Fixed moulds for box-culverts

This work involves 12 moulds for the prefabrication of 2,5m long box-culverts

These culverts are to be installed along the railway tracks of the Regional Express Network in the Brussels area. The box culverts stand straight up during the whole process.

When demoulding, the culverts are directly rotated 90° in the air with the aid of 2 overhead cranes, after which they are stored on their side as how they are going to be transported and installed.  

The outer moulds come in 2, or in 3 sections, each section can be moved individually. The inner moulds are completely straight and rigid and do not shrink. A few hours after casting the concrete, the inner moulds and the top rings are removed by pulling them up out of the concrete culvert, precisely when the concrete is sufficiently set and does not stick to the mould too much yet. The outer moulds are opened at night, after which the culverts can be taken out. The advantage of this process is that it saves a great deal of time.  As soon as the inner cores have been taken out, the cores can again be prepared and in the morning it will only take a few hours before the 12 moulds are ready to be cast again.

The inserts for the tongue and groove connections fit so well that, afterwards, the rubber seal can be positioned onto the concrete lip without any problem. Given the fact that these culvert moulds are in use for extended periods of time, each mould is equipped with a steel working platform around its entire circumference, complete with safety rails and an access ladder.