SA refines precast reservoir construction

SA refines precast reservoir

Precast concrete has construction helped to accelerate and mitigate risks on complex civil engineering projects the world over. This includes reservoir projects, where precast construction tends to be more efficient than cast in situ. However, the The use of precast concrete technologies provides additional levels of quality assurancereal innovation lies in the way they are built to build than cast-in-place construction countered with adequate rebar cast into on-site, says industry processes. The process can also the ring footing. specialist Corestruc. be sped up even further by including Unbonded cables are then threaded prefabricated walls. through the sleeves and joints between the The typical precast concrete roof structure comprises hollow-core slabs that are placed on precast concrete These prefabricated reservoir walls consist of precast concrete panels that have been designed to the required thickness. They have been prestressed during manufacturing and include castin sleeves that have been strategically panels. They are temporarily sealed with rubber gaskets to enable the low-viscosity grout to flow through all sleeves and joints. This grout is self-healing and achieves strengths of up to 100 MPa in a short period. It is cooled to ensure flowability beams supported by prefabricated positioned according to the design and pumped around the circumference of columns. The precast concrete columns requirements for post-tensioning on-site. the reservoir in a controlled manner. are connected to the in situ bases via After the grout has cured to a strength of cast-in components (or column shoes). Wall installation technique 80 MPa, the cables are stressed to their

These are secured to the hold-down bolts The first panel is placed and supported specified yield via special buttress panels in the same manner as a conventional temporarily and anchored by the following that have been equally spaced along steel structure. Various column base precast concrete elements. This approach the perimeter. The wall is then pinned configurations can be implemented to requires minimal propping and frees up by casting a 200 mm to 250 mm high meet project-specific requirements and space. The wall foundation, or ring footing, reinforced kicker on the wall footing on their designs must consider a minimum is designed to transfer vertical loads both sides of the wall panels. safe bearing capacity of 200 kPa at from the wall and roof to the ground. It Joints between the panels are then founding level. also translates the shear force in the grouted with a high-flow, high-strength Precast concrete reservoir roof wall due to water pressure into the ring grout. This is followed by post-tensioning structures are up to five times faster tension in the foundation. This tension is to create a watertight structure.

A modular precast approach saves time in constructing reservoirs, mitigating the potential risk of project delays and cost overruns