BACKGROUND OF THE INVENTION

1. Field of the invention:

The present invention relates to a building block comprising spaced apart inner and outer walls made of hard moldable material, and interconnected through tie members.

2. Brief description of the prior art:

Many building blocks of the above type have been proposed in the prior art. Such building blocks usually comprise outer and inner concrete walls which are spaced apart from each other but interconnected through at least two tie members. Examples are illustrated and described in U.S. patent No. 783,452 (Morenus) issued on February 28, 1905, in U.S. patent No. 1,448,648 granted to H. ilkins on March 13, 1923, in U.S. patent No. 1,778,881 (Alford) granted on October 21, 1930, and in U.S. patent No. 4,177,617 issued on December 11, 1979, in the name of DeLuca et al.

The building blocks described in the above prior art patents present a common major drawback.

After a wall structure has been erected, these blocks do not provide for easy nailing and/or screwing of the interior finishing materials.

To overcome this drawback, U.S. patent No. 5,074,088 (Bergeron et al.) issued on December 24, 1991 proposes a building block comprising inner and outer walls made of concrete and interconnected through elongate tie members having first and second ends respectively embedded in the concrete of the inner and outer walls. A body in which nails and/or screws can be easily driven is fastened to the first end of the tie member and embedded in the concrete of the inner wall with a surface thereof exposed on the outer side of the inner wall to enable nailing and/or screwing through that body.

A disadvantage of the building block of U.S. patent No. 5,074,088 is that it requires a complex molding process; two different elements, the tie member and the nailing/screwing body have to be assembled, mounted and held in the mold, and automatically supplied to the block molding station.

OBJECTS OF THE INVENTION

An object of the present invention is therefore to provide a building block in which the tie member and nailing/screwing body are incorporated into a single element.

Another object of the invention is a brick-patterned building block in which the simulated bricks can be longitudinally offset with respect to each other in the successive rows.

SUMMARY OF THE INVENTION

In accordance with the present invention, ^' there is provided a building block comprising: first and second spaced apart walls of which at least the second wall is made of hard moldable material, this second wall comprising an outer face; and at least one tie member for interconnecting the first and second walls, this tie member having a first end fixedly secured to the first wall and a second hollow end section embedded in the hard moldable material of the second wall and formed with a distal end wall portion exposed on the outer face of the second wall whereby a fastener can be driven through the exposed distal end wall portion to thereby fasten building material on the outer face of the second wall.

The hollow end section enables fabrication of a one piece tie member enabling screwing of building material to the outer surface of the inner wall.

In accordance with a preferred embodiment of the building block, the hollow end section of the tie member comprises a proximate end wall portion exposed on the inner face of the second wall.

The present invention also relates to a kit of building blocks for erecting a wall structure

by superposing many rows of said blocks, wherein each building block comprises inner and outer spaced apart walls of which at least the outer wall has an outer brick-patterned face, and at least one tie member for interconnecting the inner and outer spaced apart walls, this tie member having a first end fixedly secured to the outer wall and a second end fixedly secured to the inner wall. According to the invention, the outer brick-patterned face simulates a single row of n bricks, n being an integer greater than 1, whereby longitudinal offset of the building blocks in successive rows of the wall structure will also offset the simulated bricks of the successive rows.

In accordance with a preferred embodiment, the kit further comprises corner blocks each including (a) inner and outer spaced apart right angle walls of which at least the right angle outer wall has an outer brick-patterned face, and (b) at least one tie member having a first end fixedly secured to the outer right angle wall and a second end fixedly secured to the inner right angle wall, for thereby interconnecting the inner and outer spaced apart right angle walls. The outer brick-patterned face of the right angle outer wall defines an edge dividing the outer brick- patterned face into first and second brick-patterned face sections, the first brick-patterned face section simulating a single row of a number m of bricks, m being an integer, and the second brick-patterned face section simulating a single row of a number p 1/2 of bricks, p being an integer. Preferably, the kit includes first and second corner blocks and the first

and second brick-patterned face sections have respective positions in the first corner blocks, these respective positions of the first and second brick- patterned face sections being reversed in the second corner blocks. At each corner of the wall structure, the first and second corner blocks alternate in the successive rows of building blocks to thereby automatically offsetting the simulated bricks of these successive rows by half the brick length.

According to a further preferred embodiment of the kit of the invention, the building blocks comprises tongue and groove joints to be assembled together into successive rows and form the wall structure. The outer wall of each building block comprises a top horizontal and longitudinal tongue and a vertical end tongue forming together a continuous angular tongue, and the outer wall comprises, on opposite sides of the top tongue, a first inner shoulder and a first outer shoulder offset downwardly with respect to the first inner shoulder to simulate on the outer brick-patterned face a horizontal brick joint. The outer wall also comprises, on opposite sides of the vertical tongue, a second inner shoulder and a second outer shoulder offset toward the center of the outer wall with respect to the second inner shoulder to simulate on the outer brick-patterned face a vertical brick joint.

Advantageously, to form the tongue and groove joints, each inner and outer wall of the building blocks comprises an inner layer of hard moldable material, an intermediate layer of hard

moldable material and an outer layer of hard moldable material, the intermediate layer being offset horizontally and vertically with respect to the inner and outer layers to form the tongues and grooves of the joints.

The objects, advantages and other features of the present invention will become more apparent upon reading of the following non restrictive description of preferred embodiments thereof, given by way of example only with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the appended drawings:

Figure 1 is a perspective view of a building block in accordance with the present invention, for erecting the foundations of a building, this block comprising an outer wall and an inner wall interconnected by means of tie members;

Figure 2 is a bottom view of the building block of Figure 1;

Figure 3 is an elevational end view of the building block of Figure 1;

Figure 4 is an elevational view of the outer face of the inner wall of the building block of Figure 1;

Figure 5 is an elevational view of the outer face of the outer wall of the building block of Figure 1;

Figure 6 is a first embodiment of tie member for interconnecting the outer and inner walls of building blocks in accordance with the present invention;

Figure 7 is a top plan view of a blank from which the tie member of Figure 6 is fabricated;

Figure 8 is a second embodiment of tie member for interconnecting the outer and inner walls of building blocks in accordance with the present invention;

Figure 9 is a top plan view of a blank from which the tie member of Figure 8 is fabricated;

Figure 10 is a perspective view of a first corner block in accordance with the present invention, for use with the building block of Figure 1;

Figure 11 is a bottom view of the corner block of Figure 10;

Figure 12 is a perspective view of a second corner block in accordance with the present

invention, for use with the building block of Figure 1;

Figure 13 is a bottom view of the corner block of Figure 12;

Figure 14 is a perspective view of a brick-patterned building block in accordance with the present invention, for erecting an exterior wall structure, this block comprising an outer wall and an inner wall interconnected by means of tie members;

Figure 15 is a bottom view of the brick- patterned building block of Figure 14;

Figure 16 is an elevational end view of the brick-patterned building block of Figure 14;

Figure 17 is a perspective view of a first corner block in accordance with the present invention, for use with the building block of Figure 14;

Figure 18 is a bottom view of the corner block of Figure 17;

Figure 19 is a perspective view of a second corner block in accordance with the present invention, for use with the building block of Figure 14; and

Figure 20 is a bottom view of the corner block of Figure 19.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Figures 1 to 5 of the appended drawings illustrate a first embodiment of the building block in accordance with the present invention, generally identified by the reference 10. Block 10 is adapted, in particular but not exclusively, to erect the foundations of a building, and comprises an inner wall 12 and an outer wall 13 interconnected through a pair of tie members 14 and 15.

Although other materials can be envisaged, the inner and outer walls 12 and 13 of block 10 are advantageously made of molded concrete. As can be seen in the accompanying drawings, the respective ends of the tie members 14 and 15 are embedded in the concrete of the walls 12 and 13.

The tie members 14 and 15 will now be described.

As illustrated in Figure 7, each tie member 14,15 is made from a blank 17 of sheet metal, preferably galvanized steel. Blank 17 is bent along dashed lines such as 16 to form the tie member 14,15 of Figure 6. This type of construction is well known to those of ordinary skill in the art and accordingly will not be further described in the present description.

Referring now to Figure 6, each tie member 14,15 comprises an elongate body 18 having a

semihexagonal cross section and formed with longitudinal side flanges 19 and 20. The end 23 of the elongate body 18 to be embedded in the outer wall 13 includes flanges such as 21 and 22 perpendicular to the longitudinal axis of the body 18 to firmly retain this body 18 to the concrete of the outer wall 13. As shown in Figure 2, the end 23 of the elongate body 18 is embedded in the concrete but is not exposed (see Figure 5) on the outer face 24 of the outer wall 13, normally forming the outer side of an exterior wall structure erected by means of building blocks 10.

The elongate body 18 also comprises an end section 25 opposite to end 23. End section 25 defines a closed hollow box of hexagonal cross section. Hollow section 25 comprises a distal end wall portion 26 perpendicular to the longitudinal axis of the body 18, a proximate end wall portion 31 parallel to wall portion 26, a longitudinal side flange 27 superposed to flange 19, and a longitudinal side flange 28 superposed to flange 20. The hollow end section 25 is embedded in the concrete of the inner wall 12 (Figure 2) . Superposed flanges 19 and 27 are formed with a cut 29 and superposed flanges 20 and 28 with a cut 30 to firmly retain hollow section 25 in the concrete of the inner wall 12.

The length of hollow section 25 is equal to the thickness of the inner wall 12 whereby the distal end wall portion 26 is exposed (see Figure 4) on the outer face 32 of the inner wall 12 and the proximate end wall portion 31 is exposed on the inner face 33 of this inner wall 12. Distal end wall

portion 26 and eventually proximate end wall portion 31 therefore provide for easy screwing of building materials on the interior side of an exterior wall structure erected by means of building blocks 10. Metal screws are used for that purpose, which screws can therefore be driven through the distal end wall portion 26 only, or through both the distal 26 and proximate 31 end wall portions to extend in the space between the inner 12 and outer 13 walls of the building block 10.

One of ordinary skill in the art can also appreciate that the semihexagonal shape, including the flanges 19 and 20, provides the elongate body 18 with sufficient rigidity to properly secure the inner and outer walls 12 and 13 together.

When the block 10 is used to erect a partition or other wall structure to which building materials have to be screwed on both sides thereof, tie members such as 34 shown in Figure 8 can be used. Tie member 34 still comprises the elongate semihexagonal body 18 and the hollow end section 25 described hereinabove with reference to tie member 14,15. The modification consists of replacing the end 23 of tie member 14,15 by a second hollow end section 35 identical but symmetrical to hollow end section 25. Again, the end section 35 forms a closed hollow box of hexagonal cross section. Hollow section 35 also comprises a distal end wall portion 36 perpendicular to the longitudinal axis of the body 18, a proximate end wall portion 37 parallel to wall portion 36, a longitudinal side flange 38 superposed to flange 19,

and a longitudinal side flange 39 superposed to flange 20. The superposed flanges 20 and 39 are formed with a cut 40 while the superposed flanges 19 and 38 are provided with a similar cut (not shown) to better retain the hollow section 35 in the concrete of the outer wall 13.

Again, the length of hollow section 35 is equal to the thickness of the outer wall 13 whereby the distal end wall portion 36 is exposed on the outer face 24 of the outer wall 13 and the proximate end wall portion 37 is exposed on the inner face 41 of this outer wall 13. Distal end wall portion 36 and eventually proximate end wall portion 37 provide for easy screwing of building materials, in particular finishing materials, on the corresponding side of a wall structure erected by means of building blocks 10.

Figure 9 shows a blank 42 of sheet metal, preferably galvanized steel from which tie member 34 is made. Blank 42 is bent along dashed lines such as 43 to form the tie member 34 of Figure 8.

Of course, any material other than sheet metal but presenting similar characteristics can be used to fabricate the blanks 17 and 42 and therefore the tie members 14,15 and 34.

Referring back to Figures 1 to 5, the inner wall 12 is formed with a horizontal and longitudinal top tongue 44, a vertical end tongue 45, a horizontal and longitudinal bottom groove 46, and a vertical end groove 47. As can be seen, tongues 44

and 45 form a continuous angular tongue while grooves 46 and 47 a continuous angular groove.

The outer wall 13 is also formed with a horizontal and longitudinal top tongue 48, a vertical end tongue 49, a horizontal and longitudinal bottom groove 50, and a vertical end groove 51. Again, tongues 48 and 49 form a continuous angular tongue while grooves 50 and 51 a continuous angular groove.

The corner block 53 of Figures 10 and 11 and the corner block 54 of Figures 12 and 13 enables interconnection of perpendicular wall structures erected by means of building blocks 10 illustrated in Figure 1. The corner blocks 53 and 54 ensure adequate strength of the right angle corners of wall structure and also ensure imperviousness of such corners.

Referring to Figures 10 and 11, the corner block 53 comprises an outer right angle wall 55 and an inner right angle wall 56. Although other materials can be contemplated, the right angle walls 55 and 56 are advantageously made of molded concrete. The right angle walls 55 and 56 are secured to each other by means of tie members 57 and 58 identical to the above described tie members 14 and 15, and of which the end

23 (Figure 6) is embedded in the concrete of wall 55 and of which the hollow end section 25 (Figure 6) is embedded in the concrete of wall 56. The hollow section 25 of tie member 57 will provide for screwing from the inner side of the corner of the erected wall structure as explained in the foregoing description.

As shown in Figure 11, the distance between the edge 59 and the end edge 60 of right angle wall 55 is equal to half the distance between the edge 59 and the end edge 61 (corresponding to the length of a block 10) , whereby longitudinal offset of the blocks 10 by half the block length in the successive rows is enabled as will be described in the following description. Of course, the thickness and height of the walls 55 and 56, the spacing between these two walls, and the width and height of the tongues and grooves thereof are the same as in the case of the walls 12 and 13 of building block 10.

Also, referring to Figures 10 and 11, the right angle inner wall 56 is formed with a horizontal right angle top tongue 62, a vertical end tongue 63, a horizontal right angle bottom groove 150, and a vertical end groove 64. Tongues 62 and 63 form a continuous angular tongue while the vertical 64 and bottom 150 grooves form a continuous angular groove.

In the same manner, the right angle outer wall 55 is formed with a horizontal right angle top tongue 65, a vertical end tongue 66, a horizontal right angle bottom groove 151, and a vertical end groove 67. Again, tongues 65 and 66 form a continuous angular tongue while the vertical 67 and bottom 151 grooves form a continuous angular groove.

Referring now to Figures 12 and 13, the corner block 54, which is the inverse of corner block 53, comprises an outer right angle wall 68 and an inner right angle wall 69. Although other materials

can be contemplated, the right angle walls 68 and 69 are advantageously made of molded concrete. The right angle walls 68 and 69 are secured to each other by means of tie members 70 and 71 identical to the above described tie members 14 and 15, and of which the end 23 (Figure 6) is embedded in the concrete of wall 68 and of which the hollow end section 25 (Figure 6) is embedded in the concrete of wall 69. The hollow section 25 of tie member 70 will provide for screwing from the inner side of the corner of the wall structure as explained in the foregoing description.

As shown in Figure 13, the distance between the edge 72 and the end edge 73 of right angle wall 68 is equal to half the distance between the edge 72 and the end edge 74 (corresponding to the length of a block 10) , whereby offset of the blocks 10 by half the block length in the successive rows is enabled. Of course, the thickness and height of the walls 68 and 69, the spacing between these two walls, and the width and height of the tongues and grooves thereof are the same as in the case of the walls 12 and 13 of building block 10.

Figures 12 and 13 show the right angle inner wall 69 formed with a horizontal right angle top tongue 75, a vertical end tongue 76, a horizontal right angle bottom groove 153, and a vertical end groove 77. Tongues 75 and 76 form a continuous angular tongue while the vertical 77 and bottom 153 grooves form a continuous angular groove.

The right angle outer wall 68 is formed with a horizontal right angle top tongue 78, a vertical end tongue 79, a horizontal right angle bottom groove 152, and a vertical end groove 80. Again, tongues 78 and 79 form a continuous angular tongue while the vertical 80 and bottom 152 grooves form a continuous angular groove.

To erect a wall structure (not shown) , a first row of blocks 10 and 53 and/or 54 is installed and levelled on a concrete footing (not shown) with the vertical tongues 45, 66 and 76 of the blocks 10, 53 and 54 inserted in the vertical grooves 47, 64 or 77 of the following adjacent block of the first row, and with vertical tongues 49, 66 and 79 of the blocks 10, 53 and 54 inserted in the vertical grooves 51, 67 or 80 of the following adjacent block of that first row. To install the subsequent rows or blocks, the bottom grooves 46, 150 and 153 of blocks 10, 53 and 54 of a given row are placed on the top tongues 44, 62 and 75 of blocks 10, 53 and 54 of the lower row, and bottom grooves 50, 151 and 152 of blocks 10, 53 and 54 of the row of concern are placed on the top tongues 48, 65 and 78 of the blocks 10, 53 and 54 of the lower row, with the vertical tongues 45, 63 and 76 inserted in the vertical groove 47, 64 or 77 of the following adjacent block, and with the vertical tongues 49, 66 and 79 inserted in the vertical groove 51, 67 or 80 of the following adjacent block in the row.

At each corner of the erected wall structure, the blocks 53 and 54 alternate in the successive rows whereby the blocks 10 are

automatically and longitudinally offset by half the block length in the successive rows.

After the wall structure has been erected, polyurethane is injected in the empty space between the inner walls and the outer walls of blocks 10, 53 and 54 to thereby isolate the wall structure. Polyurethane also secures these blocks to each other to improve the rigidity of the wall structure. Then, mortar or any other binding agent is not required to assemble the building blocks. According to an alternative, the building blocks 10, 53 and 54 can be secured to each other by means of appropriate concrete glue known to those of ordinary skill in the art. The inner empty space can then be filled or not with any available material such as desert sand.

Figures 14 to 16 of the appended drawings illustrate a second embodiment of the building block in accordance with the present invention, generally identified by the reference 81. Block 81 is adapted, in particular but not exclusively, to erect an exterior wall structure of a building, and comprises an inner wall 82 and an outer wall 83 interconnected through a pair of tie members 84 and 85 identical to tie member 14,15 described in the foregoing description with reference to Figure 6.

Although other materials can be envisaged, the inner wall 82 of block 81 is advantageously made of molded concrete. As the outer face 86 of outer wall 83 imitates bricks, this outer wall 83 is advantageously made of material from which bricks are

manufactured. Again, the respective ends of the tie members 84 and 85 are embedded in the materials of the inner 82 and outer 83 walls as explained hereinabove.

The inner wall 82 is formed with a horizontal and longitudinal top tongue 87, a vertical end tongue 88, a horizontal and longitudinal bottom groove 89, and a vertical end groove 90. As shown, tongues 87 and 88 form a continuous angular tongue while grooves 89 and 90 a continuous angular groove.

In the same manner, the outer wall 83 is formed with a horizontal and longitudinal top tongue 91, a vertical end tongue 93, a horizontal and longitudinal bottom groove 94, and a vertical end groove 92. Again, tongues 91 and 93 form a continuous angular tongue while grooves 92 and 94 a continuous angular groove.

As indicated hereinabove, the outer face

86 of the outer wall 83 is patterned to imitate a row of bricks, three bricks in the illustrated example. In order to simulate brick joints, vertical rectangular channels 95 and 96 (Figures 14 and 15) are made in face 86, horizontal shoulder 97 (Figure 16) is offset downwardly with respect to horizontal shoulder 98, and vertical shoulder 100 (Figure 15) is offset toward groove 96 with respect to shoulder 99.

Figures 17 and 18 illustrate a corner block 101 and Figures 19 and 20 illustrate a corner block 102 enabling interconnection of perpendicular wall structures made of building blocks 81 as

illustrated in Figure 14. The corner blocks 101 and 102 ensure adequate strength of the right angle corners of wall structure and also ensure imperviousness of such corners.

Referring to Figures 17 and 18, the corner block 101 comprises an outer right angle wall 103 and an inner right angle wall 104. Although other materials can be contemplated, the right angle inner wall 104 is advantageously made of molded concrete, and the right angle outer wall 103 of material conventionally used to manufacture bricks. The right angle walls 103 and 104 are secured to each other by means of tie members 105 and 106 identical to the above described tie members 14 and 15, and of which the end 23 (Figure 6) is embedded in the material of wall 103 and of which the hollow end section 25

(Figure 6) is embedded in the concrete of wall 104.

The hollow section 25 of tie members 105 and 106 will provide for screwing from the inside of the corner of the erected wall structure as explained in the foregoing description.

As shown in Figures 17 and 18, surface section 107 of the outer face of the outer wall 103 is patterned to simulate one and a half (1 1/2) brick and surface section 108 one (1) brick. To simulate the brick joints, a vertical rectangular channel 109 is made in surface section 107, horizontal shoulder 110 (Figure 17) is offset downwardly with respect to horizontal shoulder 111, and vertical shoulder 112 (Figure 18) is offset toward edge 130 with respect to vertical shoulder 113.

The right angle inner wall 104 is formed with a horizontal right angle top tongue 114, a vertical end tongue 115, a horizontal right angle bottom groove 139, and a vertical end groove 116. Tongues 114 and 115 form a continuous angular tongue while the vertical 116 and bottom 139 grooves form a continuous angular groove.

In the same manner, the right angle outer wall 103 is formed with a horizontal right angle top tongue 117, a vertical end tongue 118, a horizontal right angle bottom groove 140, and a vertical end groove 119. Again, tongues 117 and 118 form a continuous angular tongue while the vertical 119 and bottom 140 grooves form a continuous angular groove.

Of course, the thickness and height of the walls 103 and 104, the spacing between these two walls, and the width and height of the tongues and grooves thereof are the same as in the case of the walls 82 and 83 of building block 81.

As illustrated in figures 19 and 20, corner block 102, which is the inverse of corner block 101, comprises an outer right angle wall 120 and an inner right angle wall 121. Although other materials can be contemplated, the right angle inner wall 121 is advantageously made of molded concrete, and the right angle outer wall 120 of material conventionally used to fabricate bricks. The right angle walls 120 and

121 are secured to each other by means of tie members

122 and 123 identical to the above described tie members 14 and 15, and of which the end 23 (figure 6)

is embedded in the material of wall 120 and of which the hollow end section 25 (figure 6) is embedded in the concrete of wall 121. The hollow section 25 of tie members 122 and 123 will provide for screwing from the inside of the corner of the erected wall structure as explained in the foregoing description.

As shown in Figures 19 and 20, surface section 124 of the outer face of the outer wall 120 is patterned to simulate one and a half (11/2) brick and surface section 125 one (1) brick. To simulate the brick joints, a vertical rectangular channel 126 is made in surface section 124, horizontal shoulder 127 (Figure 19) is offset downwardly with respect to horizontal shoulder 128, and vertical shoulder 129 (Figure 20) is offset toward channel 126 with respect to vertical shoulder 131.

The right angle inner wall 121 is formed with a horizontal right angle top tongue 132, a vertical end tongue 133, a horizontal right angle bottom groove 142, and a vertical end groove 134. Tongues 132 and 133 form a continuous angular tongue while the vertical 134 and bottom 142 grooves form a continuous angular groove.

The right angle outer wall 120 is also formed with a horizontal right angle top tongue 135, a vertical end tongue 136, a horizontal right angle bottom groove 141, and a vertical end groove 137. Again, tongues 135 and 136 form a continuous angular tongue while the vertical 137 and bottom grooves form a continuous angular groove.

Of course, the thickness and height of the walls 120 and 121, the spacing between these two walls, and the width and height of the tongues and grooves thereof are the same as in the case of the walls 82 and 83 of building block 81.

To erect an exterior wall structure (not shown) on a foundation wall structure made of blocks 10 (Figure 1) and of corner blocks 53 (Figure 10) and 54 (Figure 12) , a first row of blocks 81, 101 and 102 is installed on a top row of blocks 10 and 53 and/or 54. For that purpose, bottom grooves 89, 139 and 142 of blocks 81, 101 and 102 are placed on top tongues 44, 62 and 75 of blocks 10, 53 and 54, and bottom grooves 94, 140 and 141 of blocks 81, 101 and 102 are placed on top tongues 48, 65 and 78 of blocks 10, 53 and 54, with the vertical tongues 88, 115 and 133 inserted in the vertical groove 90, 116 or 134 of the following adjacent block of the first row, and with the vertical tongues 93, 118 and 136 inserted in the vertical groove 92, 119 or 137 of the following adjacent block in that first row. For the subsequent rows, bottom grooves 89, 139 and 142 of blocks 81, 101 and 102 of a given row are placed on top tongues 87, 114 and 132 of the blocks 81, 101 and 102 of the lower row, and bottom grooves 94, 140 and 141 of blocks 81, 101 and 102 of that given row are placed on top tongues 91, 117 and 135 of the blocks 81, 101 and 102 of the lower row, with the vertical tongues 88, 115 and 133 inserted in the vertical groove 90, 116 or 134 of the following adjacent block of the row, and with the vertical tongues 93, 118 and 136 inserted in the

vertical groove 92, 119 or 137 of the following adjacent block in that given row.

At each corner of the erected wall structure, the blocks 101 and 102 alternate in the successive rows. One can therefore appreciate that the design of the surface sections 107, 108, 124 and 135 automatically and longitudinally offset the simulated bricks by half the brick length in the successive rows. It should also be pointed out that offset of the bricks of the successive rows is possible only when a single row of bricks is simulated by each blocks 81, 101 and 102.

After the wall structure has been erected, polyurethane is injected in the empty space between the inner walls and the outer walls of blocks 81, 101 and 102 to thereby isolate the exterior wall structure. Polyurethane also secures these blocks to each other to improve the rigidity of the constructed wall structure. Then, mortar or any other binding agent is not required to assemble the building blocks. Alternatively, the building blocks 81, 101 and 102 can again be secured to each other by means of appropriate concrete glue known to those of ordinary skill in the art. The inner empty space can then be filled or not with any available material such as desert sand.

As indicated in the foregoing description, the blocks according to the invention are assembled by means of tongue and groove joints. As illustrated in the various figures of the appended drawings, the molded inner and outer walls of each building block

comprises an inner layer of hard moldable material, an intermediate layer of hard moldable material and an outer layer of hard moldable material, the intermediate layer being offset horizontally and vertically with respect to the inner and outer layers to form the tongues and grooves of these joints.

Although the present invention has been described hereinabove by way of preferred embodiments thereof, these embodiments can be modified at will, within the scope of the appended claims, without departing from the spirit and nature of the present invention.