Architectural concrete and safety
Construction of a school and sports hall: Mammut 350 defies high pressures
The Swiss community of Holderbank is growing
Hence, the local school urgently needed an extension with a sports hall. This was built in architectural concrete quality.
The architects planned a two-storey wooden structure with classrooms and additional rooms. A concrete sports hall was designed as the substructure for this school building. The sports hall consists of a more than 8 m high longitudinal wall built completely below ground and opposite this an approximately 6 m high wall erected on a slope. Seven columns were then placed on this wall to compensate for the height difference and support 23-ton joists pushed into recesses in the higher wall. Daylight streams into the sports hall between these columns.
One of the requirements demanded of ERNE AG Bauunternehmung was that the walls and columns should stand out with an architectural concrete finish. This experienced company relied on the rugged Mammut 350 wall formwork, which effortlessly fulfilled the combined requirements on architectural concrete and large-format walls. Thanks to the symmetrical tie hole and joint pattern, the system ensures a pleasing appearance when used both horizontally and vertically, and makes a significant contribution to the overall outcome of a construction project from an architectural viewpoint.
New alkus facings for top results
For this project 300/250 panels were fitted with brand-new alkus all-plastic facings, thus ensuring a smooth, flawless surface finish throughout without any undesirable discolouration. The investment in the durable facing was well worthwhile, as it can be easily repaired using the same material and its surface ground for reuse hundreds of times. Thus, it more than pays for itself over the course of its life cycle compared to significantly less durable plywood facings that need to be replaced on a regular basis.
Rapid construction progress and consistent concrete finishes were achieved by easily and safely combining several 300 cm high panels with widths 250 and 125 cm on the ground to produce total surface areas of more than 55 m² that were then supplemented with three working platforms from the SecuritBasic safety system installed one on top of the other. The entire construction was then lifted to its destination by crane and after a 7.30 m wide pouring operation simply relocated for the next cycle. In this way, the architects’ requirements regarding smooth, large-format surfaces were fulfilled. To pour each column, two large-size panels were i connected to a 125 cm wide panel and stabilised
using alignment rails.
Fresh-concrete pressure of 100 kN/m²
The high load capacity of the Mammut 350 formwork was an important aspect during this project. The team at ERNE AG Bauunternehmung used the particularly strong 20 mm tie rods. This enabled the formwork to withstand a fresh-concrete pressure of 100 kN/m² over the entire surface. To be on the safe side, the formwork was closed using two nuts
for each tie rod. After all, it’s better to be safe than sorry.
This also applies to the modular Triplex heavy-duty props that transferred the forces acting on the formwork into the ground as well as to the Securit- Basic working platforms that can be attached firmly with only one single part – the flange screw – to ensure comfortable and safe working conditions. Thus, nothing else stood in the way of rapid construction
processes and top results.