Peri Mmultiflex slab formwork excels on Horizon View contract
- Developer: Pegasus/Robow Investments
Principals: Gerhard Pretorius, Albert Lourens, & Peter Hudson.
- Structural Contractor: Grinaker LTA Building East
- Contracts Director: Kelvin de le Peyre
- Site Manager: Mohan Ramjawan
- Project Manager: Pegasus Projects
Principal: Gerhard Pretorius
- Architects: Ellens and Whitfield
Principal: Bill Ellens, Tony Whitfield 031) 2077145
- Consulting Structural Engineers: Young + Satharia
Principals: Rob Young, Abdool Satharia
- Quantity surveyors: Africost Quantity Surveyors
Principal: Albert Lourens
Peri products are producing such high-quality fair faced concrete finishes that they have wowed personnel from Grinaker LTA working on the R60-million contract to build the Horizon View apartment complex.
The complex incorporates upmarket apartments, shops, a service station and first-floor parking and is being built adjacent to the Gateway Shopping Centre in the heart of Umhlanga Ridge north of Durban.
Grinaker LTA is responsible for all structural work on the complex, which has a footprint of 2400m2 and includes over 15000m2 of concrete slabs and is due for completion by the company in late October 2003.
The slabs are being formed with the use of Peri Spruce Boards and GT24 girders supported by Quickstage scaffolding. The contractor is achieving such a high-quality finish that the apartment ceilings require only minor remedial rubbing and no skimming or plastering before painting.
Site manager Mohan Ramjawan said that he had never used Peri products before but that he had been frankly amazed at the superior finishes obtained and also at the time being saved by their use. The Peri formwork, he said, is being erected and struck-out in around half the time that would have been required for conventional steel systems and that the process is even more speedy because double-headed jacks are not required.
He said that the great benefits offered by the Peri products had been highlighted by the fact that the first slab on the contract had been cast using conventional steel formwork after which the switch had been made to the use of Peri Spruce Boards supported by GT24 girders.
The ease of erection combined with the technical assistance and on-the-job training provided by Peri Wiehahn’s Durban branch meant that the benefits of the products were felt from day one of their use. Very little training was required, in fact, with unskilled and semi-skilled labourers mastering the use of the products in only a few hours.
The Peri GT24 girder is one of the most versatile formwork components available on the market today according to Peri Wiehahn Technical Consultant Andrew Rowe. It’s versatility is amply demonstrated on the Horizon View Contract where it is not only being used to support the slab formwork but also for staircases, beam soffits and, later, will be utilized for sheerwall shuttering system.
The girders are extremely light weighing only 5,9kg per meter but are extremely strong having a permissible sheer force on the compression struts of 14kN and a permissible bending moment of 7kNm. With a flexural stiffness of 800kNm2 and a patented chord with finger joints the GT24 girder is highly resistant to warping.
The high strength of the girders means that fewer are required for any particular job resulting in dramatic cost savings in both formwork components, such as the girders themselves, steel whalers and floor props, and the time taken in erection and striking out. The durability of the girders also results in savings with some customers reporting that they last ten years and longer.
Peri Spruce plywood boards are coated on both sides with phenolic resin and sealed at the edges for durability and smooth finish and are designed for use as formlining for slab formwork. With a little care it is possible to achieve grout-tight joints between the boards if the edges are greased and, said Andrew Rowe, this makes the striking out process much easier as well.
The boards not only provide high-quality fair-faced concrete finishes on the slabs they are used for, but are also light and very easy to handle. Their durability makes them an extremely cost-effective formwork solution, with Griniker/LTA in Cape Town now using boards purchased originally for the Villagers office development in 2000, on their sixth contract.