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D. BS8110 Slab Design Brief dialog

The BS8110 Slab Design Brief has the following tabs for setting out the design parameters:

General tab

Minimum Cover These set the cover to the top and bottom of the slab.
Aggregate Size Aggregate size sets the maximum size of aggregate.
Concrete Grade

Either select a standard grade from the pull-down list or enter the concrete cube strength into the user value.

Available concrete grades include: C30, C35, C40, C45 and C50


The slabs will be designed to the forces from the envelope selected from the pull-down list.  Load Envelopes are added using the Define Envelope dialog.

Note: Top and bottom of slabs are defined by the local axis of the constituent elements.

It may or may not relate to the physical top or bottom of the slab. In order to eliminate any mismatch or confusion, please ensure that all local axes of constituent elements point in the positive y direction of the global coordinate axis.

This ensures consistency of element orientation and alignment of top and bottom of slabs with local axes.

Main Reinforcement tab


There are two ways to carryout slab design. You may set fixed bar spacing and let the program calculate acceptable bar sizes to suite or, fix the bar size and calculate acceptable bar spacing.

Wood and Armer

Select this option to use Wood & Armer moments.

Main Bar Type

Specify the strength of steel to be used for the main bars either from the available steel grades or by specifying the steel yield strength to be used (in N/mm2).  If a user strength is defined, then the appropriate bar bending dimensions need to be specified.

Specify the minimum and maximum bar sizes to be used.

Available steel grades include: T(460) or R(250)

Top/ Bottom Bar Criteria.  

Set the outer bar direction for top reinforcement to follow the ‘X’ or ‘Y’ axis of the slab.

Set bar sizes for ‘X’ and ‘Y’ directions.

Set bar spacing in the ‘X’ and ‘Y’ direction if design is based on fixed bar size.