CONCRETE POLES FOR ELECTRICITY LINES THAT WITHSTAND THE TEST OF FORCE
The days of using wooden poles for electrification projects have long passed with the advent of superior quality concrete poles that offer government and private sector infrastructure projects greater longevity, no-maintenance requirements and cost efficiencies. Rocla, part of the IS Group of companies, recently subjected their concrete cast pole to 11m-8kN of force testing at their plant in Roodepoort.
Rocla is renowned for its precast concrete manufacturing excellence and their cast concrete pole has become the preferred option for electrification and electric power line projects.
“Our cast pole is manufactured using the conventional concrete casting method” said Rocla’s Civil Engineer, Mohammad Bodhania. “It is essential that we continually conduct quality checks to ensure that the concrete pole is standing up to the required standard, and the result of the recent test show that our concrete poles reach the required SANS470 concrete pole code easily. In fact, the final test result was that our poles reached a load of 10kN without collapse”.
The recent 8kN force testing means that the pole should be able to support a load of 8kN applied at 300mm from the tip. This is known as the ultimate load of the pole. The pole has a safety factor of 2.5, meaning that in practice the pole might be subject to a maximum load of 2.5 times less than the ultimate load. This is known as the working load. The proof load of the pole is 10% higher than the working load. At proof the load must comply with the deflection, crack width and permanent set criteria set out in the SANS470 concrete pole code.
Bodhania said “We loaded our concrete pole to proof. At proof, the deflection and maximum crack width is measured. The load at which the first hair crack appears, is also noted. After loading the pole to proof, the load is released and the permeant set is measured. We then load the pole again to ultimate and the 10kN without collapse was achieved”.
The Benefits of Concrete Poles
- An optimised design enables the use of standardised fittings and ease of installation.
- They are maintenance-free while being a cost-effective long-term durable solution.
- Superior fire rating than wooden poles.
- Less prone to theft and vandalism – hardened concrete has no resale value.
“We are proud of the recent quality assessment results on our cast concrete pole. Safety and quality are all important features in the Rocla manufacturing processes. We believe we deliver a superior product, and our test results confirm that” concluded Bodhania.
Rocla also manufacture spun concrete poles, reticulation concrete poles and transmission and distribution poles. They manufacture concrete poles for stadium lighting, for the affixing of CCTV security cameras and electronic and monitoring devices, as well as park and public lighting all of which are environmentally compatible.
Rocla is part of the ISG which also includes Technicrete.