GB2201700A - Wall ties for concrete block constructions - Google Patents

Abstract

The tie system comprises a pair of plate members 1 each of which is to be laid along the upper face of a course of concrete blocks 3 and a tiebar 16 with a pair of pins 14, 15 extending upwards and downwards from tile tiebar. The pins penetrate holes 11, 12, 13 in the plate members to engage internal faces of the blocks; the outer faces thereof are engaged by respective upwardly extending flanges 6 and downwardly extending flanges 5 of the plate members. <IMAGE>

Description

Ties for Concrete Block Constructions The present invention is concerned with ties for concrete block constructions for use, for example, in the construction of reinforced concrete walls.

Reinforced concrete walls are normally constructed using expensive "pan shutteringt' (usually steel or plywood panels) held together by bolting, bracing with tubular scaffolding and/or channel section irons. In the conventional method, the panels are erected to two faces of the wall, the steel reinforcement is installed in the cavity between the.

panels, and the concrete is poured in with vibration. When the concrete has set, the steel/plywood panels are removed, cleaned, oiled for reuse. The smooth concrete faces have then to be "keyed" (roughened) to receive cement and sand rendering.

We have now devised a tie system for concrete block construction, which enables two skins of brickwork to be used as permanent shuttering (in lieu of pan shuttering).

According to the present invention there is provided a concrete block tie system, comprising a pair of plate members each capable of lying along the upper face of a respective skin of a course of concrete blocks, said plate members each having a depending flange capable of engaging the outer face of the course of blocks on which the plate member is laid and an upstanding flange capable of engaging the outer face of the next higher course of blocks, each of said plate members having at least one aperture at a predetermined separation from said upstanding and depending flanges; and a tiebar having a pair of pins each arranged to penetrate an aperture in a respective plate member so as to engage facing faces of said courses of blocks and define a cavity between said skins of predetermined spacing.

The separation between the flanges and the apertures may correspond to the thickness of a standard concrete block (for example 2 inch, 3 inch or 4 inch); it is particularly preferred that each plate member has a series of such apertures such that it can be used for a range of such blocks.

The tie system according to the invention can enable the respective skins of blocks to be used as permanent shuttering (in lieu of pan shuttering) by placing the plate members on the horizontal mortar joints of blockwork at suitable intervals as work proceeds. The tiebar may then be located with its pins penetrating apertures in the plate members depending on the thickness of the concrete blocks.

Steel reinforcement can be installed in the cavity between the two skins of concrete, vertically and horizontally, in the traditional manner. The steel reinforcement is tied to the spacer bar as work proceeds, keeping the reinforcement in correct position and in true line.

The vertical joints of the blockwork are left open (no mortar), typically with a dimension of approximately 1/2"; when the concrete infill is poured and vibrated, the concrete will fill the joint ensuring a strong bond and will indicate visually that the cavity between the skins of blockwork has been correctly filled and is free of air pockets. The concrete blocks being of rough texture and with raked joints form a good "key" for cement and sand rendering without special preparation.

The pins in the tiebar preferably project both upwardly and downwardly, so as to engage the inner faces of the two skins of blockwork above and below the mortar joint.

A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective view illustrating the use of an exemplary block tie system in construction of two skins of block; and Figure 2 is a schematic view showing a plan, elevation and section of concrete block permanent shuttering (formwork), showing the tie system in place, together with reinforcement between the two skins of blocks.

Referring to Figure 1, there are shown a pair of plate members 1,2 each located on the top of a course of a respective skin of blockwork 3,4. Plate member 1 has a depending flange 5 and an upstanding flange 6 approximately half the width of the depending flange (for example, flange 6 may be about 1/2 inch wide, while flange 5 may be about 1.25 inch wide). Depending flange 5 is designed to bridge the vertical joint 7 between adjacent blocks 8,9. The upstanding flange 6 is intended to engage the outer face of the next course of bricks above (not shown).

Plate member 1 is provided with one large hole 10 (of diameter about one inch, for example), which serves as a key for mortar, and a series of three holes 11, 12, 13 spaced from flange 5 by predetermined amounts (e.g. 2 inches, 3 inches and 4 inches respectively) corresponding to thicknesses of conventional blocks. The plate member 2 is generally similar (and like parts are denoted by like reference numerals).

Holes 11, 12, 13 are sized to receive dowels 14, 15 securely fixed to generally flat tiebar 16. The tiebar 16 with dowels 14,15 is such that it acts as a spacer to give the correct spacing between skins 3,4, and such that it co-operates with plate members 1,2 to substantially prevent the skins from spreading out when the cavity is filled with concrete and vibrated.

The plate members may be of any suitable material such as, for example, stainless steel, galvanised or coated steel or plastics (for example, injection-moulded plastics).

The tiebar again may be of any suitable material such as, for example, mild steel or stainless steel.

Referring to Figure 2 (in which like parts to those of Figure 1 are denoted by like reference numerals), the elevation shows a block wall 17 having vertical joints 18; overlying the top edges of some of the vertical joints are flanges 5,6 of a series of plate members of a tie system as illustrated in Figure 1.

Referring to the plan and section, a series of plate members 1 lie on one course of blocks 19 and a series of plate members 2 lie on a second course of blocks 20, with tiebars 16 linking the plate members and spacing the skins of blocks.

Claims (7)

1. CLAIMS:

   l. A concrete block tie system, which comprises a pair of plate members each arranged to lie along the upper face of a respective skin of a course of concrete blocks, said plate members each having a depending flange capable of engaging the outer face of the course of blocks on which the plate member is to be laid and an upstanding flange capable of engaging the outer face of the next higher course of blocks, each of said plate members having at least one aperture at a predetermined separation from said upstanding and depending flanges; and a tiebar having a pair of pins each arranged to penetrate an aperture in a respective plate member so as to engage facing faces of said courses of blocks and define a cavity between said skins of predetermined spacing.
2. 2. A tie system according to claim 1, in which the separation between each said flange and a respective aperture corresponds to the thickness of a standard concrete block.
3. 3. A tie system according to claim 1 or 2, in which each said plate member has a series of said apertures therethrough, along the length thereof.
4. 4. A tie system according to any of claims 1 to 3, in which said pins project both upwardly and downwardly from said tiebar.
5. 5. A tie system according to any of claims 1 to 4, in which said plate members are apertured in the region where they lie upon the concrete blocks, so as to provide a key for mortar laid on said concrete blocks over said plate members.
6. 6. A concrete block tie; system, substantially as described herein with reference to Figure 1 of the accompanying drawings.
7. 7. A method of construction of a reinforced concrete wall structure, which comprises providing a plurality of plate members and tiebars as defined in any of claims 1 to 5, there being two plate members per tiebar; locating half of said plate members on the upper face of a first course of concrete blocks and the other half thereof on a second course of blocks spaced from and substantially parallel to said first course, the plate members being located with their depending flanges contiguous with the outer face of the respective course of blocks; locating said tiebars with a first pin thereof penetrating an aperture in one of said plate members on said first course and a second pin thereof penetrating an aperture in one of said plate members on said second course; installing reinforcement in the spacing between said courses; charging said space with concrete; and allowing said concrete to set.