Pre-tensioning in the mould

Noord General Contracting Partnership

Hendriks designed and manufactured a 37-metre long and 3.5-metre wide mould for prefabricated prestressed wide slab floors for Aannemersbedrijf v.o.f. Noord in Nieuwegein. A unique feature is that the prestressing is incorporated into the mould. This gave the builder freedom in terms of production and planning without having to make expensive investments in the floor at the temporary location.

Aannemersbedrijf v.o.f. Noord in Nieuwegein develops and builds prefab apartment buildings. The company is currently making a name for itself with the high-profile redevelopment of the Rijnhuizen neighbourhood in Nieuwegein. Here, v.o.f. Noord is constructing residential buildings such as De Ontdekking, Terraza and Fultonpark. The production of prestressed wide floor slabs is temporarily taking place on a plot of land in Nieuwegein that is yet to be developed. The plan is to move to another location once a building permit has been issued. Director Ronald Berger of v.o.f. Noord says: "We started manufacturing the pre-stressed floor slabs ourselves because our supplier's delivery times were increasing and we had to keep going."

Temporary

Berger purchased pre-stressing cylinders (from Goes Bouwtechniek in Heteren). Hendriks was called in to make the mould. Concrete is very resistant to pressure but not to tension. This is compensated for by steel reinforcement, which is placed in the concrete under tension. Commercial director Jan van Alfen of Hendriks: "We have made a provision in the mould so that the edges absorb the pre-stress. That is quite special. A commonly used alternative would be pressure bodies in the production floor. However, this requires expensive provisions in the ground, which was not desirable due to the temporary nature of the current business location." Hendriks has supplied many hundreds of metres of sheet tracks over the years. The moulds meet the crucial requirement that the formwork floor must be 100% flat for high-quality walls or floors. The CUR 100 B2 flatness requirement is no problem at all for Hendriks tracks.

Moving

Director Ronald Berger of Aannemersbedrijf v.o.f. Noord is very satisfied with the solution offered by Hendriks: “We now have approximately 80% occupancy and our own production helps us to meet the agreed delivery dates without any delays. We have many apartments in the pipeline for the coming years, so we can continue for the time being.” The moulds currently installed at the temporary location will eventually be moved to the planned new site of v.o.f. Noord. Berger: "We are still looking for a suitable location." Van Alfen: "Once that location has been found, we will move the moulds, which are currently 37 metres long and 3.5 metres wide, and extend them to 60 metres once they are in their permanent location."