GB2250562A

GB2250562A - Interconnecting concrete section

Info

Publication number: GB2250562A
Application number: GB9026457A
Authority: GB
Inventors: Leonard Moore
Original assignee: ATCOST BUILDINGS Ltd
Current assignee: ATCOST BUILDINGS Ltd
Priority date: 1990-12-05
Filing date: 1990-12-05
Publication date: 1992-06-10
Anticipated expiration: 2010-12-05
Also published as: GB9026457D0; GB2250562B

Abstract

A joint between a precast concrete column 1 and beam 2 is formed using grooved anchor blocks 3A, 3B and a key block 8. The anchor block 3A may be welded to reinforcing bars in the beam. The anchor blocks 3B on opposite sides of the column may be welded to a connecting block 5. <IMAGE>

Description

INTERCONNECTING CONCRETE SECTIONS Pre-cast concrete beams and columns are widely used to assemble the frameworks employed in the construction of modern buildings. The horizontal beams must be interconnected with the vertical columns by connectors capable of accommodating the shear forces and moments commonly encountered in such frameworks. The connectors used at the present time are relatively complicated to manufacture and assemble. The connector described hereinafter overcomes these problems.

In the drawings: Figure 1 is a perspective view of four different arrangements of pre-cast concrete beams and columns, Figure 2 is an exploded isometric view of the components used to assemble a beam and a column in accordance with the present proposal, Figure 3 is a similar view showing the assembly of two beams and a column, and Figure 4 is a vertical section through Figure 3.

Referring to the drawings, Figure 1 shows some of the configurations in which between one and four horizontal pre-cast concrete beams 1 may be connected to a vertical column 2 as part of a framework used in the construction of a building.

A connection device for securing the end of a beam to the column comprises a pair of steel anchor blocks 3A and 3B (Figures 2 to 4) cast into the end face of the beam and a side face of the column, respectively. The anchor block 3A is welded to the steel reinforcement 4 in the form of bars running through the beam. In the example shown, a pair of anchor blocks 3B are cast into opposite faces of the column and may be welded to the ends of a compression transfer block 5 of an I shaped cross-section embedded within the column. Within the scope of the present proposal, two blocks may be cast into adjoining faces rather than opposite faces, or the column may be provided with anchor blocks cast into three or four of its faces.

Each of the anchor blocks has a vertically-extending dovetail shaped groove 6A, 6B. The groove 6A in the block 3A opens to the lower end of the block whereas that of the block 3B opens to the upper end of the block formed in the end face of the beam and the side face of the column is an elongated cavity 7A, 7B of rectangular cross-section into which opens the groove of the pertaining block. The cavity 7B in the end face of the beam opens to the underside of the beam.

The connection device also includes a steel key block 8 of double dovetail shape and so dimensioned so as to be capable of interlocking simultaneously with both anchor blocks. The width of each of the cavities 7A, 7B exceeds the overall width of the key block.

In use, the key block is inserted into the cavity 7B of the column and slid downwards into the groove 6B of the anchor block 3B, with which it interlocks. The end surface of the beam is then brought into contact with the surface of the column, with the protruding portion of the key block within the cavity 7B.

The beam is then lowered, so that the key block enters the groove 6A and interlocks with anchor block 3A, thereby fixing the beam to the column. A U-shaped wedge or shim (not shown) may then be inserted between the column and each beam so as to prevent play. Also, to prevent the key block moving vertically within the grooves in the anchor blocks as the structure moves under wind loading, stops are bolted to opposite sides of the column so as to overlie the beams. The stops are removed when the floors are fixed in place on the beams. Spaces within the anchor blocks are grouted to prevent ingress and accumulation of water.

It will be appreciated that modifications may be made to the arrangement described above. Thus, for example, a cavity may be preformed in the concrete component and the anchor block fitted therein and welded to the reinforcement. Also it is not essential for the groove of the anchor block of the beam to open into a cavity, it may open to the underside of the beam. Although a dovetail shape is to be preferred for the key block and grooves, an H-shaped key block and T-shaped grooves in the anchor blocks may be employed instead. Although it is preferred to insert the key block into the anchor block 3B, provided the key block is a sufficiently tight fit (or is otherwise held in place during assembly) it may be first inserted into the anchor block 3A.

The arrangement may be used to interlock a side face of the beam with the column, or structural building components other than beams and columns.

Claims

1. A method of interconnecting a pre-cast concrete column and a pre-cast concrete beam, comprising embedding anchor blocks within faces of the beam and column, the block in the column having an upwardly opening groove and the other block having a downwardly opening groove, sliding a key block into the upwardly opening groove such that a portion projects from the anchor block, lowering the beam to engage the projecting portion of the key block with the anchor block in the beam; the key block being so shaped as to interfit with the grooves of both anchor blocks.

2. In combination, a pre-cast concrete column and precast concrete beam interconnected by a joint comprising: a first grooved block set into a surface of the column, a second grooved block set into a surface of the beam, the groove of one block opening in an upwards direction and the groove of the other block opening in a downwards direction, and a key block slidable within the grooves and having portions interfitting with both anchor blocks so as to interlock the beam and the column.

3. For use in constructing a joint as claimed in claim 2, a pair of identical steel anchor blocks each having a dovetail shaped groove and a steel key block of double dovetail form, substantially hereinbefore described with reference to the drawings.