Franki Africa is the largest, oldest and most established geotechnical contractor in sub-Saharan Africa. Their Durban branch has extensive experience in piling and, for over 15 years, has been sourcing its concrete from Lafarge South Africa, the local market leader in ready-mixed concrete innovation.
In today’s competitive market, the productivity of a precast pile production yard is increasingly under pressure. Franki Africa was introduced to the Lafarge Chronolia™ range of ready-mixed concrete at the end of last year and it has already transformed the work scheduling in the piling yard.
As its name suggests, Chronolia™ is about time: both saving a remarkable amount of time for contractors and, importantly, being able to manage time.
Chronolia™ ready-mixed concrete is another technological breakthrough from the Lafarge Group, a world leader in building materials. The research and development focused on the clear need for customers to be able to control their construction schedules and work as rapidly as possible.
Chronolia™ has already achieved considerable success on various construction projects in the USA, Canada, Europe and more recently in South Africa.
The challenges to productivity
The challenges that Franki Africa faced to increase productivity at their precast pile yard were:
-Speed – they needed to produce as many piles as possible in the shortest time
-Space – the production yard had limited space for moulds and casting, requiring a quick turnaround on moulds
-Early strength for lifting piles – a minimum compressive strength of 20 MPa was needed before piles could be lifted
-Pile driving strength – in order to start driving the piles into the ground, a minimum compressive strength of 60 MPa at 7 days was required.
“Ideally, Franki Africa needed to be able to remove formwork from their precast piles when it optimally suited their production programme,” says Sivuyile Ngobozana, national product manager of Lafarge South Africa’s Readymix business line. “On the other hand, there was also a need to provide them with a concrete that could be transported and handled in the same way as conventional readymix.”
The Chronolia™ solution
The formulations of the range of Chronolia™ grades give two hours of slump retention followed by the selected rapid strength gain. For example, Chronolia™ 4H provides a 1 MPa minimum compressive strength 4 hours after batching; Chronolia™15H achieves a minimum compressive strength of 15 MPa, 15 hours after batching, Chronolia™ 24H guarantees a 20 MPa minimum compressive strength 24 hours after batching and finally, Chronolia™48H produces a minimum strength of 25 MPa, 48 hours after batching.
Achieving a satisfied customer
Franki Africa found that Chronolia™ 24H offered the optimum solution for their production schedule considering the various constraints. It readily met the strength criteria, while still offering similar workability to conventional concrete, enabling them to place and finish the piles with ease.
By getting an assured high strength the day after casting, it has cut right down on overtime. We now save time and money by only working the day shift, while the workability and durability of the concrete is also much better.”
Mbatha holds a Diploma in Civil Engineering and has been with Franki Africa since 1996. Franki have an impressive track record of piling projects, which include Sasol Head Office and the Discovery Building in Johannesburg, as well as the Pearls Sky Phases 1 and 2 at Umhlanga and the Bay of Plenty Pier in KwaZulu-Natal. The company has recently finished a major piling project for the Toyota Press Shop, using Chronolia™.
“Chronolia™ enables me to do my job more efficiently,” adds Mbatha. “This is helped by the excellent technical backup from Lafarge – they are always there for us and give us full support.”
More information from Chantál Stewart, Tel: +27(0)11 657 0000/ www.lafarge.co.za
Lafarge Chronolia™ ready-mixed concrete has transformed the work scheduling in Franki Africa’s Durban piling yard.
