The constant increase in the development of lifestyle estates and commercial office parks in areas previously open spaces puts increased pressure on existing infrastructure, creating challenging situations that require economically viable engineered solutions. Hazeldean Road, part of the Riverwalk Project near Pretoria East, is currently undergoing upgrades to not only reduce traffic congestion between The Blyde and Silver Lakes residential estates, but also to improve stormwater and road infrastructure. Rocla and Technicrete were contracted to supply the supporting stormwater solutions.

Lourens Swanepoel, Site Agent with Kwa Mhlanga Construction said “Rocla supplied 1,564 Interlocking Joint (IJ) pipes of varying sizes, whilst sister company Technicrete delivered nearly seven kilometers of Fig 7 (semi-mountable) and Fig 10 kerbs. Technicrete also supplied 3500 m2 of Amorflex 180, a flexible heavy paver, which is specifically suited for stormwater and drainage applications that were stipulated as a requirement for this project by the engineers”.

“The pipes, kerbs and Armorflex 180 are all to be applied to the new road currently being constructed that will link Silver Lakes and the Blyde Estates with a more serviceable roadway and which will have superior drainage and stormwater solutions installed. Rocla was selected because they offered the best competitive pricing and packaged solution comprising all of the products required which included the Technicrete solutions” said Swanepoel.

Rocla’s IJ pipe is for use in stormwater applications. The male/female type joint is formed inside the wall of the pipe, which ensures no widening of the pipe, and therefore the outside dimensions of the pipe remain constant. The joint itself is used for centering the pipe during laying operations, making the process easier.

The following IJ pipes were supplied to the project:

• 730 x 450 mm IJ pipes
• 17 x 675 mm IJ pipes
• 280 x 750 mm IJ pipes
• 30 x 825 mm IJ pipes
• 122 x 900 mm IJ pipes
• 55 x 1050 mm IJ pipes
• 330 x 1350 mm IJ pipes

Armorflex 180, an internationally licensed product of Technicrete’s, is an articulating concrete block (ACB) system, specifically designed for storm-water management and ideally suited to lining of trapezoidal channels.  The Armorflex 180 blocks provide a loose but sophisticated interlocking design allowing the surface to remain flexible to movement without the cracking and spalling issues that occur with insitu cast concrete when exposed to regular stormwater or flooding incidents causing layerwork subsidence. 

Figure 7 kerbs from Technicrete are versatile precast kerbs generally used for edge restraint in the construction of roads, kerbs, gutter systems and rumble strips. Whilst Fig 10 kerbs are a light to medium duty bull-nosed edge restraint normally used for pathways where there is a possibility that vehicles can access the pathways, for example in an emergency situation, or that might need to be guided to remain on the paved paths.

Technicrete precast concrete product solutions have been installed in numerous projects around South Africa for over 50 years and offer a wide range of kerbing that will meet any developmental requirement. Swanepoel commented that he was impressed with the quality of the products from both Rocla and Technicrete, “That is, after all upon which their reputation rests” concluded Swanepoel.

Pedestrian safety alongside roadways and near to railways is an area often overlooked in infrastructure planning, but the City of Ekurhuleni, together with the Passenger Rail Agency, launched their Tembisa Pedestrian Underpass Bridges Project in April 2022 so that pedestrians and cyclists have a safer environment for walking and cycling. The development of an attractive, safe and user-friendly pedestrian and cycle underpass by the Thami Mnyele and Golden Gate rail crossings in Tembisa will also reduce fatalities.

Rocla, South Africa’s iconic manufacturer of pre-cast concrete infrastructure solutions was appointed to supply 42, 3.0m x 3.0m Jacking Culverts for the Tembisa pedestrian and cyclist underpass project by Esor Construction.

“One of the major challenges at site were the soil conditions. During the jacking phase, the backfill material causing collapses inside excavations. The friction in turn caused high jacking pressures when jacking. The jacking walls with support by 4 x 18m anchors and piles in the ground ensured the walls remained in place whilst the use of Bentonite – an absorbent aluminium phyllosilicate clay – used to cover the culverts limited friction during the jacking process” said Hendrik Ferreira, Construction Supervisor at Esor Construction.

“We have worked with Rocla on many projects over the years and always found their technical assistance invaluable. The technical team is renowned for custom designed solutions” said Ferreira.

Rocla’s Civil Engineer, Mohammad Bodhania commented that with each culvert having a mass of about 10.5 tonnes, 250 tonnes (24 culverts) were jacked into the first channel and a further 190 tonnes (18 culverts) jacked into the second channel.

“The project engineers specified that the 3m x 3m culverts were to be jacked at a depth of 4m below an existing rail embankment. We at Rocla then set about customising elements of the culvert design to accommodate this.”

Rocla’s unique Beany Block system, which is specifically designed to enhance roadway drainage, has been installed in the recent upgrades to Nelson Mandela Drive in the Port Shepstone CBD, KwaZulu-Natal (KZN).

Pieter Bodenstein, Managing Director of Margate Construction who were appointed to complete the Nelson Mandela Drive upgrades said, “The Beany Block was specified by the project engineers. It is a versatile product that addresses the need for a drainage system that allows both roadway and kerb drainage”.

“The Beany Block system is easy to install and offers an uplifting finish to the roadway. The system has been applied to both sides of the roadway. It is a very presentable and neat system, we will be utilizing the Beany Block throughout the project which is due to be completed in February 2023” said Bodenstein.

The Beany system consists of a series of Base Blocks of standard channel section and Top Blocks of inverted channel section with an opening in one side face, collecting water horizontally into the channel section. When laid end to end, they form kerb and/or surface water drainage units strong enough to withstand normal traffic loading.

“We have supplied in excess of 1,000 of each standard Top and Base Blocks as well as mountable units for driveway access and special blocks that transition between standard and mountable to the Nelson Mandela Drive project,” said Ritesh Singh, Sales Consultant for Rocla based in Newcastle, KZN. “The quantities required for this project, coupled with relatively short lead times meant that we needed to mobilize production capacities from more than one of our nationwide branches.” said Singh.

“Rocla pulled out all of the stops to ensure that we had sufficient product on site for installation. They have in fact supplied the full quota of Beany Blocks for the entire project in advance. I have worked with Rocla before on a project that required their culverts and have always been impressed by their ability to understand the challenges faced by contractors on site. Their reliability and professionalism are factors that have given them the good reputation that they have within the industry” concluded Bodenstein.

The Beany Block is a substitute for kerbs, storm water pipework (channel equivalent to and replacing 250mm – 300mm diameter pipes), kerb inlets and parts of footways. The system also reduces contractual claims, as damaged services are less likely to occur when compared to conventional drainage, as excavations involved in the installation of the system are shallow. Applications for the Beany Block are numerous and include: applications where high inlet capacity is required, wide carriageways,  as a division between vehicle and pedestrian / bicycle lanes with drainage from both sides, parking areas, taxi ranks and bus depots, wash bays and vehicle service areas, median islands and industrial areas, drainage around buildings and walkways and Toll Plazas.

When electrical distribution poles are still standing after 30 years, then you know you have made the correct decision by investing in Rocla spun concrete electricity poles. Over 20 Rocla spun concrete electricity poles, which were erected in 1992, are still standing and structurally sound after 30 years of use by Eskom in Harrismith, Free State.

“We are proud to see that our spun concrete electricity poles have survived three decades of use in the Free State. The fact that they are still structurally sound is testament to our expertise in concrete design and application” said Rocla’s Civil Engineer, Mohammad Bodhania. He added that transmission and distribution powerlines in suburban and rural areas require poles that withstand harsh environments and vandalism. “These are very important quality factors that will enable the electricity supply to be stable for the areas which they serve” said Bodhania.

The spun concrete poles, which are being used for electrification, comprise of suspension strain poles and remain structurally sound after all these years. The poles measure 15 meters with a 228 mm tip and strengths between 10kN and 30kN.

Rocla is renowned for its concrete manufacturing excellence and their spun concrete pole have become the preferred option for electrification and electric power line projects. “We continuously conduct quality checks and tests to ensure that our concrete poles comply to SANS470” said Bodhania. Spun concrete transmission and distribution poles offer a cost-effective solution due to the small servitude requirements, quicker installation turnaround time and a durable, long-term solution needing minimal maintenance.

The 2022 Concrete Manufacturers Association (CMA) honoured both Rocla and Technicrete with Engineering Excellence Awards in the Infrastructure and Paving Categories.

Group Marketing and Communications Manager for the ISG Group, Malebusa Sebatane commented that being recognised by their peers is one the highest accolades a company can receive. “Both Rocla and Technicrete are known for designing innovative solutions that overcome challenges faced on infrastructure projects by contractors”.

“Our precast concrete products are designed with one objective in mind, to provide a reliable and sustainable solution for the project. The CMA’s recognition adds value to the entire Rocla and Technicrete teams efforts to deliver a superior solution” said Sebatane.

Rocla, winner of the Infrastructure Category, supplied over 19kms of HDPE piping to Safcrete Construction for the Polokwane Waste Water Treatment Project which was commissioned by the Polokwane Municipality to upgrade an outdated sewerage system that serviced the Seshego area of Polokwane.

The pipes supplied were 1,980 x 1000 mm concrete pipes and 2,116 x 900 mm concrete pipes. The placement of each pipe also required the insertion of a rubber ring and the welding of a ‘capping strip’ on the inside of each individual joint to ensure proper sealant. Announced as the winner of the Paving Category, Technicrete’s internationally licensed Armorflex Erosion Control System 140 was selected for upgrades to major storm water systems in Mamelodi Extensions 4 and 5 north-east of Pretoria. Tefla, who undertook the project, said Armorflex’s easy installation enabled them to outsource 30% of the work to the local community enabling them to add a skills transfer element to the project.

Recent heavy rains led to the collapse of a bridge forming part of the R61 at Tsomo Junction between Ngcobo and Cofimvaba in the Eastern Cape. Rocla was contracted to supply 30 Rectangular Portal Culverts as part of the emergency rehabilitation project that was conducted along this route.

Rocla’s Rectangular Portal Culverts are specifically designed to provide for stormwater flow underneath roads. The culverts are 2100 mm x 2100 mm in size and conform to the required strength classes.

Graham Howell, Sales Consultant for Rocla in Gqeberha said “Rainbow Civils approached Rocla to supply these culverts. When a road collapses the urgency for the rehabilitation was not lost on our technicians”.

“The team at Rocla double stripped a RP2100 Gang Mould so that we could increase our manufacturing output to six culverts per day, and get the culverts on the road as quickly as possible” Howell said.

The Rocla Rectangular Portal Culvert consists of a deck and two legs and is placed on a concrete base. This base can be cast in-situ or prefabricated. The standard strength classes for these pipes are 75S, 100S and 125S. Special intermediate strengths or heavier loading requirements can be designed and manufactured. For angled road crossings, skew culverts can be manufactured.

“The only alternative roads for motorists who use the R61 regularly after the road collapsed were the R409 between the junction and the N2 at Ndabakazi, and the R408 between the N2 at Idutywa and R61 at Ncgobo commented Mike Coetzee, Regional Manager for Rainbow Civils. The rehabilitation of this section of road therefore required immediate action. We have worked with Rocla before and knew the quality of their product. We also knew their manufacturing capability would enable them to respond quickly to such a project”.

“The order was placed late January 2022 and the first Rectangular Portal Culverts arrived at site on 4^th February, with the last having been delivered on 15^th February 2022. The culverts were on schedule and were as per our required specifications. Rocla’s service is renowned throughout the industry, and this R61 project was a perfect example of how they respond to a critical situation” concluded Coetzee.

“Rocla is the preferred supplier of stormwater management products throughout South Africa due to the high standard of its manufacturing processes, ability to customise to requirement and the dedicated assistance offered from our technical engineers to assess the correct pre-cast concrete stormwater solution in cases similar to the R61 collapse” commented Howell.

“The Rocla Team pulled out all of the stops for this project with no diminishment of product quality or service standards. A great achievement” concluded Howell.

We all drive over them, complain when they go missing, but seldom realise the crucial role manholes play in the construction of underground pipelines. Rocla, who is the leading manufacturer of precast concrete in Southern Africa, designs and manufactures standard and customised manholes.

Precast concrete manholes provide a working chamber for an easy and cost-efficient access for technicians and their equipment needing to inspect or conduct maintenance.

Placed at regular intervals along the pipeline, used as a junction where stormwater pipes meet up, or where stormwater flow needs to be redirected as well as for ventilation along sewerage systems, precast concrete manholes are still the preferred choice for infrastructure projects due to their durability (lasting up to 100 years). Assembled at site, they are quick and easy to install.

Rocla’s precast concrete manhole with an interlocking joint profile together with the application of a sealing material makes for a simple yet effective solution.

The Manhole chamber sections are supplied in lengths of 1000mm, 500mm and 250mm, and are available in diameters of 750mm, 1000mm, 1250mm, 1500mm and 1800mm and 1950mm but special sizes can be accommodated. Manholes may be manufactured with step irons to facilitate a safe, steady and easy entry and exit.

Special intermediate or larger sizes can be designed and manufactured subject to a feasibility study, and Rocla engineers can assist in this evaluation process.

Accessories

Cover Slabs are available for sealing the manhole chamber. Rocla also manufactures Reducer Slabs for use in deep manhole chambers, enabling the diameter of the chamber to be reduced in order to make it more cost effective. Step Irons can be cast into the wall of the chamber whilst concrete lids are also offered as an alternative to the conventional cast iron lid.

Reported high theft rates of the cast iron lid option often leave numerous manholes open and exposed, resulting in a health and safety risk. The heavy nature of precast concrete lids, combined with the zero-resale value of the precast concrete lid reduces the temptation for theft.

Manhole components can be used with both storm water and sewer applications. In the case of sewer applications, Rocla will make use of dolomitic aggregates. Precast concrete manholes are ideal where maintenance-free, high quality solutions are required.

Rocla Sanitation partnered with Izandla Ziyagezana Trading to enter their Mkhondo based Community Cast Factory in the IMESA/CESA Excellence Awards 2021, in the Community Upliftment and Job Creation category. They were awarded second place for their Supply and Delivery of Waterborne Structures project within the rural Rustplaas Village in the Mkhondo Municipality, Mpumulanga.

The Rocla Sanitation/ Izandla Ziyagezana collaboration emerged as a result of Izandla Ziyagezana’s support for Rocla Sanitation’s Thuthukisa Initiative of ‘taking the factory to the people by empowering communities to be manufacturers in their own right’. Izandla Ziyagezana has specialised in community manufacturing and erection of low flush dignified sanitation since 2006 when the company was formed.

Dumisani Simelane, Managing Director of Izandla Ziyagezana commented “We are very proud to have been judged runner-up in the IMESA/CESA Awards. It is an acknowledgement of the importance of the work we are doing within rural communities”.

“The Rustplaas Project has so far created at least 23 new jobs, and we thank the Mkhondo local municipality for supporting this initiative. Projects such as Rustplaas show how job creation can be achieved in its simplest form through a transfer of skills on how to manufacture sanitation units of a good quality. The Rocla Sanitation Thuthukisa Initiative benefits both the local community and small businesses like my own,” said Simelane.

The Rustplaas Project enabled the local community to collaborate with on-site casting and stripping of 238 twin eco toilet top structures and pit structures in the 2020-21 financial year and a further 204 tops structures in the 2021-22 financial year. The Rustplaas community were also trained in the receiving and dispatching of casting kits and the associated materials from stores. Training of local SMME’s and community members was given in:

•           Mixing and batching

•           Casting and levelling of concrete

•           Curing and aftercare of concrete

•           Stripping and cleaning of products cast

•           Packing of stock and yard housekeeping

•           Loading and delivery of products

•           Onsite training in erecting

•           Administration and bookkeeping

Andre Labuschagne, Product Development Manager for Rocla Sanitation said “We are very pleased to have been placed second with Izandla Ziyagezana in the prestigious IMESA/CESA Awards.  This recognition for our Thuthukisa Initiative confirms our belief that many rural communities, through skills training, enjoy the benefits of healthier sanitation facilities as well as work opportunities. This has been proven through our collaboration with Izandla Ziyagezana, who from day one, have believed that this kind of initiative is imperative to the wellness of people residing in rural areas”.

“We look forward to continuing our relationship with Izandla Ziyagezana and will be collaborating with them on an 800-unit waterborne toilet project in Driefontein, Mkhondo shortly” said Labuschagne.

A concept called ‘pancake casting’ enabled Rocla Sanitation to offer a real on-site manufacturing capability that requires only a small piece of land with almost no infrastructure needed. This process involves casting one item on top of another in frameless single use moulds of a similar size in a planar form.

The panels are continuously cast one on top of another until typically full stacks of four toilets or 4 Twin Eco Pits are reached. The product is typically left to cure for two weeks. New castings can continue to be made during this curing process at other locations, using the same tools.

Labuschagne added “The communities that urgently require toilet units are often found in rural areas of the country. Many of these areas have no infrastructure. Meaning ‘to share’ the Thuthukisa Initiative’s philosophy led to the development of the ‘Community Cast’ toilet unit that can be simply manufactured by local community entrepreneurs or SMME’s and be ready for use within two weeks”.

“We would like to see our collaboration with Rocla Sanitation grow, our aim is to roll-out the Thuthukisa Initiative countrywide” commented Simelane, adding “There is so much added benefit for local communities. The goal is to provide health enhancing sanitation units to the community through the wider impact of skills transfer to the community and to also help to fight poverty and unemployment”. The IMESA/CESA Excellence Awards is a biennial event and the awards took place in Cape Town on 11 November 2021 alongside their 84th IMESA Conference. The IMESA/CESA Community Upliftment and Job Category focuses on projects demonstrating labour intensive construction, skills development, community awareness and participation.