Kitwe-based multi-disciplinary contractor, Copperfields Mining Services, is forging ahead on a number of contracts forming part of Zambia’s Link 2000 and Link 8000 road upgrade programmes, with Copperfields’ Cat paving fleet forming a key component of the construction works.

FOR MANY decades, dating as far back as the 1950’s, the Pedicle road has served as an important transit route across one of the Democratic Republic of the Congo’s (DRC) southernmost sections (the Congo Pedicle), in the process connecting Zambia’s Copperbelt and Luapula provinces over a distance of approximately 70 km.

Interconnected by two international border posts, and travelling on the right-hand side of the road as per DRC ordinance, the route, which experiences high truck traffic volumes related to the copper mining industry in both countries, starts at Mokambo, some 16 km distant from the Zambian town of Mufulira and ends at Chembe. A single-lane bridge currently crosses over the Luapula River and then back into Zambia en route to Mansa. Without the Pedicle road option, motorists would have to drive up to a thousand kilometres around the Congo Pedicle to reach Mansa, as well as other key destinations in Luapula province, such as Kasama. Historically a two-way gravel road that becomes near impassable in the rainy season, the Pedicle road is now undergoing a major upgrade to a world-class bitumen riding surface following a 100 per cent investment by Zambia’s Roads Development Agency (RDA), with full approval by the DRC government. This 70 km carriageway will be a tolled route.

The 278 million kwacha RDA contract is being undertaken by Kitwe-based Copperfields Mining Services, an integrated mining, earthworks and road construction company, in conjunction with Rankin Engineering Consultants. Included in Copperfields’ scope of works on the Pedicle road is the widening of the Luapula River bridge to a two-lane structure. The contract was awarded in November 2012 for scheduled completion in November 2014, working within the planned constraints of the annual rainy season.

The Pedicle road forms part of the multi-billion-kwacha Link Zambia 8000 Project (also known as the Accelerated National Roads Construction Programme), with a planned target of upgrading approximately 8 000 km of national road over a five-year period.

Copperfields has also recently been awarded a further Link 8000 contact in joint venture with contractor China Henan. Valued at around K500 million, the project, situated in the Northern province, covers a total distance of approximately 115.7 km. More specifically, the scope of works entails the upgrading and realignment of a 78.1 km section between Chiengi and Kaputa; a 27.6 km section between Chiengi and Luchinda; as well as 10 km of urban roads within Kaputa.

The Kaputa urban phase forms part of an allied RDA initiative known as Pave Zambia 2000, which plans to re-pave approximately 2 000 km of township roads in 10 provincial centres, costing K1.6 billion (Source: RDA). In terms of current Link 2000 projects, Copperfields secured a contract during 2013 for township upgrades in the Copperbelt town of Ndola, where work is currently ongoing. Valued at approximately K78 million, Copperfields’ project scope covers a total area of 20.9 km, with a timeframe of approximately two years.

These urban roads are being milled and relayed with a 40 mm asphalt premix, with Copperfield’s Cat AP300D paver deployed to ensure perfect matt surfaces. Supplied and supported by Barloworld Equipment Zambia, Copperfields’ Cat AP300D forms part of a comprehensive Cat fleet, which includes the acquisition of a Cat RM500 rotary mixer deployed on the Pedicle road contract (Barloworld Equipment is the Cat dealer for Southern Africa).

Driven by a Cat C4.4 ACERT engine, the AP300D is a mid-sized hydrostatic drive wheel paver with a potential paving-width range of 650 mm to 4 m. The Cat AS3173 screed is hydraulically extendible from 1.7 m to 3.2 m and with bolt-on extensions extendible from 1.7 m to 4 m. (A hydraulic paving reduction attachment narrows the paving width to 650 mm.) Crown adjustment ranges from +4.5% to -2.5% with a screed plate vibratory frequency of 3 400 rpm (56.7 Hz). Across the board, the Cat AP300D achieves excellent traction on soft or hard base materials. A four-sensor system allows the operator to fine-tune mix delivery, with the 3.8 m³ capacity hopper delivering a 73 t/h throughput capacity.

Copperfields has invested in two mobile asphalt plants, one to support their Ndola project and the other based outside Mufulirato, which supply the DRC project with the final premix riding surface.

The new Pedicle road features a cementstabilised sub-base, with Copperfields’ Cat RM500 rotary mixer responsible for all stabilisation phases. Generating a gross power of 403 kW via its Cat C15 ACERT engine, the Cat RM500 is a high-output machine weighing in at around 28 145 kg and optimally designed for both new and reconstruction works. Width of cut is 2 438 mm, whilst the maximum depth of cut is 457 mm, enabling the RM500 to comfortably mix and stabilise two 150 mm sub-base layers in one pass.

In working this 300 mm layer, the RM500’s universal rotor – equipped with its 200 carbide-tipped bits arranged in a chevron pattern – comes into play in reworking dense in-situ materials. A three-position mode switch enables the rotor depth to be controlled manually or automatically to a preset cutting depth. This ensures exact depth control, proper sizing and thorough blending of imported and reclaimed materials. (The RM500 is fitted with a water pump and an emulsion pump, providing the flexibility to meet either cement- or bitumenstabilised pavement structure designs.)

With Copperfields’ first Cat rotary mixer acquisition, the company’s managing director, Irvin Chilufya, says that the production results have been excellent. “On the Pedicle road project we’ve never had to redo any of the areas that we’ve stabilised with the Cat RM500, which consistently provides optimal results to engineering specification.”

Road aggregates for the project are being sourced from borrow pits established at designated sections along the Pedicle road; whilse concrete elements, such as culverts, are being fabricated at Copperfields’ precast yard in Kitwe.

Established in 2004, Copperfields works across Zambia, with a core focus on the Copperbelt and Northwestern provinces, where, from inception, the company has always had strong roots in the mining sector. Alongside Copperfields’ diversification into road construction, these are now the two main pillars of its business.

“Contract mining overtime evolved to include mine civil infrastructure services, of which road construction for private and public sector clients has become an increasing component,” he explains.

Africa’s largest copper producer, Zambia is surrounded by eight countries and is strategically positioned to become a major regional trade hub, backed by GDP projections of up to eight per cent annually over the next five years. Rather than being landlocked, Zambia’s Link 8000 project intends to make the nation ‘land linked’, in the process stimulating macroeconomic growth at home. “As a Zambian civil engineering contractor, we are proud to be playing our part in paving our country’s future,” adds Chilufya.