Footing properties

Deflection ratio

This is the maximum ratio of deflection to span. Typical values are: 1/400 for standard articulated masonry veneer
1/600 for a non articulated masonry veneer
1/800 for a standard articulate masonry

1/2000 for a non articulated masonry

Care should be taken when choosing deflection ratios. This applied especially to the custom design i.e. for two storey houses or for masonry veneer structures with masonry feature walls.

Also refer to Table 3.1 AS2870-2011 for Equivalent Types of Construction.

Maximum deflection

This is the absolute limit for deflection of the slab. When a selection has been made for the deflection ratio and the cursor moves to the field for maximum deflection, a value will automatically appear in this field according to the following assumed relationships:
1/400 = 30mm

1/600 = 20mm
1/800 = 15mm
1/2000 = 10mm
A footing design will be deemed satisfactory only if it satisfies BOTH the deflection ratio (above) AND the maximum deflection.

Deflection ratio and maximum deflection can be inputed to suit the design.

Slab thickness in mm (self explanatory)

Mesh

Steel reinforcement in the slab, expressed as an area per metre of slab width.

Cover

Depth to the centre of the slab mesh reinforcement from the top of the slab.

Rectangle definitions (Standard Design only)

The following parameters can be modified for each design rectangle. You can switch between design rectangles by clicking “Next Rectangle” and “Previous Rectangle”. The current design rectangle number is displayed in the box labeled “Rectangle Number”.

Length

The length (in short and long directions) of the current design rectangle.

No. of beams

In the long direction, the value for the number of beams literally means the number of long beams, and in the short direction, it refers to the number of short beams.

Internal wall length

The total length of all internal walls within the current design rectangle.

Area calculated from bar size and number of bars

If this option is selected, then you can enter the beam reinforcement as a standard bar size (e.g. N12, N16, N20, N24, N28, N36) and number of bars top and bottom.

Reinforcement area nominated by user

This option is used if Trench Mesh is used for reinforcement. If this option is selected, then instead of selecting bar sizes and number of bars, the reinforcement is simply entered as an area in square millimetres. On selecting this option, you will see the bar size box become redundant and the labels for “No. Bars Bottom” and “No. Bars Top” change to “Reo Area Bottom” and “Reo Area Top” respectively.

Table 3.3 in AS2870-2011 can be used for Reinforcing Bar Sizes Deemed to be Equivalent to Trench Mesh Reinforcement.

Bar Size N

The bar size in millimetres. For example, for I-N12 bar, simply enter “110mm”.

Trial Beam Depth

The depth from the top of the slab to the bottom of the beam. Unlike in previous versions of CORD, this can be modified by any value at any time without disrupting the program (whereas previous CORD 6b was limited to increments of less than 50mm).

Reinforcing bar cover

The cover in millimetres to the centre of the reinforcement for external and internal beams, top and bottom. Top cover is measured from the top of the slab, and bottom cover is measured from the bottom of the beam.

Width

The web width of the beam.

Design characteristic strength of concrete

20MPa is default but can be edited as an input.

Design characteristic strength of steel

500MPa is default, but it can be edited as an input.