GB2194806A - Link for reinforcement cages for use in concrete - Google Patents

Abstract

A link for use in assembling reinforcement for cages comprises a link 10 in the form of a rod bent around the perimeter of a regular polygon and looped at each apex of the polygon to form a loop lying within the perimeter of the polygon for receiving and locating a reinforcement bar. <IMAGE>

Description

SPECIFICATION Reinforcement cages The invention relates to the construction of cages for the reinforcement of concrete.

When forming a reinforced concrete pile or column, vertical steel bars need to be cast in the concrete and, in order that these should be correctly positioned within the column or pile, they are inserted as preassembled cages.

The conventional manner of forming such a cage is to insert the steel bars into a helix of narrower gauge steel rod and to tie the bars to the coils of the helix at regular intervals around its circumference. A difficulty encountered with such a construction, however, is that it is difficult to position the rods accurately while they are being tied to the coils of the helix and even if correctly assembled the cages can become distorted through rough handling as the bars can slip around the inside of the helix.

With a view to mitigating the foregoing problems, the present invention provides a link for use in assembling reinforcement cages, the link being in the form of a rod bent around the perimeter of a regular polygon and looped at each apex of the polygon to form a loop lying within the perimeter of the polygon for receiving and locating a reinforcement bar.

To assemble a cage using such links, a plurality of bars equal to the number of sides in the polygon is passed through a set of links arranged at regular intervals along the length of the cage, the bars passing through the locating loops at the apices of the links and being tied to the links in the manner conventionally employed for attachment of the bars to the coils of a continuous helix. Because the links are wrapped around each bar slipping of the bars around the circumference of the cage is prevented.

In accordance with a second aspect of the invention, there is provided a method of constructing a cage for reinforcement of concrete using links as set forth above which comprises passing a plurality of bars equal to the number of sides of the links through a set of links arranged at regular intervals along the length of the cage, the bars passing through the locating loops at the apices of the links and placing ties around the links and the bars.

In some cases, the links alone may suffice to hold the cage rigid by it is alternatively possible additionally to wrap a continuous helix around the bars and the links to form a more stable structure.

The invention will now be described further, by way of example, with reference to the accompanying drawing which is a plan view of a link of the invention.

The link 10 shown in the drawing is meant for forming a cage with six vertical bars but it will be clear that alternative numbers of sides may be employed, square and pentagonal cages being particularly common. The link 10 is formed of a single rod bent into the shape illustrated which includes six sides 12 and loops 14 at each apex. For the apex 16 at which the rod terminates, there are two loops 14 lying one above the other.

The inner diameter of the loops 14 is slightly greater than the outer diameter of the bars of the cage. In an assembled cage the bars pass though the loops 14 of several the links arranged at regular intervals along the length of the cage and are secured to the links by means of ties, which are themselves conventional.

If further strength is required for the cage, a rod may be wrapped around the bars and the links in the shape of a helix and it too may attached to the bars and to the links by means of conventional ties.

The advantage offered by the links and method of construction of the invention is that the cage cannot be distorted by movement of the bars during or after assembly and as a result the dimensions of the cage can be set with greater accuracy and the cages is more robust and better able to withstand rough transportation and handling.

1. A link for use in assembling reinforcement cages, the link being in the form of a rod bent around the perimeter of a regular polygon and looped at each apex of the polygon to form a loop lying within the perimeter of the polygon for receiving and locating a reinforcement bar.

2. A method of constructing a cage for reinforcement of concrete using links as set forth in claim 1, which method comprises passing a plurality of bars equal to the number of sides of the links through a set of links arranged at regular intervals along the length of the cage, the bars being passed through the locating loops at the apices of the links and placing ties around the links and the bars.

3. A method as claimed in claim 2, further comprising the step of wrapping a continuous helix around the bars and the links and securing the helix to the bars and the links.

4. A link for use in assembling reinforcement cages, constructed substantially as herein described with reference to and as illustrated in the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Reinforcement cages The invention relates to the construction of cages for the reinforcement of concrete. When forming a reinforced concrete pile or column, vertical steel bars need to be cast in the concrete and, in order that these should be correctly positioned within the column or pile, they are inserted as preassembled cages. The conventional manner of forming such a cage is to insert the steel bars into a helix of narrower gauge steel rod and to tie the bars to the coils of the helix at regular intervals around its circumference. A difficulty encountered with such a construction, however, is that it is difficult to position the rods accurately while they are being tied to the coils of the helix and even if correctly assembled the cages can become distorted through rough handling as the bars can slip around the inside of the helix. With a view to mitigating the foregoing problems, the present invention provides a link for use in assembling reinforcement cages, the link being in the form of a rod bent around the perimeter of a regular polygon and looped at each apex of the polygon to form a loop lying within the perimeter of the polygon for receiving and locating a reinforcement bar. To assemble a cage using such links, a plurality of bars equal to the number of sides in the polygon is passed through a set of links arranged at regular intervals along the length of the cage, the bars passing through the locating loops at the apices of the links and being tied to the links in the manner conventionally employed for attachment of the bars to the coils of a continuous helix. Because the links are wrapped around each bar slipping of the bars around the circumference of the cage is prevented. In accordance with a second aspect of the invention, there is provided a method of constructing a cage for reinforcement of concrete using links as set forth above which comprises passing a plurality of bars equal to the number of sides of the links through a set of links arranged at regular intervals along the length of the cage, the bars passing through the locating loops at the apices of the links and placing ties around the links and the bars. In some cases, the links alone may suffice to hold the cage rigid by it is alternatively possible additionally to wrap a continuous helix around the bars and the links to form a more stable structure. The invention will now be described further, by way of example, with reference to the accompanying drawing which is a plan view of a link of the invention. The link 10 shown in the drawing is meant for forming a cage with six vertical bars but it will be clear that alternative numbers of sides may be employed, square and pentagonal cages being particularly common. The link 10 is formed of a single rod bent into the shape illustrated which includes six sides 12 and loops 14 at each apex. For the apex 16 at which the rod terminates, there are two loops 14 lying one above the other. The inner diameter of the loops 14 is slightly greater than the outer diameter of the bars of the cage. In an assembled cage the bars pass though the loops 14 of several the links arranged at regular intervals along the length of the cage and are secured to the links by means of ties, which are themselves conventional. If further strength is required for the cage, a rod may be wrapped around the bars and the links in the shape of a helix and it too may attached to the bars and to the links by means of conventional ties. The advantage offered by the links and method of construction of the invention is that the cage cannot be distorted by movement of the bars during or after assembly and as a result the dimensions of the cage can be set with greater accuracy and the cages is more robust and better able to withstand rough transportation and handling. CLAIMS

1. A link for use in assembling reinforcement cages, the link being in the form of a rod bent around the perimeter of a regular polygon and looped at each apex of the polygon to form a loop lying within the perimeter of the polygon for receiving and locating a reinforcement bar.

2. A method of constructing a cage for reinforcement of concrete using links as set forth in claim 1, which method comprises passing a plurality of bars equal to the number of sides of the links through a set of links arranged at regular intervals along the length of the cage, the bars being passed through the locating loops at the apices of the links and placing ties around the links and the bars.

3. A method as claimed in claim 2, further comprising the step of wrapping a continuous helix around the bars and the links and securing the helix to the bars and the links.

4. A link for use in assembling reinforcement cages, constructed substantially as herein described with reference to and as illustrated in the accompanying drawing.