No population can survive without potable water, making the management of water a crucial element of local municipality responsibility. The need to maintain and upgrade water related pipelines and related technical equipment, as has recently been highlighted, is of paramount importance to ensure that community health, hygiene and safety are not comprised.
Rocla, part of the IS Group, has been contracted to supply a part of the 1,100 metres of jacking pipe for two of the 19 sections (1 x 90-m and 1 x 288-m sections) for underground construction to the upgrades for the Palmiet Pumping Station to Signal Hill Reservoir project currently being constructed for Rand Water.
Two contractors, Wepex and Esor, both sought product from Rocla because of their superior jacking pipe offering and availability. Contracts mnager, Pipe Jacking Division for Wepex, Luke Woodhams, said: “The Palmiet/Signal Hill project is an 18-month contract with hard rock, alongside residential and national roads, needing to be blasted. The Rocla 100D jacking pipe has a nominal diameter of 2,500 mm and an outside diameter of 3,000 mm and a proof load of 250 kN/m. It is an ideal pipe for this application – to carry water supplies for human consumption as well as to withstand the immense pressure of vehicle weight,” said Woodhams.
Steel pipes will be inserted into the jacking pipe for extra support and for their anti-corrosion properties.
Self-Compacting Concrete
The Rocla 100D jacking pipe is made from self-compacting concrete and complies with SANS 677. Manufactured through a vertical-cast process, self-compacting concrete renders a better surface finish, while the benefit of the vertical-cast (VC) process instead of the traditional roller-suspended (RS) process is that a more consistent thickness throughout the product is achieved compared to the RS operator-related effort of compaction.
The VC process gives an improved compaction around the reinforcement, improving the bond to the reinforcement and offering greater ease in filling extremely thin-walled sections.
Self-compacting concrete can increase safety on the job by eliminating the need for consolidation; offers improved pumpability and labour efficiencies; shorter construction time making it a cost-effective option. It can be placed at a faster rate without automated vibration and therefore requires less screeding. A quicker concrete vehicle turn-around time is facilitated, assisting contractors in servicing a site more quickly.
Woodhams added “Rocla had the right pipe with good availability. Their product is of an excellent quality and at a good price. We are very pleased with the service the company has given us and we would definitely use Rocla again when we can”.
Civil Engineering and Construction Group, Esor is involved in the Phase B section of the Palmiet/Signal Hill project. Anton Naude, director of Pipejacking commented: “The Rocla product is very competitive, the jacking pipes need to be able to last the lifespan of the project, which they will easily do due the quality of the pipes. These are huge jacking pipes that have an approximate mass of 5,680 kg per metre and a mass of 8,518 kg per pipe.”
“Currently the upgrades are running under the road from Alberton to Germiston, and it was essential that we had the right product and the right technology in place to eliminate traffic disruption” said Naude.
“One of the challenges facing contractors on this Rand Water upgrade project is that the old pipes are running parallel to newly positioned jacking pipes, and it is imperative that the old piping is not damaged while the installation of the new Rocla replacement jacking pipe is under way. We are confident all will be well,” he added.
Pipe jacking is a technology where specifically made pipes are tunnelled through the ground by hydraulic jacks, eliminating the need to dig up the road infrastructure. It offers greater transparency in terms of time and costs and is an environmentally friendly process.
Further information is available from: Malebusa Sebatane, Tel: +27(0)11 674 6957 / www.rocla.co.za
