B8 is suitable for the calculation of reinforced concrete beams and pretensioned girders (longline method). The software performs all required verifications of the loadbearing capacity (also for the accidental and earthquake design situations) as well as serviceability verifications. The comprehensive dataentry work is facilitated by several wellstructured dataentry screens and supported by help files that include information about permissible and required values as well as plausibility checks.
Available standards
 DIN EN 199211/NA  NA to BS EN 199211  EN 199211  PN EN 199211  ÖNORM B 199211
Girder types
You can calculate the following girder types with the help of B8:  Girder with parallel flanges  Symmetrical and asymmetrical girders with saddle or groove  Singlepitch roof girder In addition to calculating the entire girder system, you can also calculate individual cross sections.
Shapes of cross sections
B8 allows you to calculate all relevant cross sections. In addition to the simplified definition of rectangular cross sections, Tbeams and Twowebbed Tbeams you can also define any type of compact single and doublesymmetrical cross section with the help of the socalled layer cross section.
You can optionally supplement the defined cross sections with castinplace complements such as  solid slabs  solid slabs with prefabricated formwork or  complements to the slab
You can define enlarged bearing cross sections for the support area at the end of the girder.
Structural systems
You can calculate the girder in the final state, during its storage, as a singlespan girder or as a cantilevered singlespan girder. For the erecting state, you can examine a separate structural system aligned to the location of the suspension points.
The structural systems that result from auxiliary supports installed during the installation of the castinplace concrete complements are automatically taken into account in the calculation of the cross sections.
Loads
B8 allows you to define permanently vertical, subsequent permanent and variable loads as
 uniformly distributed linear loads  concentrated loads and moments  trapezoidal loads and triangular loads
The assignment of standardspecific or userdefined actions is supported by a dialog.
B8 performs automatically the calculation of the selfweight including that of the castinplace concrete complement.
Reinforcement
 Multilayer pretensioned reinforcement with insulation, if applicable  Multilayer untensioned reinforcement
In B8, the reinforcement is assumed parallel to the top or bottom flange.
Durability requirements
The combination of all decisive exposition classes produces the following results:
 Minimum concrete class  Minimum concrete cover  Permissible crack width  Whether a decompression analysis is required
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The results are produced separately for the top and bottom of the girder.
In addition to this, you can find special features such as airentrained concrete, aggregate for wear, decrease of the dimensional allowance for prefabricated components.
Verifications
Ultimate limit state (USL):  Bending with longitudinal force (including resisting tensile force coverage)  Shear resistance, for castinplace supplements inclusive bearing capacity of the joints  Lateral buckling in the installed state and in the erecting state (method by Stiglat and Mann)  Determination of the tensile splitting reinforcement  Anchorage of the prestressing reinforcement
Serviceability limit state (SLS):
 Concrete stresses, steel stresses (prestressed steel, reinforcing steel)  Crack width (loading, minimum reinforcement), verification of the decompression, if required  Deflection for a selectable load combination of the SLS with consideration of state II including tension stiffening and shrinkage  Changes in length due to temperature, creep and shrinkage
All verifications are performed at the beginning and the end of creep stages, which are determined by the casting and the usage of the girder. The creep factor and the shrinkage strain are calculated in detail and are taken into account in the verifications. The pretension remaining after the deduction of losses due to creep, shrinkage and relaxation is considered effective.
Results
The calculation is based on a section grid laid over the girder. Every verification is performed on each individual cross section of the grid. The result list reveals the section with the highest utilization or the lowest safety reserve, which is the critical section for this verification.
A quick overview is available via the view of the critical cross sections, which also shows the utilization of the respective verification.
The graphical representation of the utilization behaviour allows the easy identification of points where a limit is exceeded. The values processed in the graphical representation can also be displayed in the form of a table.
In order to find out why the limit in a verification was exceeded, you can display each calculation step in detail. An advisor suggests appropriate corrections.
Design settings
The user can control the inclusion of calculation assumptions that are permissible in particular cases of application. The control options include:
 Definition of independent imposed and live loads  Combination of permanent loads for each span separately  Verification of the crack width limitation without minimum reinforcement  Definition of a gradual application of the pretensioning force  Definition of reduced material safety coefficients for precast components  The consideration of a thermal treatment allows the utilization of increased strength at the moment when tensioning force applies and the reduction of the creep factors.  At the moment when the tensioning force applies, a higher permissible compressive stress and an increased compressive resistance of the concrete can be taken into account, if the corresponding prerequisites are satisfied.esults
