THE EDITOR, Sir:PERMIT ME TO respond to some issues raised in your newspaper regarding the use of micro- surfacing to rehabilitate Jamaican roads.
The report in question published on Wednesday, June 2, 2004 entitled, 'Facelift for St. Mary roads' stated that several roads in St. Mary are to be repaired during the next four months under the Government's Parish Infrastructure Development Programme using the new micro-surfacing technique.
Micro-surfacing is one of the methods being used at present in the maintenance of Jamaica's main roads and while not new, it is the least used method. It is a polymer-modified cold-mix paving system that can remedy a broad range of problems on our highways and urban roads. It is being used in Jamaica and in other countries, for example, the United States, Australia, Germany and other European countries as an economical treatment for sealing and extending the service life of both urban and rural roads.
CAPABILITIES
It has added capabilities. These include treating surface wheel-rutting problems, increasing skid resistance, provides colour contrast and texture correction where the surface is too rough or too smooth. It can be used in a wide range of temperature and weather conditions as well as the filling of ruts of up to one and a half inches.
Micro-surfacing can be used to seal the cracks and halt ravelling. It is now recognised as a most cost-effective method of addressing this particular type of surface problem and a variety of others. The material protects the existing pavement, reducing deterioration caused by water and oxidation. It is applied to the existing pavement of roads with a high volume of traffic. Using micro-surfacing extends the overall pavement surface life.
NO REPLACEMENT
However, micro-surfacing does not replace the use of traditional asphalt concrete surface dressing or double-surface dressing in the construction of new pavements or the rehabilitation of existing ones. It must be emphasised that the material should be used as a road maintenance tool and not for
rehabilitation.
The fact is, it is now being used on some parochial roads to replace the double surface dressing, as a thin non-structural wearing course. This provides a smooth surface to drive on but does not significantly add to the pavement strength. We must distinguish between the uses of micro-surfacing as a maintenance tool on highways as against a wearing surface on parochial roads. It is not recommended or designed to be used on the base course layer as wearing surface.
We agree that it is very cost-effective as a maintenance tool, used at the appropriate time and on the right pavement. However, using it successfully on projects depends on strict adherence to technical specifications.
I am, etc.,
V. GEORGE PALMER
Manager
Communications &
Customer Services Dept.
National Works Agency
