In structural applications, Ductal^® is used without any passive reinforcing bars. Very fine, high strength steel fibres are provided to withstand secondary tensile stresses due to shear, tension, small bending moments and concentrated loads. Pre or post-tensioning counterbalances the main tensile stresses due to large bending moments. The steel fibres also provide significant ductility to the cementitious paste.

In non-structural applications, Ductal^® is used with non-metalic fibres. Passive steel reinforcement and prestressing are not required. Ductal^® has the ability to replicate the micro and nano-texture of the mould. When combined with the fluidity and the ability to have a range of colours, the result is a material that provides a high quality surface appearance together with high strength and durability.

FOOTBRIDGES & BRIDGES
The option of using concrete is often rejected: concrete is considered as unrefined and unable to provide thin and slender structures. Ductal^® allows introducing revolutionary forms with thin profiles, very slender footbridges with a multiplicity of textures and as durable as granite. The material's high bending strength enables designing structural components without any passive reinforcement, thereby permitting the thickness to be very small.

Slab four times as thin
For a footbridge deck, a 3-cm thick slab in Ductal^® could therefore be substituted for a reinforced concrete slab measuring at least 12 cm. In order to balance the primary structural stresses, the VSL technique calls for relying upon post-tensioning. The performance of Ductal^® is such that the post-tensioned cables and strands are coated to just the right extent, yielding a structural element geometry that has been specially tailored for the job.

1:30 slenderness ratio
Civil engineering structures are designed first to withstand their dead weight, which amounts to 65% of the load-bearing capacity; in other words, only 35% of this capacity actually gets allocated to the applied loading! The major reduction in dead weight inherent in Ductal^® structures, reaching on average a factor of 3, makes it possible to enhance their slenderness to a point of creating new forms. A slenderness ratio of 1:30 can thus be achieved instead of the 1:22 conventionally used. The predominant condition therefore guiding structural design becomes deformation, like for steel structures, as opposed to strength as is the case with concrete.

Colorful concrete
No aggregates are to be found in Ductal^®. Outside of the fibres, the coarsest element does not exceed 0.6 mm. This level of fineness in the material's constituents enables faithfully reproducing the shape drawn by the formwork skin. All types of moulding can now be envisaged by the designer eager to make an imprint: decorative moulding, bas-relief, hieroglyphic inscriptions, monumental motifs, grain effect, smooth finish... Moreover, away with the drab grey concrete: the colour of Ductal^® (between "traffic grey A - RAL 7042" and "window grey - RAL 7040") can be adapted to satisfy the designer's mood: white, or shaded for the solid elements in red, green or blue, etc.

Maintenance
The small quantities of material that go into building Ductal^® footbridges result in limiting material cost overruns to 10%. In reality, the cost of the completed structure depends above all on the architect's approach: for an ambitious project, construction costs using Ductal^® stay in line with those of a steel-based project, yet with the added bonus (in whatever colour) of maintenance costs being slashed.