The need for asphalt manufacturers to ensure high-quality asphalt mix production, adhere to performance-based specifications, and incorporate sustainable practices to minimise environmental impacts is a practical consideration in ensuring the longevity of South Africa’s road and bridge infrastructure, says asphalt supplier National Asphalt Cape region manager Neels Smith.

He says National Asphalt places a strong emphasis on precision in asphalt mix design, viewing it as crucial for achieving strength, durability, and resistance to rutting and cracking in road infrastructure. This entails selecting optimal aggregates, binders and additives, and maintaining strict control over mixing processes to ensure consistency and compliance with project specifications.

According to Smith, the company’s focus on long-term, quality repairs rather than temporary fixes is central to enhancing the safety and longevity of roads and bridges. Issues such as potholes, deteriorating bridges, and unpaved or inadequate roads are often ineffectively addressed by short-term solutions, leading to recurring damage and escalating maintenance costs.

National Asphalt, therefore, advocates for high-quality, long-lasting repairs that use durable materials and proven methods to address root causes, ensuring more sustainable and cost-effective infrastructure solutions.

National Asphalt uses a range of durable materials and production methods including hot mix asphalt, incorporating polymer- modified binders, cold mix asphalt, engineered for optimal stone interlocking under traffic load, recycled asphalt pavement to enhance sustainability without compromising on quality, and specialty additives, such as rubber-modified and high-modulus bitumen binders to boost performance.

“Hot mix asphalt is used to create smooth, high-quality road surfaces. It is 100% recyclable and produced using quality-certified aggregates and bitumen. Production capabilities include fixed and mobile plants ranging from 10 t/h to 160 t/h, allowing the company to tailor its solutions to varying project demands,” Smith explains.

He adds that the company’s cold mix asphalt is carefully designed to provide optimal stone interlocking after placement, ensuring it does not weaken under traffic.

The company applies advanced production and construction technologies such as Comar Twin Drum technology for applications such as asphalt compaction in road construction and maintenance to remove flushed seals, as well as the use of bitumen and asphalt to restore pavement texture and friction.

Projects, Environmental Outlook

National Asphalt is actively engaged in several large-scale road rehabilitation and upgrade projects throughout Southern Africa. These projects encompass the manufacturing, paving, and rehabilitation of asphalt for various road upgrades and maintenance projects, including the N1 upgrade between Matjiesfontein and Monument River in the Karoo region; special maintenance on national route R27 (sections 7 and 8) from the Northern Cape/Western Cape border to Calvinia, valued at around R310-million, and rehabilitation work supplying asphalt to civil engineering company Roadmac Surfacing Cape on the R45 connecting road between Pniel and Franschhoek in the Western Cape, valued at R600-million.

National Asphalt is also involved in the partial reconstruction of the R21, Pomona to Olifantsfontein project in Gauteng, where it will be supplying its Agrément South Africa-certified NATGrip product. It also recently started asphalt supply for special maintenance on the N1 from Glen Lyon and Zandkraal in the Western Cape.

Smith notes that the N1 upgrade between Matjiesfontein and Monument River is a large-scale project with a R700-million budget, estimated to be completed in late 2025. This project includes a new carriageway for a four-lane dual-carriageway road, as well as asphalt surfacing, bridge reconstructions, and other infrastructure improvements. National Asphalt is collaborating closely with the Cape-based construction contractor H & I Construction.

Further, the company notes the importance of its NATGrip Ultra-Thin Friction Course/ Open Grade asphalt and NATPatch cold mix asphalt for creating pavements with a relatively large percentage of air voids, removing pavement surface water, absorbing traffic noise and increasing friction resistance. This is coupled with the ability to patch and repair potholes and roads, enabling high-quality repairs to bituminous and concrete surfaces.

He adds that National Asphalt understands the importance of complying with relevant environmental regulations, including the National Environmental Management Act, and strives to stay informed about and adhere to changing legislation such as the Air Quality Act.

“As a company, we are aware that our responsibility to the environment does not end with obtaining environmental approvals for our plants but instead we are committed to undertaking ongoing maintenance and upgrades to ensure that our facilities remain in line with evolving environmental standards and best practices,” Smith concludes.