K+S Group, one of the world’s largest potash producers and number-one producer of salt, has invested over $4 billion in a new potash mine development northeast of Moose Jaw, Saskatchewan. Once completed, the facility will be the first potash mine constructed in the province for nearly 40 years. When operations begin, production is expected to be around 2.86 million tonnes per year.
PERI worked closely with sub-contractor FWS Industrial Ltd. to provide cost-effective formwork solutions for various elements of the project including: TRIO/MAXIMO for tunnel walls, SKYDECK for the tunnel roof slab, and customized VARIO panels for buttresses. Due to the aggressive schedule, systems that were simple, fast to work with, and easily cycled (to suit the repetitious nature of the structure) as specified by the customer.
Tunnel walls were cast in 30-metre sections, and the minimal components required per square foot of the TRIO system meant quick, systematic assembly of ganged panels was possible. The large craneable units also reduced cycle time when moving the shutters from one pour to another.
For the tunnel roof slabs, SKYDECK provided an ideal solution. The lightweight components, in conjunction with the SKYDECK Drophead, meant quick erection/striking of the material was possible, and resulted in reduced turnaround times for each slab section. This was particularly important on this project because of the site’s geographical location and the effect cold winter temperatures have on concrete curing time. To keep costs to a minimum, the design proposed by PERI utilized PEP props; this was possible as the structural dimensions were relatively small, resulting in narrower bay sizes for the SKYDECK system. This, in turn, meant shoring loads were within the capacity of the PEP prop and the customer was able to benefit from the cost savings over the stronger, but more expensive MULTIPROP.
The buttress walls were formed using VARIO. This allowed a high pour pressure while minimizing the number of ties per square foot as much as possible. As the VARIO formwork system allows a selection of plywood, barrier film was chosen to face the panels; this produced a consistent, blemish-free finish even with high utilization and re-use of the shutters. Each buttress had a battered face. To reduce erection, striking, and re-use time, the VARIO shutters were assembled into a simple rectangular shape, with a timber box-out constructed and fixed to the panel, which provided a sloping face to the poured concrete.by