City considers cement roads
11 May 2017
THE Harare City Council will be carrying out feasibility studies for the introduction of cement/concrete roads in appropriate road sections.
This comes after it has been said that some Harare roads have outlived their lifespan and the recent rains left a trail of destruction of many potholes.
Recent reports from the Environmental Management Committee said that following the report by the Director of Works Engineer Phillip Pfukwa, it was seen that concrete roads had so many benefits hence the need for the feasibility studies.
It was said that it was high time cement/concrete pavements be seriously considered because of their numerous advantages like that “concrete pavements have a longer life span and have minimal maintenance required.
“Concrete pavements have a higher initial cost but have a long life upwards to 40 years, whereas asphalt pavements are designed for a maximum of 20 years.
“A vehicle on a concrete pavement consumes 15-20 percent less fuel than when on an asphalt pavement as a concrete pavement does not get defected under the wheels of loaded vehicles. Hence there is less traction.
“Unlike asphalt pavements, concrete roads do not get damaged by the leaking fuel/oils from vehicles or extreme weather conditions like excess rain or extreme heat.
“Asphalt produces a lot of highly polluting gases at the time of melting especially during production and paving operations.
“Even over its lifetime, a lot of violations escape from a surfaced road, that is why is becomes brittle,” read the report.
Councillors and officials also noted that both products; cement concrete and asphalt concrete were re-cyclable.
“An asphalt surface has better skid resistance than a concrete one.
“However, on visibility concrete, because it’s light in colour, reflected more light than asphalt which is dark in colour. So the lighting requirements on a concrete road could be reduced. While it was technically feasible to overlay Central Business District roads with a cement-concrete overlay, the maze of utility service underneath the roads militated against that.”
It was added that there had been some discussions on this matter with cement producers Lafarge and PPC at both policy and technical levels. “They both had expressed willingness to provide technical advice, support and exposure with their experienced engineers,” further read the report.
In his report to council, Engineer Pfukwa spoke of how cement roads were first “constructed in Ohio, USA in 1891. One hundred years later, sections of the road were still in use.
“In the Zimbabwean context, asphalt, a product of the coal cooking process and fractional distillation of crude oil, was wholly imported, while materials for the production of cement and concrete were locally available.
“Since the decommissioning of coke ovens at Hwange Colliery Company and Zicosteel, no asphalt was locally produced.
“The committee then noted that along the Mvuma-Gweru Road, three trial sections were done in concrete since 1985. These were still structurally sound with very minimum maintenance on expansion joints.
“In Harare, a concrete pavement was laid on a lane servicing Long Cheng Plaza. Prior to this the site was problematic requiring continuous repairs and maintenance, but it was now virtually maintenance free,” added the report.