Engineering office

Ultra-high performance, fiber-reinforced concrete design recommendations published by SETRA/AFGC in January 2002 include Ductal®, under ‘UHPFRC’ materials. The recommendations are adaptations of the BAEL and BPEL design codes and validate conventional structures such as girders, columns and slabs. They can be reinforced, prestressed or without passive reinforcement. The recommendations are written so that conventional design tools can be used and engineers traditional ways of working are altered as little as possible. Among the properties displayed by Ductal® are high compression strength and tensile or flexural strengths, which eliminate the need for secondary reinforcement and shear strain.

The compression behavior law is similar to the HPC behavior law: elastico-plastic, as stated in the BAEL extension, from B60 to B80.
The same form is used, only the numbers change.

Due to the presence of fibers, tensile strength is significant and is taken into account in the serviceability limit state and ultimate limit state.
A simple behavior law is proposed and can be entered, point by point, in the modeling software. The only difference is that the behavior law depends on the height of the flexion section.

For shear strain validation formulas have been adapted, and proposed resembling the Eurocode 2 formulas.

Simple shapes can be pre-dimensioned by using spreadsheets or calculated by hand.

Finite element analysis can be required for complex shapes, in which case the following conventional approach can be applied:
- FEA in linear elastic
- local verification with a non-linear material model.

Alternatively, software that takes into account the non-linearity of the material may be used.