AfriSam

R&D Contracting’s infrastructure refurbishment project tackles corrosion issues.

Afrisam ReadyMix’s Coemore plant seeks R&D’s extensive knowledge in the refurbishment of steel infrastructures.

Afrisam ReadyMix’s Coedmore plant seeks R&D’s extensive knowledge in the refurbishment of steel infrastructures.

The Afrisam ReadyMix plant in Coedmore, KwaZulu-Natal, is one of the leading suppliers of superior quality construction materials and technical solutions. R&D Contracting was brought on board to assist in the refurbishment of much of the plant’s steel infrastructure. This included providing corrosion protection in the relatively harsh coastal environment, where humidity, salt and rust combine to create major challenges for businesses. The project required the repainting of the plant’s siloes, hoppers and conveyors. In addition, structural steel, including walkways and stanchions, required corrosion protection.

The project initially demanded that a quality control plan be developed, following a site inspection. In addition regular and ongoing site inspections are to be conducted not only by us and the client, but also by an accredited third party inspector. Our work at the plant encompassed three of the ReadyMix silos, as well as the scale platform and loading bay. We also dealt with the hoppers and four conveyors, as well as stairwells, stanchions and related infrastructure.

Since this project involves painting corrosion resistant coatings onto the steel, the one major challenge our team faced was the weather and rain delays. The environment in which the plant exists is an aggressive one. Not only are there the typical challenges coastal buildings have to deal with, including salt corrosion and humidity, but there is also the generally tough nature of the manufacturing environment. In addition, there is also an excessive amount of dust.

For this reason it was necessary to use a three-coat industrial coating system, as opposed to the usual two-coat system. We made use of Sigmacover 630, a two component, surface-tolerant, high build polyamine cured epoxy primer coating, which is a surface tolerant epoxy. The three-coat system is specified for coastal environments and involves using two coats of the chosen finish, which are applied in contrasting colours. So, for example, the intermediate coat may be red, while the top coat is painted in grey – this makes it easy to see whether any areas have been missed once the top coat has been applied. We made use of Sigmadur 550, a two component, aliphatic acrylic polyurethane finish, which offers excellent resistance to atmospheric exposure conditions and is also resistant to splashes from mineral and vegetable oils, paraffin and petroleum products and even mild chemicals.

In addition to this, we also applied what is referred to as a stripe coat, which in effect is an additional layer painted over bolts, edges, joins and hard-to-reach places. These are the areas that are most prone to corrosion, so this stripe coat simply provides an added layer of protection.

Other challenges the company dealt with during the project included ensuring timeous delivery of product ensuring the correct mixing of the epoxy coatings, the problem of soluble salts and other contaminants. The top coat colours, as requested by the client, were Squirrel Grey for the main infrastructure, Golden Yellow for handrails and Traffic Black for stanchions, while the siloes themselves were painted Traffic White.

When it comes to projects of this nature we always put safety at the forefront, and all employees working on the painting had to undergo a Level One Rope Access course, delivered by an accredited service provider. We also conducted site-specific risk assessments, to determine the best and safest ways of completing the project.

Rope access was determined as the best option over scaffolding as the Coedmore plant is live as trucks are coming in and out all day, there is moving machinery, such as the conveyers. In addition, using rope access minimised our establishment and de-establishment times for the project. Experienced people staff was brought-in to handle the rope work, and within keeping with our drive to empower local communities, many of the basic jobs that did not involve rope work were awarded to people from the area.

When it comes to working in a live environment such as this, our week had to change; instead of starting on a Monday and finishing on a Friday, we started on a Saturday and finish on a Wednesday, with employees taking the Thursday and Friday off, this way allows us to work safely on all areas of the plant such as the conveyors which are not operational on a Sunday.

Inspection lists were also regularly checked over by a technician and signed off by the supervisor. These lists covered the tools and equipment and were part of a constant safety protocol to ensure that the ropes, harnesses and ascenders and descenders remained in perfect working order.