 58 extend between the top surface 32 and bottom surface 34.
The locator protrusion 100 is used if a block is configured to mate with an inset 60, 78 of one or more blocks 20 in the course of blocks below it. The locator protrusion 100 and the first and second inset 60, 78 have relative sizes and shapes adapted to permit relative movement, such as rotation, of the locator protrusion and the respective inset 60, 78 with which the locator protrusion 100 is made to enable a construction of serpentine walls from a plurality of the blocks 20.
In the embodiment shown, the locator protrusion 100 is a single locator protrusion 100 on the block 20. The single locator protrusion 100, in this embodiment, is shown on the bottom surface 34 and between the first and second insets 60, 78. In FIG. 4, it can be seen how the protrusion 100 is centered between the first and second insets 60, 78.
In the embodiment shown, the protrusion 100 has a symmetrical shape along a central access 102 (FIG. 2). In general, in the embodiment shown, the protrusion 100 has the shape of a kidney, or of a race track with upturned rounded end sections or curved portions 104, 105. This embodiment shows the protrusion 100 as having a pair of opposite parallel straight sections 106, 107 extending between the upturned rounded sections 104, 105.
The protrusion 100 is sized appropriately to mate with the insets 60, 78. In the embodiment shown, the protrusion 100 has an overall width between end section 104 and end section 105 of at least 65 mm, for example, 70-80 mm. The protrusion 100, in the embodiment shown, has an overall length between an uppermost part of the end section 104 or 105 and straight section 107 of at least 20 mm, for example, 25-35 mm. The protrusion 100, in the embodiment shown, has an overall height, (as can be seen in FIG. 3 as the dimension extending from the bottom surface 34) of at least 5 mm, for example 8-15 mm.
The locator protrusion 100 is constructed and arranged to interact with at least one of the inset walls of the first and second insets 60, 78 on a block 20 in an adjacent course of blocks when a plurality of like blocks are stacked in ascending courses to form a retaining wall. This is described further in section B, below. When arranged in this way, the inset 60, 78 and locator protrusions 100 contact each other in a shear-resisting position in which interference between the locator protrusions 100 and inset walls (66, 68, 70, 86, 88, 90) resist a tendency of a block 20 in an upper course to slide forward in response to anticipated forces exerted on the block 20 by retained earth.
As can be appreciated by reviewing FIGS. 1, 4, and 5, the top surface 32 of the block 20 has at least a contact portion 52 that is generally horizontal and generally planar, when the block 20 is oriented in a position with the top surface 32 facing up. Similarly, the bottom surface 34 has a contact portion 54 that is generally horizontal and generally planar and that is configured and adapted to rest upon the contact portion 52 of the top surface 32 of a like block 20, when a plurality of the like blocks 20 are stacked in ascending courses. The first and second insets 60, 78 have their respective inset walls 66, 68, 70, 86, 88, 90 each extending from a surface that is generally coplanar with the generally horizontal and generally planar contact portion 52 or 54 of the surface opposite the surface on which the locator protrusion 100 is formed. In the embodiment shown, these inset walls for first and second inset 60, 78 each extend from and between the generally horizontal and generally planar contact portions 52 and 54 of the top surface 32 and bottom surface 34.
In this embodiment, the block 20 is designed as a substantially balanced block 20, in that a plane parallel to the front surface 22 that is half way between the front surface 22 and back surface 24 has about 49% of the weight in front of the plane (between the plane and the front surface 22) and about 51% of the weight to the rear of the plane (between the plane and the back surface 24). In FIG. 5, a center of gravity is shown at 110. As can be seen, the protrusion 100 is located with the straight section 106 aligned with a plane passing through the center of gravity 110, and a remaining portion of the protrusion 100 located between the plane passing through the center of gravity 110 and the back surface pocket 30. The distance 112 between the front surface 22 and the plane passing through the center of gravity 110, (which is also aligned with the straight section 106 of the protrusion 100) is between 38 percent and 50 percent, for example 40-45 percent of the distance 114 that corresponds to the depth of the block 20. The depth of the block 20 is distance 114 between the front surface 22 and the back surface 24 including the end walls 46, 50 of the first and second legs 26, 28. In one embodiment, the distance 112 is 62-64 mm, while the depth 114 is 149-151 mm.
In FIG. 3, the center of gravity 110 can be seen schematically from the front elevational view. A plane passing through the center of gravity 110 is roughly half way between the top surface 32 and bottom surface 34 in that distance 116 is between 49 and 51 percent of the distance 118 between the top surface 32 and bottom surface 34 of the block 20. The distance 118 also corresponds to the height of the block 20. In one embodiment, the distance 116 is 99-101 mm, while the height 118 is 199-201 mm.
A plane passing through the center of gravity 110 between the first side 56 and second side 58 is about half way between the first side 56 and second side 58, in this embodiment. As such, in FIG. 3, the distance 120 is about 49-51 percent of the distance 122 between the first side 56 and second side 58. The distance 122 also corresponds to a width of the block 20. In one embodiment, the distance 120 is about 224-226 mm, while the distance 122 is about 449-451 mm.
In the embodiment shown, the depth 114 is less than the height 118 and is less than one-half of the width 122 of the front surface 22.
B. Wall Constructions and Methods Utilizing Blocks 20
Turning now to FIGS. 7-8B, the block 20 can be used to form retaining walls, such as straight wall 126 (FIG. 7) or curved or serpentine walls, such as wall 128 (FIG. 8).
In FIG. 7, the wall 126 includes a plurality of courses 130, 131, 132, which are shown as rows of block 20. This embodiment includes 3 courses, 130, 131, 132, and other embodiments may include more or fewer courses.
Generally, construction of wall 126 may be undertaken by first defining a trench area beneath the plane of the ground in which to deposit the first course of blocks 20. Once defined, the trench is partially refilled with a compactable base of sand and gravel and tamped or flattened. The first course of blocks 20 is then laid into the trench. Successive courses of blocks 20 are then stacked on top of proceeding courses. In stacking the blocks 20 onto a preceding course, the locator protrusion 100 is used so that the course of blocks 20 being laid are located in a shear-resisting position relative to the blocks in the preceding course. The result is that the blocks 20 in each ascending course are set back from the blocks in the adjacent course below it. For example, the blocks 20 in course 131 are set back from the blocks in the course 130. The blocks in the course 132 are set back from the blocks in the course 131. The locator protrusions 100 are positioned on the course above, such that one block 20 is being positioned over two adjacent blocks 20. When forming a straight wall, such as wall 126, the curved sections 104, 105 of the protrusion 100 engages or abuts the front inset wall 66 or 86 of the respective first or second inset 60, 78 of the two blocks 20 in the course below the block 20 being laid.
The wall 128 is configured in a curved or serpentine pattern, which can form both concave sections (FIG. 8A) and convex sections (FIG. 8B). In FIG. 8A, it can be seen how the blocks 20 are positioned adjacent to each other so that the front surfaces 22 appear to be continuous with no gaps in between. The adjacent blocks 20 are turned relative to each other to form concave section such that there is a wider gap between adjacent converging side 64 and 82 than when the blocks 20 are arranged in a straight pattern next to each other. In FIG. 8A, reference numeral 100′ shows where the protrusion for the next course to be laid would be located. The protrusion shown at 100″ is the protrusion for block 20″, if one could see through the top of block 20″ and see protrusion 100″ projecting from the bottom surface 34. As can be seen in FIG. 8A, the curved sections 104, 105 of the protrusion 100′ engage against the front inset walls 86, 66 of the two blocks in the course below the block having protrusion 100′.
In FIG. 8B, a convex section of the wall 128 is illustrated. In FIG. 8B, it can be seen how the adjacent converging sides 64, 82 have a smaller gap in between them than when the wall is formed in a concave section, as in FIG. 8A. The gap between converging sides 64, 82 in FIG. 8B is also smaller than when the blocks are arranged side by side in a straight formation. In FIG. 8B, the protrusion 100′ is shown as it would be the protrusion from the block in the next ascending course. The protrusion 100′ has curved sections 104, 105 that engage the respective front walls 86, 66 of the second inset 78 and first inset 60, respectively.
When constructing a retaining wall, after some of the courses are laid up, pourable concrete is poured into the volume 36 at the back of the blocks 20 and in the area behind the wall. When this concrete cures, the wall is stabilized. This concrete is used instead of geo grid, which requires much more space behind the walls to be excavated, or tie back rods.
One particularly useful type of concrete that is used is stabilized aggregate, also referred to herein as “no fines concrete.” No fines concrete means there is very little, if any, fine particles that are used in the concrete mix. One useful mixture for stabilized aggregate or no fines concrete includes: aggregate having sizes of stone, such as crushed stone, that is not less than 10 mm, typically about 19 mm; a compressive strength of not less than 10 MPa; an appropriate amount of cement such that the ratio of aggregate to cement is between 6:1 to 7:1; and for every 50 kg bag of cement there are 20 liters of water. Because no fines are used in this mixture, when the concrete cures, the concrete is relatively porous to permit water to drain through the cured concrete to a drain tile at the base of the wall, which carries the water away.
While the strength of the example concrete mixture mentioned above is specified as being not less than 10 MPa, strength is difficult to measure for concrete made from stabilized aggregate, or no fines. This is because the concrete is so porous and open that a cylinder compressive strength test is difficult to conduct. Thus, the strength of the concrete mixture is an estimate.
No fines concrete walls have advantages. In no fines concrete walls, the block 20 can be used mainly as the face of the wall and a form for receiving the concrete, and hence, reduces cost with improved performance features.
FIGS. 9 and 10 show schematic, cross-sectional views of a wall 150 made up of blocks 20 and stabilized aggregate, or no fines concrete 152. In general, the depth of the block 20 plus the depth of the stabilized aggregate material 152 is 0.3 to 0.4 of the overall height of the wall 150. For example, if a 6-foot high wall is built, the depth of the stabilized aggregate material 152 plus the block 20 should be about 1.8-2.4 feet deep. In typical systems in which the depth of the block 20 is about 6 inches, the stabilized aggregate mass will be about 16 to 23 inches deep.
In FIG. 9, it can be seen how the initial course 20 of the wall 150 is placed within the earth 154 at course 156. In this embodiment, a drain tile 158 is included in order to help drain moisture through the stabilized aggregate 152 and out through the first course 160 that is above the earth 154. In general, in this embodiment, for every 2-3 courses of blocks 20, a section of stabilized aggregate 152 is poured behind the blocks 20, which fills volume 36, and then cures and stabilizes the wall 150. In FIG. 9, there are three sections stabilized aggregate 152 that have been poured in place to lie between the blocks 20 and earth 154. In this embodiment, there is also a layer of filter fabric 162 between the top course 164 and the next adjacent lower course 166. The filter fabric 162 can be used at this location (at or near the top of the wall 150), to reduce the amount of soil that would drain down into the stabilized aggregate 152. Covering the top course 164 can be a decorative top, cap, or half of a block 20 and a layer of low-permeability soil 170.
In FIG. 9, the blocks 20 create the front face of the wall and a form for the concrete while the stabilized aggregate 152 provides the structural stability. Because there are no fine particulates included in the concrete mixture, rainwater or other moisture is allowed to flow through the stabilized aggregate 152 and then drain through the drain tile 158.
FIG. 10 shows a horizontal cross-sectional view of the wall 150, but shows only a single course. As can be seen in FIG. 10, the stabilized aggregate 152 fills the volume 36 between adjacent blocks 20.
The above discussion, examples, and embodiments illustrate inventive principles. Many variations can be made.

Claims

1. A block comprising:

a front surface, a back surface, a top surface and bottom surface, and first and second sides; the first side having a first inset, the first inset extending from the block top surface to the block bottom surface; the second side having a second inset, the second inset extending from the block top surface to said block bottom surface;

a locator protrusion on one of the top or bottom surfaces, the locator protrusion being configured to mate with an inset of one or more adjacently positioned blocks;

the locator protrusion and the first and second insets having relative sizes and shapes adapted to permit relative rotation of the locator protrusion and the respective inset with which the locator protrusion is mated to enable a construction of serpentine walls from a plurality of the blocks;

a height between the top surface and bottom surface;

a depth between the front surface and back surface; the depth being less than the height and less than one-half of the width of the front surface;

a volume defined behind the front surface; the volume being shaped to receive pourable concrete when a plurality of the blocks are stacked to form a wall in a manner that locks the blocks to concrete behind the blocks when the concrete cures.

2. The block of claim 1 wherein each locator protrusion is formed on the block body in such a location relative to the insets that, when a plurality of like blocks are stacked in ascending courses, and the locator protrusions and insets are positioned in a shear-resisting position, the blocks in each ascending course are set back from the blocks in the adjacent course below.

3. The block of claim 1 wherein:

the front surface of the block is substantially planar;

each of the first and second insets have inset walls, the inset walls including a front wall, a back wall, and an interconnecting wall connecting the front and back walls, the front wall and back wall each extending inwardly towards the opposite side;

and the front walls of the insets are substantially parallel to the front surface.

4. The block of claim 1 wherein the locator protrusion is a single locator protrusion on the block; the single locator protrusion extending along the block bottom surface between the first and second insets.

5. The block of claim 4 wherein the locator protrusion includes a curved portion that is configured to contact the front wall of an inset in a shear resisting position.

6. The block of claim 1 wherein the locator protrusion comprises first and second curved end sections between which is positioned a joining section.

7. The block of claim 1 wherein the first side includes a first converging portion and the second side includes a second converging portion that is opposed to the first converging portion, and the opposed converging portions converge towards each other as they extend from the front surface toward the back surface of the block.

8. The block of claim 1 wherein the back surface includes first and second legs; the first and second legs defining a pocket therebetween; the pocket being at least a portion of the volume shaped to receive pourable concrete.

9. A retaining wall constructed of a plurality of the blocks of claim 2 assembled in courses comprising:

cured no fines concrete generally filling the volume behind the front surfaces of the blocks and extending into the area behind the wall to stabilize the retaining wall.

10. A retaining wall block comprising:

a front surface;

a back surface;

a top surface having at least a contact portion thereof that is generally horizontal and generally planar, when the block is oriented in a position with the top surface facing up;

a bottom surface having at least a contact portion thereof that is generally horizontal and generally planar and that is configured and adapted to rest upon the contact portion of the top surface of a like block when a plurality of like blocks are stacked in ascending courses;

a first side;

a second side;

the block having a first inset in the first side and a second inset in the second side, each of the first and second insets having inset walls, the inset walls including a front wall, a back wall, and an interconnecting wall connecting the front and back walls, the front wall and back wall each extending inwardly towards the opposite side;

a height between the top surface and bottom surface;

one or more locator protrusions integrally formed on one of the top or bottom surface;

said front, back, and interconnecting walls each extending from the generally horizontal and generally planar contact portion of the surface opposite the surface on which the one or more locator protrusions are formed,

wherein each locator protrusion is constructed and arranged to interact with at least one of the inset walls of an inset on a block in an adjacent course of blocks when a plurality of like blocks are stacked in ascending courses to form a retaining wall so that the insets and locator protrusions of adjacent blocks in adjacent courses contact each other in a shear-resisting position in which interference between the locator protrusions and inset walls resist a tendency of a block in the upper course to slide forward in response to anticipated forces exerted on the block by retained earth;

the locator protrusions and insets are sized and shaped to permit relative rotation of the insets and locator protrusions to facilitate construction of serpentine walls while maintaining the shear-resisting position,

11. The block of claim 10 wherein each locator protrusion is formed on the block body in such a location relative to the insets that, when a plurality of like blocks are stacked in ascending courses, and the protrusions and insets are in the shear-resisting position, the blocks in each ascending course are set back from the blocks in the adjacent course below.

12. The block of claim 10 wherein the front surface of the block is substantially planar and said front walls of the insets are substantially parallel to the front surface.

13. The block of claim 10 wherein, for each inset, the height of the front, back and interconnecting walls is generally the same.

14. The block of claim 10 wherein the locator protrusion is a single locator protrusion on the block; the single locator protrusion extending along the block bottom surface between the first and second insets.

15. The block of claim 14 wherein the locator protrusion includes a curved portion that is configured to contact the front wall of an inset in the shear resisting position.

16. The block of claim 10 wherein the distance between said generally horizontal and generally planar portions of said top surface and said bottom surface is substantially equal to the height of said front surface.

17. The block of claim 10 wherein the locator protrusion comprises first and second curved end sections between which is positioned a joining section.

18. The block of claim 10 wherein the first side edge includes a first converging portion and the second side edge includes a second converging portion that is opposed to the first converging portion, and the opposed converging portions converge towards each other as they extend from the front surface toward the back surface of the block.

19. The block of claim 10 wherein the back surface includes first and second legs; the first and second legs defining a pocket therebetween; the pocket being at least a portion of the volume shaped to receive pourable concrete

20. A retaining wall constructed of a plurality of the blocks of claim 11 assembled in courses comprising:

cured no fines concrete generally filling the volume behind the front surfaces of the blocks and extending into the volume behind the wall to stabilize the retaining wall.