Gestión de Endeudamiento Anexo 6.1. Endeudamiento

The last step in the dimensioning process is the construction of the individual bar layers and the production of the reinforcement drawings.

Change again to the 2D presentation and ensure that both directions of the bottom rein forcement are shown. Since the presentation of the results is no longer necessary, one can switch it off, by deactivating the results layer using the adjacent button in the layer group Reinforcement and then causing the figure to be redrawn (F2). Diameters and distributions should now be assigned to the reinforcement fields. Select in addition both large fields, open the reinforcement field dialogue (e.g. ’Attributes’ in the Context Menu) and change to the Register/Design/. The input fields diameterĬ and subdivision a are not yet active, but contain a default value (light grey), which one can adopt by clicking on both the buttons:

required area existing area

As additional information for the production of the reinforcement plan one can specify in the Register/Attributes/ one tick each and an anchorage length. Now press the button [Apply], whereby both fields are fixed and the effective existing reinforcement area be sides that statically required are shown (see above). Now select the additional reinforce ment layer and choose a spacing of 15 cm (by clicking on the button a with subsequent

choose a spacing of 15 cm and activate the default diameter of 14 mm. Also choose here an anchorage length for both ends and press [Apply]. The remaining statically unuseable fields can now be selected and deleted with the DELkey. Thus the reinforcement ar rangement is constructed and one can close the reinforcement dialogue.

In order to provide the display with more de tail open the Dialogue ’Display Settings’ with the adjacent button and change to the Regis ter/Reinforcement/. Choose there detailed field labelling and specify for the view 1:100 a text height of 3 mm. Press also ’Renumber Fields’, whereby the input fields are provided with an increasing position number, begin ning with the bottom layers. Afterwards close the dialogue again.

A reinforcement sketch now appears on the screen, which is similar to a plan diagram. Prepare this by moving the labelling points optically somewhat higher (see above, box ’Positioning the Field Labels’). Thus the dimensioning is complete and one can print the drawings (see figure below).

If one has a CAD system that can exchange reinforcement data with CEDRUS5, one now has the possibility of exporting the reinforcement arrangement. Thereby all reinforce ment layers with their attributes (diameter, spacing, anchorage condition etc.) are written to a file, which can then be read into the CAD system, in order to finish detailing the reinforcement there (i.e. constructional additions, splices etc.) and to produce the reinforcement plan.

To do this open with the adjacent register button the dialogue ’Layout Settings’. Click there on the button ’Export’ and then specify the name of the target file, on which one wants to store the complete reinforcement data. The default value is a file named after the layout in the ’User’ directory of the project.

D 3 Reinforcement Module Part D Reinforcement and

. CEDRUS-5 supports several reinforcement formats, which one can specify using the Main Menu ’’Options>CAD Interfaces>Export Reinforcement”. Basically one has the choice be- tween CEDRUS’s own ECB format, a series of special formats (part of module CAD inter- faces) and the industry standard DXF, which, however, only permits the transfer of a reinforce- ment drawing in the form of lines and text and thus is only of limited usefulness. CEDRUS-5 also supports several proprietary formats of CAD vendors, which one can acquire by purchas- ing the option ’CAD Interfaces’.

D 4 Ultimate Load Module Part D Reinforcement and

D 4 Ultimate Load Module

The Ultimate Load Module permits the nonlinear calculation of a reinforced concrete slab with a given reinforcement arrangement. In this chapter the basic concepts of the calculation are explained in detail and the procedure for an ultimate load calculation is demonstrated by means of an example.

D 4.1 Basic Concepts

Modern codes permit the use of nonlinear calculation methods to verify the limit states for serviceability and ultimate load. The Ultimate Load Module of CEDRUS5 is restricted to calculations of the structural safety, i.e. ultimate load, and can provide, therefore, no information on crack widths and bending deflections under working loads. Since the reinforcement has to be known before the calculation starts and only one load combina tion can be investigated simultaneously (i.e. no process of critical action combination for limit states is possible), it is not suitable for dimensioning tasks. With the Ultimate Load Module, however, strength reserves of existing structures can be determined or the rotational requirement can be estimated at the end of plastic dimensioning.

Nonlinear Calculation Method

By nonlinear methods are meant FE calculations, which take into account and exploit the nonlinear properties of the construction materials. Beginning with an initial stress and deformation state the behaviour of the structure is analysed with specified rein forcement and a stepwise increase of the loading (see D 2.3.1). Up to now these ex tremely computationally intensive calculation methods, however, have been little used in practice, although they have already been employed in research for a long time. One of the main reasons for this is the nature of nonlinear calculations, in which even small variation in the input parameters can cause big differences in the results. In view of the poorly understood properties of reinforced concrete structures (initial stress/strain state, material parameters, support conditions, loading etc.) these methods demand from the user much experience in problem modelling and interpreting the results. This difficulty grows with the complexity of the models employed, which is why in the Ultimate Load Module of CEDRUS5 a simple material model with few parameters is used (see D 2.1.1), which essentially determines the ultimate load. In combination with the simple calcula tion control (see D 4.1.3) and the vivid graphical output the simplicity of the model makes the interpretation of the results easier. With the Ultimate Load Module of CE DRUS5 the required user input is limited to the reinforcement arrangement and the loading. There is no specification of a material model. Thus ultimate load calculations are also amenable to practicing engineers, who do not possess specialist knowledge in the field of nonlinear FE methods.