Edit recesses and core fillings (PRE-Stress)

Last modified by Fredrik Lagerström on 2023/01/04 09:20

This window is accessed through the Main reinforcements tab in the project tree manager.

A hollowcore element need not be uniform, but may instead contain additional recesses (three-dimensional cavities in the element) and core fillings. As a rule, recesses lower capacity, while core fillings increase it, relative to a pristine hollow-core. Both types are displayed on the element image, core fillings as dark grey rectangles, recesses as white rectangles.


Recesses and holes

The recesses are defined in a straight forward fashion: the three coordinates X, Y, and Z denote a single point of origin, and the width, height and length values then measure how far the we extrude the recess in each direction. During calculations, any reinforcement being cut out by the recess they will not contribute to any capacity and the reinforcement will be calculated as non-anchored in the edge of the recess.

The graphical presentation of a recess or hole are as follow:

1. (Hole at x=2000) Hole is thorough and will be cut through the wires.

2. A recess in the top (x=4000) is shown as grey and with any reinforcement in the bottom intact.

3. A recess in the bottom (x=6000) is shown in grery and with any crossing reinforcement removed. Although it is not common practice to do this, it is still possible in the software.


Core fillings

While defining a core filling, the only relevant values are the ID (which represents the core to be filled, from left, and ranges from 1 to the number of cores in the element), the start X value, and the end X value. Essentially, the core filling is a cast through part of a given core, and the two x values represent the beginning and end of that cast.


The cast concrete can be given one material property. This material will be the same for all defined core fillings.


The dead load of the core filling will be added to the dead load of the element.

Note! The automatic dead load needs to be applied to the element for it to be added.

The core filling will increase the shear capacity in ultimate limit state according to EN 1168 Annex F.3.

Note that the capacity will not be included in any Fire load combinations!

Graphical aids

The dialog also provides a graphical helper. By clicking and dragging on the representation of the beam, you can move the ruler to a given point along the beam's X axis, at which point the side image will correctly display a section of the beam.

If the element in question is not a hollowcore, the Edit recesses and core fillings button will not be displayed in the Main reinforcements tab.