Rehabilitation of the M1 Double Decker

27 January 2020

The Johannesburg Roads Agency (JRS),
in their commitment to provide quality roads that are accessible and safe, decided
it was time for one of its major bridges to be rehabilitated. The M1 ‘double
decker’ is a highway bridge in the city of Johannesburg, between Newton and
Fordsburg, which was posing a safety threat to motorists.  

This 15 million Rand rehabilitation project,
with a bridge-span of 1.02 km, was no small task and required the expertise of
many specialists. Khato Civils (PTY) Ltd were appointed as the main contractor
for the project and assisted by 17 small, medium and micro enterprises.  A phenomenal number of 164 people were employed
on this rehabilitation process. Sika was Khato Civils’ brand of choice due
to our reliable and long-lasting products.

bridge consists of two reinforced concrete deck superstructures, one directly
above the other, that are supported on trestle-like piers. A variety of Sika
products were specified for structural repairs, structural strengthening and
coatings. SikaTop Armatec-110 EpoCem was used as a rebar protective
coating in the structural repairs, as it is highly effective for corrosion
prevention in concrete reinforcing. Also used in the repair process were the user-friendly
Sika Monotop-615 HB which is designed for thick layer concrete repairs,
especially for overhead and vertical applications; as well as the SikaGrout-212.  For structural strengthening of reinforced concrete
structures, and to increase sheer load capacity, SikaWrap-300 C was used.
The concrete surface area was treated with the Sikaguard-705 L silane water
repellent and SikaTop Seal-107, a polymer modified cement waterproof and
chloride and Carbonation resistant, liquid applied membrane coating for
concrete. To ensure that all product applications were executed correctly at
every stage, all those involved in
the project were provided with training and on site support by the Sika
team. This included training in processes such as surface preparation, product
mixing and product application.   

A major challenge to all involved was that
the motorway was under daily use by traffic. As disruption to traffic had to remain
limited, it was anticipated that it would be difficult to complete the task
within the allotted 22-month time frame. However, with the use of superior,
tailor-made products and the appointment of a committed contractor, the project
was completed, three months ahead of time. Mayor Herman Mashaba, who had stated his main concern and priority was
the safety of motorists, visited the site and was pleased with the progress.

Roads and bridges
form a critical part of the transport infrastructure, especially in a growing city,
so their maintenance and rehabilitation are important. Now complete, the mayor
and all his citizens of Johannesburg can rest assured
that the best products have been used for the project and that this
double-decker has a firm foundation. Sika firm!


is a specialty chemicals company with a leading position in the development and
production of systems and products for bonding, sealing, damping, reinforcing,
and protecting in the building sector and motor vehicle industry. Sika has
subsidiaries in 101 countries around the world and manufactures in over 300
factories. Its more than 24,500 employees generated annual sales of CHF 8.11
billion in 2019.

Read the latest issue

Latest Issue