Sun | Sep 24, 2017

Modern methods point to concrete as most cost efficient

Published:Monday | June 5, 2017 | 6:00 AMSyranno Baines
Motor vehicles travel on the concreted section of Fern Gully.

The differential cost between concrete and asphalt roadways since the turn of the 20th century has been as low as single digit, primarily because of the utilisation of the 1993 American Association of State Highway and Transportation Officials Guide for Design of Pavement Structure and other modern developments, says Desmond Young, civil engineer and a past president of the Jamaica Institution of Engineers.

In assessing the worsening state of asphalt-composition roads islandwide, Young listed the cost of oil, invention of new equipment, and the development of fibre reinforcement as factors which have seen concrete road figures plummet from as high as 50 per cent more.

"Locally, the design and placement is a new phenomenon and the reaction is almost always 'it costs more'," Young told The Gleaner, while noting that concrete has now become an integral part of the road network in major developed countries.

"I expect that a concrete road will cost more. There is absolutely no way a product that is designed to last 30 years will have the same cost as one designed to last seven years, that may end up lasting a year, dependent on its location. It will cost more. The issue is how much more and why."

Since the start of the year, more than $600 million has been allocated to rehabilitate approximately 104 kilometres of roadway in Trelawny, Clarendon, Manchester and Westmoreland.

While stating that there is a place for both options, Stephen Shaw, manager of communication and customer services at the National Works Agency, told The Gleaner last week that the costly initial outlay of concrete was a deciding factor in selecting which finish to apply to roadways.

... Three per cent difference between concrete and asphalt roads

Prior to its implementation in 2015, a quotation from CEMEX Jamaica showed just a three per cent difference (US$683,550 to $701,550) for two kilometres of works carried out along the access road to the Riverton City disposal site in St Andrew.

"Afforded a less-demanding maintenance programme, concrete roadways rarely endure interruptions in their operating schedule. With fewer construction zones, vehicular congestion is reduced and drive times are shortened, resulting in fuel-consumption savings for motorists, and increased productivity for commercial entities reliant on the road network," Sophia Lowe Pinnock, corporate communications and public affairs manager, Caribbean Cement Company Limited, told The Gleaner in relaying her general advice on the road situation.

"Additionally, since concrete reflects more sunlight than asphalt, it enhances night-time visibility, which can lead to reduced street-lighting requirements and lower energy bills," she said.

According to 2014 market intelligence from the Portland Cement Association in the United States, warm-mix asphalt (WMA) paving costs for an urban two-lane road in 2013 were estimated at US$852,238 per two-lane mile compared to US$878,513 per two-lane mile for a hot-mix asphalt roadway, or savings of roughly US$26,000.

Even with the WMA improvement in asphalt paving process, a concrete road was cheaper - requiring only US$769,269 per two-lane mile, or roughly US$83,000 cheaper than the lowest cost asphalt paving process. By 2020, these savings are expected to grow.

syranno.baines@gleanerjm.com