M2 Freeway Rehabilitation
The M2 freeway, located in the south of Johannesburg’s CBD, is one of the city’s main motorways. As an important link between the N1 and N3 freeways, this roadway required some attention and rehabilitation. The project was commissioned as an emergency, after sections of the road gave way and collapsed, due largely to lack of maintenance and increased road traffic. The closing of the motorway obviously caused major inconveniences to businesses and residents alike. After Johannesburg Road Agency made the decision, the rehabilitation started on the 8th February 2019, and was completed nine months later in October 2019.
The contractor assigned to this project was Stefanutti Civils, who brought in an experienced engineer, Andre Oosthuizen. Interestingly, Andre was part of the initial road design team about 60 years ago. As many of the original drawings for this road could not be located, his input and sound advice on the project were invaluable. The rich history of this roadway necessitated the use of the best products for the job, and so it was only fitting that Sika were honoured as suppliers of choice.
Four of Sika’s products were used on the span of the road. Sikadur®-32 Normal, a bonding agent, was used to bond the new concrete to the old. Sika MonoTop®-412 NFG is the latest addition to the Sika mortar range. It has excellent performance for local conditions and was used for structural repairs of the road. It is suitable for restoration work, structural strengthening, and for preserving passivity. Sika® Ferrogard®-903 Pluswas applied to the concrete surface as a corrosion inhibitor. As a product that is based on organic compounds, it both delays the start, and reduces the rate, of corrosion. Finally, SikaTop® Seal-107 ZA, a waterproofing, chloride and carbonation protective coating was used for coating the barriers.
An approximate 150 million Rand was spent to refurbish this bridge – and looking down the road, it was most definitely money well spent.