Ancon - Building Products

The shear stress is checked at the column face (u₀) and at a perimeter 1.5d (d = effective slab thickness) from the face of the column (u₁), with further checks at intervals of 0.75d (u₂, u₃ etc) until a perimeter is reached which does not require shear reinforcement (u_n).

The first stud is positioned 0.5d from the face of the column, with the spacing between individual studs taken at 0.75d with a maximum limit of 500mm. The maximum spacing between parallel rails is 1.5d.

A check is carried out for over-reinforcement; if this check fails, a warning message states that failure due to punching shear is possible and an increase in slab thickness will be required.

Three layouts are available, two radial (rails at 30º or 45º) and one orthogonal.

Radial Layout
Rails are positioned on the two main axes to all available column faces with either one (45º) or two rails (30º) at the corners; all perimeters have radiused corners, circular columns have a circular perimeter. The spacing between the outermost studs on the diagonal rails is kept to a maximum of 3d with secondary rails being introduced as necessary.

Rails are positioned on the main axes to all available column faces, additional rails are positioned in line with one of the main axes and set at 0.75d centres in line with the stud positions with a maximum distance between rails of 1.5d. All perimeters will be rectangular.

Where there are openings in the slab within 6d of the column (clause 3.7.7.7), a section of the slab will be ineffective and perimeter lengths will need to be reduced. The Ancon design program allows openings to be added or reductions to be applied to each perimeter as appropriate. The rail layout shown does not account for the positions of the openings and rails will need to be repositioned away from the ineffective areas.

A hard copy of the calculation method to BS 8110 is available on request.

The shear stress is checked at the column face and at a perimeter 2.0d (d = effective slab thickness) from the face of the column. If punching shear reinforcement is required, the distance to the outer control perimeter is established and the first studs are set out 0.5d from the face of the column and then at 0.75d spacing until the last studs are within 1.5d of the outer control perimeter.

Three layouts are available, two radial (rails at 30º or 45º) and one orthogonal.

Radial Layout
Rails are positioned on the two main axes to all available column faces with either one (45º) or two rails (30º) at the corners; all perimeters have radiused corners, circular columns have a circular perimeter. The tangential distance between the studs within the basic control perimeter (2d from the column face) is kept to 1.5d, outside this perimeter the maximum tangential distance is 2d with secondary rails being introduced as necessary.

Rails are positioned on the main axes to all available column faces, additional rails are positioned in line with one of the main axes and are generally set at 0.75d centres in line with the stud positions with a maximum distance between rails of 1.5d. The perimeters are the same as for radial layouts.

Where there are openings in the slab within 6d of the column (clause 6.4.2 (3)), a section of the slab will be ineffective and perimeter lengths will need to be reduced. The Ancon design program allows openings to be added or reductions to be applied to each perimeter as appropriate. The rail layout shown does not account for the positions of the openings and rails will need to be repositioned away from the ineffective areas.

A hard copy of the calculation method to BS EN 1992, Eurocode 2 is available on request.

Other Design Codes
In addition to BS 8110 and BS EN 1992, Eurocode 2, the Ancon program enables design of a Shearfix system to AS3600.