The ultimate adjustable jig for lifters and divers

As one of the world's most renowned mold manufacturers, Construx Weckenmann has over time developed an extensive portfolio of molds that meet the needs of precast manufacturers. Working closely with the customer, Construx Weckenmann strives to find the most suitable mold that meets all technical specifications, fits within the customer's budget and is suitable for the sizes and numbers of precast elements the customer wants to produce.

For companies producing culverts, elevator shafts or stair cores, Construx Weckenmann developed a fully adjustable formwork system many years ago: the Flexbox. Soon the Flexbox became the number one mould for many of the major European precast manufacturers of culverts and shafts. In recent years, Construx Weckenmann has supplied several Flexbox molds to a large number of precast manufacturers around the world, from the U.S. to New Zealand.

The Flexbox is by far the most robust, reliable and multifunctional mold on the market. Construx Weckenmann designed this new type of adjustable mold to produce any type of duct or core, without penetrations through the concrete element. The system is suitable for making single and double elevator shafts, step cores and culverts. The concept of the mold is based on an adjustable base frame on which all components can be fixed in position. The inner mold features four hydraulically shrinking corners which, when coupled without intermediate panels, form the minimum tube dimension. This dimension can be selected at 1,200 mm x 1,200 mm, 1,000 mm x 1,000 mm or even 900 mm x 900 mm.

By adding filler panels between the inside corners, any other internal dimension can be achieved. Adjustments can be made in increments of 250 mm, 10 mm or any size in between. Shrinking corners can have a 90° angle (for elevator shafts and stair cores), a beveled triangular angle (for culverts) or even a combination of a bevel and a 90° angle. When the mold is used both for elevator shafts and stair cores and for culverts, the beveled corners can be provided with removable attachments. The crimping corners can be operated using four separate hydraulic hand pumps or a single hydraulic unit.  

Typical net heights of the molds are 3 m and 3.5 m. By using modular interior and exterior panels, the length and width of the elements produced in the molds can reach 7.5 m x 4 m or even larger. 

After assembling the inner mold, steel base elements are placed on the base frame and against the inner mold. These base elements rest on height adjusters and can have different widths, allowing various wall thicknesses for ducts and culverts. The continuously adjustable height system makes it possible to always finish the concrete at the top of the mold.

The base elements can be flat (for elevator shafts and stair cores) or fitted with a recess (for culverts). The exterior panels are joined together in a hit-and-miss configuration. This allows any exterior dimension to be realized, regardless of adjustments to the interior mold. The outer panels and inner panels are fastened together with spindles at the bottom and with tie rods across the top of the mold. This eliminates the need for penetrations through the concrete element, resulting in a smooth and watertight surface.

Shaping the Future of Concrete

Construx Weckenmann meets customers' requirements to find the most suitable solution to all their formwork questions. The result of achieving this goal is invariably a very satisfied customer. As a fast-growing Flemish company, Construx aims to remain at the forefront of the consolidating market of formwork and mold manufacturers, as reflected in the baseline "Shaping the Future of Concrete. Construx has been a globally respected partner in this niche market since 2003. Engineering, production, project management ... everything is done in-house and from one of the seven branches in Belgium, the Netherlands or Romania. The combination of a flexible approach and a determined attitude guarantees that Construx is not only a supplier, but also a partner for its customers. With the acquisition of the German company Weckenmann last year, the Belgian company Construx becomes the worldwide reference in formwork, machinery and installations for precast concrete elements. It is also fully committed to further expanding Construx Rental, the formwork systems rental division. With the three current rental depots and with participations in a Swiss and an Irish rental company, the foundations have been laid for further expansion in the coming years. The ambition is to have our own rental companies in the Netherlands, France and Great Britain within a few years.