Word
By Jan de Beer
An increasing number of African countries are now beginning to realise that it is worth spending a little more of State funds on new concrete roads than constantly having to find funds and manpower to repair potholed asphalt roads.
Globally concrete roads have proven immensely durable: the first concrete road built in the USA, for example, is now well over 100 years old.
In South Africa, part of a major upgrade of the old Ben Schoeman N1 highway between Johannesburg and Pretoria in the late 1980s called for the rebuilding of the highway using a concrete overlay of the existing asphalt pavement. The section of N1 that links these two Gauteng metropoles is the busiest freeway in Southern Africa.
Concrete was also used during the N1’s second major upgrade a few years later as part of the Gauteng Freeway Improvement Project, an initiative that also saw some concrete roads being built in several parts of the Gauteng province. Concrete roads, overlays and inlays have also proved their merit on KZN highways where this type of pavement has provided much-needed durability to carry the enormous volume of Gauteng trucks heavily loaded with exports to the Port of Durban.
Perhaps the most striking South African example of concrete as a durable building material for city roads – albeit on a small scale – are sections of the busy suburban road called Cape Road in Port Elizabeth which has been in use for generations.
But despite these testimonials to the merits of concrete as a durable road-building material, South African authorities have not yet expressed strong conversion to concrete – ostensibly a costlier road option. But many African countries now seem to have seen the light.
Nigeria, for a start, now seems totally converted to concrete roads, partly because wealthy local businessman, Aliko Dangote, has helped with the supply of cement from his vast empire of business interests throughout Africa. The Dangote Group’s cement production operations are based in Nigeria as well as in 14 other African countries. Dangote is, for example, the major shareholder of South Africa’s Sephaku Cement.
After the Nigerian Minister of Solid Minerals Development, Kayode Fayemi, lamented the fact that 80% of the materials used for road construction in Nigeria were imported, and that the equivalent of nearly R14 billion had to be spent on asphalt road repairs in the country, the Dangote Group stepped in and concluded a deal with the Nigerian government whereby the Group would help with the supply of cement for concrete roads, mainly as part of the Group’s corporate social responsibility programme, but also in exchange for certain tax concessions. The construction arm of the Group, AG Dangote Construction Company, is now handling the laying of the rigid pavements.
Aliko Dangote explained: “We are pushing for Nigeria to move to concrete roads. It is cheaper to build a concrete road that will last 50 years than be faced with the constant maintenance required by bitumen-based roads. Our Group’s decision to help introduce concrete roads in Nigeria is in line with the experience of other countries worldwide. For instance, the famous Autobahn in Germany was constructed with concrete and India’s popular Marine Drive in Mumbai, built in 1939, are just two examples of the durability of concrete roads.”
Nigeria has the largest road network in West Africa and the second largest south of the Sahara but the country also has a high level of seasonal rainfall which every year results in rapid deterioration of asphalt roads.
Moving further south, the Zimbabwean authorities are now also bemoaning the fact that tarred roads in the country have generally failed to last more than 10 years. Zimbabwe’s The Herald in 2017 reported that the country’s urban road network was in a “deplorable state” with Harare as well as most other cities and towns having to cope with roads littered with potholes. “Failure to maintain the Zimbabwean road network has a huge bearing on socio-economic development,” the newspaper stated calling on the government to realise that concrete roads would be the panacea for potholes.
Zimbabwean infrastructure consultancy engineer, Billy Mukasa, agreed particularly as he felt that Zimbabwe manufacturing sector produces more cement than the current national requirements and was even exporting the building material. Mukasa said: “Durable concrete roads have a potential lifespan of over 40 years and do not need frequent repair or patching like bitumen roads. Unlike asphalt roads, concrete roads are not damaged by leaking oils from vehicles or by extreme weather conditions.”
Harare’s acting town clerk, Josephine Ncube, went further and said the city would definitely be moving to concrete roads, thereby reducing the dependence on the bitumen Zimbabwe has been importing from South Africa at higher prices than the cement it could produce locally.
Her colleague, Harare town planner, Shingai Kawadza, added that although the initial cost of concrete roads may be higher, they would be more economical in the long term given the increasing capacity of cement companies in the country. He added that many African countries, such as Nigeria, Malawi, Ethiopia and South Africa, had successfully introduced concrete roads. “Globally, a noteworthy example is the road linking Hanover and Berlin in Germany which was built during World War ll and is still in good shape,” Kawadza added.
Kenya, also, has become a concrete road convert after discovering that research overseas had shown that the annual cost of ‘low-priced’ asphalt road surfaces works out at US $21 000 (nearly R304 000) more per kilometre than a concrete pavement. Among concrete road successes in Kenya is a street leading to English Street in Mombasa which, according to reports, remains “brighter and safer” than asphalt more than four decades after it was built. There are also major concrete roads in Nairobi.
In Ghana, a comparative analysis of the two types of roadways has been conducted with the government arriving at the ‘definitive conclusion’ that concrete roads were indeed more durable than asphalt. Ghana’s vice-president, Mahamudu Bawumia, said government studies had shown that a kilometre of concrete road would cost $3.8 million compared to $2.8 million for a kilometre of asphalt road. “But, more importantly, we have also learnt that a concrete road will last for at least 40 years while an asphalt road for only about 10 years,” he added. https://www.concretetrends.co.za/ct-magazine/concrete-trends-2019-may-edition/
