Concrete Or Asphalt: The Road Pavement Question, By Habib Mohammed
Over the last couple of months, there has been ongoing discourse about the use of concrete pavement in road construction as against Asphalt, which has been the norm since only God knows when.
I have decided to join in, in this discourse, not as an advocate for concrete paved roads or a supporter of the continued use of asphalt paving. My intention is simply to highlight what I know about the two methods of road construction, so followers of this matter could argue from a bit more informed position.
I think it was Nigeria’s very own top multibillionaire, Alhaji Aliko Dangote(aka Alicash, aka Alhaji Putin) who first put this issue on the front burner(I could be wrong). My first reaction was, ‘Bad guy Alhaji Putin wants to create monoploy for his 42.5R grade cement’. While this could be true(knowing the man and his business philsophy), I have to say that most of the reasons he adduced were genuine.
Lots of people, and even some professional organisations have bought into this idea. However, I am concerned that no one is interested in actually juxtaposing the merits and demerits of both materials. We just seem to be polishing and beatifying concrete paved roads. Hence, this blogpost.
It is true that concrete road paving has an average life span of close to 40 years. A lot has also been said about how maintenance work wouldn’t be needed on it as frequently as is the case with asphalt paving. But no one is telling us that one of the major problems with concrete pavement is the overly high construction cost. Concrete paving, in some cases incorporates the use of reinforcement steel(depending on the pavement method in use), when this is added to the cost of concrete, the bill could be well over six(6) times the construction cost for Asphalt pavement.
I work for a major player in the construction industry. The company charges about a hundred and fifty thousand(150,000) naira per cubic metre of concrete. Using this information, the cost of concrete paving alone on a single lane of 10 metre length will amount to over three and half million(3,500,000) naira . And even this, is just for the plain(unreinforced) concrete pavement. If the reinforced concrete pavement(most commonly used in western countries) were to be used, you can be sure the price will reach the high heavens. Please note that other necessary materials and labour will also be factored into the total bill. Asphalt paving over the same length and width will take less than one million, five hundred thousand(1,500,000) naira. That I can assure.
Maintenance is also another issue that has been well stated as a good reason for jettisoning asphalt. While it is true that concrete paved roads, if well constructed, doesn’t need as much maintenance as asphalt paved roads does, people have clearly omitted the fact that Asphalt is recyclable and could be used over and over again. Wherever, cracks and potholes appear in asphalt paved roads, that portion alone could easily be repaired. So, maintenance cost for asphalt paved roads are always very minimal. Same cant be said for concrete. In most cases, concrete roads are paved in slabs of about five(5) metres in length and four and a half(4.5) metres in width(i.e for the plain unreinforced concrete pavement). If cracks or potholes appear in them, the entire slab needs to be replaced. This means that the construction cost of that slab is most likely its maintenance cost.
Another issue that needs to be clearly stated here is that of safety. I think above all considerations, this should be top most. Asphalt paved roads have a better safety attribute than concrete paved roads. Asphalt has better traction and roads constructed with asphalt are skid resistant in any type of weather. I don’t understand why no one has acknowledged this very important failing of concrete paved roads.
Finally, the most common claim that asphalt paved roads are not durable doesn’t completely hold water with me. I am surprised that even professional organisations have pushed this arguement. Its a bit embarrassing. Perpetual pavement could be said to be Asphalt paved roads’ answer to the durability question. This method of asphalt paving, if strictly adhered to, with top quality earthwork operation will prolong the durability of the road beyond the ten(10) years durability limit for Asphalt being bandied around.
Now, this post is not to say that concrete isn’t a good material for road pavement. In my view, concrete is an alternative material for road pavement. Whether it is a better one or not is left to you readers to discern.