This invention relates to an improved masonry block and in particular, relates to an improved house brick or paving brick.

DISCUSSION OF PRIOR ART

Masonry blocks such as bricks, breeze blocks have been used for many years in the construction of buildings.

Over the last fifty years the blocks have been used both as structural materials, as well as non-structural or cladding

materials. In the case of house bricks, improved reliability and consistency of manufacture has enabled the house brick to be used in situations that embrace general principles of structural design. However, masonry blocks or bricks have an inherent weakness in an incapacity to withstand tensile forces rendering masonry unsuitable in applications where bending moments and tensile stresses are required to be resisted. This weakness of masonry structures can be corrected by the use of reinforcement within the masonry. One means of reinforcing masonry is to embed reinforcements within the joints between the masonry units. However, this solution makes the construction cumbersome and expensive. It is also important to ensure that a reinforced masonry structure still utilizes the inherent high compressive strength of the masonry blocks. A further problem with the reinforcement of masonry blocks concerns the difficulty in obtaining a proper bond between the reinforcement and the blocks themselves and also the need to provide both tensile and compressive strength whilst at the same time providing access for electrical, heating or plumbing conduits.

SUMMARY OF THE INVENTION

It is in view of these problems that the present invention has been developed.

According to one aspect of the present invention there is provided a masonry block comprising upper and lower faces interconnected by side faces wherein the upper face includes a pair of mutually perpendicular straight grooves, the grooves having a cross-section to enable location of reinforcing means or conduit means within the grooves when the block is used in a masonry structure.

The grooves are preferably located centrally of the upper face of the masonry block. In one embodiment two adjacent side faces of the block are provided with centrally positioned grooves extending transversely of the respective side to meet with the adjacent groove in the upper face of the

block. The masonry block described above may be either moulded or extruded.

According to a further aspect of the present invention there is provided a lintel comprising a plurality _t 5 of masonry blocks of the kind described above positioned end to end in a horizontal array with reinforcing extending longitudinally of the array within the grooves in the upper face of each block.

In accordance with a still further aspect of the 10 present invention there is provided a prefabricated wall structure comprising a plurality of masonry blocks of the kind described above positioned side by side and one above the other in vertical and horizontal arrays and interconnected by reinforcing extending both horizontally andvertically through 15 the structure and located within the grooves provided in the faces of each block.

Each masonry block may also incorporate a centrally positioned bore terminating at the base of the intersection of the grooves and interconnecting the upper face with the 20 lower face.

The grooves in the masonry block may be of semi¬ circular, rectangular or elliptical cross section.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the present invention will now be 25 described by way of example only with reference to the accompanying drawings in which: Figure 1 is a perspective view of a masonry block in the form of a house brick, Figure 2 is a plan view of the block, Figure 3 is an underside view of the block, 30 Figure 4 is a side elevational view of the block,

, Figure 5 is an end elevational view of the block,

Figure 6 is a perspective view of a masonry block , in the form of a paving brick,

Figure 7 are side and plan views of a lintel using 35 blocks of the kind shown in Figures 1 to 5, and

Figure 8 is a side elevational view of a

prefabricated panel using blocks of the kind shown in Figures 1 to 5.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The masonry block illustrated in the accompanying drawings basically comprises two forms, a development of the standard house brick illustrated in Figures 1 to 5 and a development of a paving brick illustrated in Figure 6. The brick of Figures 1 to 5 comprises a rectangular moulded or extruded clay brick 10 having a rectangular upper face 11, a rectangular lower face 12 and opposed elongate side faces 13 and 14 with end faces 15 and 16. The dimensions of the brick are standard to a house brick and although not illustrated in the drawings, it is understood that the brick would have the external and internal coring that is standard to bricks of this kind.

The development of the brick that is the subject of this invention concerns the provision of grooves 20, 21 in at least the upper face 11 of the brick and as can be seen from Figures 1 and 2. The term "groove" as used throughout this specification is intended to cover any channel or hollow provided in a surface, including a rebate. These grooves 20, 21 comprise centrally positioned longitudinal and transverse grooves 20 and 21 respectively that extend mutually perpendicular _t to one another along the transverse and longitudinal centre lines of the upper surface 11 of the brick. The grooves 20, 21 extend to a depth of about 25mm and are of square cross section. However, it is understood that the depth and width of the grooves may vary, as may the cross section of the grooves which may be circular, rectangular or even elliptical.

In the preferred embodiment illustrated in Figures 1 to 5, grooves 22, 23 are also provided in adjacent side faces 13 and 16 of the brick, extending from the top to the bottom and joining the transverse and longitudinal grooves 20 and 21. Whilst grooves are provided in two adjacent side faces 13 and 16, it should be noted that there are no grooves

in the other two side faces 14 and 15. The provision of grooves in two adjacent side faces and not the other two faces is to enable the brick to be used in a structure that has shear reinforcement with suitable reinforcement extending vertically through the side grooves, that are positioned inwardly of the structure, whilst at the same time, ensuring that the exposed surface of the structure does not have aesthetically displeasing grooves or open slots. A further optional feature of the brick illustrated in Figures 1 to 5 is the provision of a cylindrical bore 30 centrally of the brick extending from the base of the grooves in the upper face 11 to the lower face 12 of the brick.

With respect to the embodiment shown in Figure 6 illustrating a paving brick 50, the brick 50 is substantially the same except that the depth of the brick is less than 50mm and whilst a pair of mutually perpendicular grooves 52, 53 are provided in the upper face 51 in the same manner as the embodiment illustrated in Figures 1 to 5, and an optional cylindrical bore 54 is provided to extend through the brick from the upper surface, it should be noted that with this type of brick no grooves are provided in the side faces 55 and 56. Either brick can be manufactured using conventional techniques and can be either moulded or extruded to define the grooved external surfaces. The grooves in both the side and upper surfaces of the bricks described above, serve two major functions:

(a) as positive location for reinforcing means, such as steel rod or wire that can be positioned through an array of bricks either horizontally or vertically to tie the array into a structure that can resist tensile stresses; and

(b) to act as a conduit for ancillary services such as electrical/electronic wiring, ventilation and plumbing pipe work. The optional cylindrical bore extending through the centre of the brick fulfils a similar function.

It is understood that the reinforcement may be embedded within the brick to provide a stronger structural composite with an improved and reliable bond between the reinforcement in the brick. The grooves in the brick have an additional advantageous feature that they provide a keying means to enable the brick and associated structure to be secured to existing structural members such as wooden beams. The provision of a metal or plastics conduit within the grooves or the central bore of the bricks enables a simple and reliable location of ancillary services without the necessity of the very time consuming exercise of cutting chases into the walls.

The brick described above has many potential uses, both as structural and non-structural components. It is understood that the bricks can be used together with or as a replacement of conventional house bricks in a traditional bricklaying manner using mortar. The traditional bricklaying technique known as the "English bond ¹ comprising laying one row of bricks abutting end to end and then laying the row above half a brick offset so that the join between two bricks of one row is directly beneath or above the mid span of a brick in the adjacent row thus interlocking the overall structure. It is further understood that the bricks can be laid in an entirely different manner without the use of mortar or perhaps with the use of flexible adhesives with the required strength of the structure being imparted by steel reinforcement located throughout the structure within the grooves in the.-bricks. This advantage is particularly useful in the construction of prefabricated wall panels. A prefabricated wall structure is shown in Figure

8 in which a plurality of bricks 10 are placed together off site, prefabricated with suitable steel reinforcing 70, 71 and held in an external frame 72 for transport and delivery to then be erected on site as a completed wall. The reinforcing 70, 71 can be prestressed or post stressed and extends both horizontally through the grooves 20 in the upper surfaces of bricks and vertically either through the side grooves 22 or

23 in one row and through the mortar join of the next row in an English bond structure as shown in Figure 8 or through grooves 22 or 23 where the bricks are placed vertically aligned in rows. The support frame 72 may be steel or wood and in some cases may be an integral part of the structure that is used to join the panel to the supporting structure. In one example the support frame may be metal tubing that is located in grooves on the exterior surfaces of the bricks on the perimeter of the panel. The prestressed reinforcing ensures that the panel can withstand the forces that it would be subjected to during transportation. Similarly prefabrication could be used to form arches, canopies over doors and windows or brick paving for roadside drains.

Another potential use of the brick described above is in the formation of a lintel. It is common practice to use structural steel or reinforced concrete lintels to span over an opening within a wall. However, as shown in Figure 7, by using bricks of the kind described above a plurality of bricks 10 may be laid side by side with mortar infill and suitable steel reinforcing 60 located to extend through the aligned grooves 20 in the upper surfaces to provide a brick structure that is in effect a lintel that can support loads of up to one tonne over a span of 1.5 metres. To improve the shear load resistance a plurality of spaced steel stirrups 65 may be positioned around the array of bricks. This arrangement has the advantage that it speeds up construction, does away with the necessity of the use of reinforced concrete or steel lintels and reduces the likelihood of planes of separations or cracks being formed between lintels and the adjacent masonry. A further advantage of this construction is that the grooves in the bricks can act as moisture barriers over doors and window frames built within masonry walls.

With the embodiment illustrated in Figure 6, the paving brick 50 is used inverted with suitable reinforcing on the underside so that the paving assembly can be prefabricated offsite for subsequent placement. In situations where paving has to bear high loads reinforcing can be placed in the paving

bricks to shore up the paving and reduce damage. The grooves have the further feature of allowing the paving to be positioned over water and allowing the use of electrical conduits beneath the paving, which would be located within the grooves on the underside of the brick. The paving brick is also applicable for use in roofing or other cladding environments where the grooves provide an important role in securing/anchoring the paving bricks to the adjacent structure. The brick described above is particularly useful in the design of structures that have to resist cyclonic and seismic forces. Use of this brick will substantially reduce the labour and thus expense in building such structures.

In view of its unique shape the masonry block of the invention has many advantageous applications, some important examples of which are summarized below:

(i) The masonry unit has a potential for easy fabrication of small scale construction elements like inspection pits/manholes, retaining walls, storm drain lining, face walls for reinforced earth construction etc. (ii) Economical stud walls can be built with the units, eliminating the need for special expensive metal ties. Inner cold formed steel and plaster board wall could also be replaced with an inner skin of brick for better insulation. The new brick ensures better structural integrity in a cavity wall type of construction, (iii) Because of easy placement of reinforcement, diaphram or cellular type of brick walls are easy to construct with the new masonry unit.

(iv) The masonry unit provides better anchorage for joining various structural components to masonry, eg wall plates, anchorage of floor and roof timbers, brick veneer infill in reinforced concrete or structural steel frames. This feature also makes it possible to strengthen an existing brick

wall by building additional piers into the walls.

Although in the preferred embodiment described above, reference is made to a standard house brick, it is understood that this invention is also applicable to other types of masonry structures such as breeze blocks and other concrete blocks conventionally used in the building industry where a different size block could be employed.