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  • Flexible or rigid pavements for Nigerian roads?

    Flexible or rigid pavements for Nigerian roads?

    • By Odinaka Victor Okonkwo

    There have been several talks on the use of flexible or rigid pavements for Nigerian roads. The merits and demerits of both have been well noted. While rigid pavements are costlier, they can withstand heavier loading. The flexible pavement has a shorter lifespan and is easier to maintain. Interestingly these are based on statistics from other developed countries. To find out what is best for Nigeria we need to make decisions based on our own experience.

    While we can conclude that flexible pavements have a shorter lifespan of 15 to 20years, is that the reality in Nigeria? The answer is no. If our roads do last for that long the consideration for rigid pavements would not have started.

    To be able to propose an option for the country, there is need to briefly x-ray the various components of the road pavement and their functions. These are the subgrade – the natural surface upon which a road is built; the sub base – the layer of granular material (laterite) that receives the load from the base course and transfers it to the subgrade. It is also used as a fill material to establish the required slopes of the road; the base course – the layer consisting of mostly crushed stones that serves the purpose of receiving the concentrated loads (point loads) from vehicle wheels and distributes them (spreads them out) over a wider area enabling the sub-base material to carry them. It is the load bearing layer (stratum) in a road pavement; and the asphaltic layer – the final layer that provides a waterproof layer that protects the base course material from water. It also provides a wear-resistance surface that protects the base course from wears due to braking action and screeching of vehicle tires.

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    The asphaltic layers and the base course are the two most importance components of the road pavement. While the base course material is more rigid and capable of carrying vehicular loads and spreading it over a larger area of the weaker subbase material, it is weak when exposed to water. It also has a low resistance to wear. If a vehicle on high speed suddenly brakes on top of a well laid base course, some of the materials of the base course are removed, raising dust. An asphaltic layer on the other hand is very resistant to wear. The screeching of tires on it rather wears off the tires and leaves the asphalt intact. The asphalt is also very resistant to water. Exposure to water does not cause it to lose strength. Asphalts are however not a high load bearing material like the base course. It is flexible and bends under load and so is not excellent at distributing loads over wider surface areas like the base course.

    The relationship between the base course and asphaltic layer is therefore symbiotic. The base course material carries the load while the asphaltic layer protects the base course material against wear and water.

    The rigid pavement

    A rigid pavement mainly varies from the flexible pavement because of the replacement of the asphalt layer with Portland cement concrete. This is a material that attempts to possess all the good qualities of the crushed stone base course and asphalt. It has very good mechanical properties and so can carry loads. It is resistant to water (does not disintegrate in water), the high grade versions of it is also resistant to wear. Its strength (load carrying capacity) can be increased with the addition of steel reinforcement bars. It appears to be the one final bus-stop with regards to road pavements. However its two major components (cement and reinforcement rods) are expensive. In standard rigid pavement designs, the Portland cement concrete replaces the asphaltic layer in a flexible pavement. To resist wears due to braking actions of vehicles it must be well prepared concrete of high grade (30 and above).

    While we propose a sudden shift from flexible pavements to rigid pavements, it is important to know why most of the flexible pavements do not achieve their envisaged lifespan in Nigeria. I think this hovers around quality control during road construction and increased axle loads from vehicles. The construction of flexible pavement requires some painstaking quality control measures which are increasingly harder to enforce. The sub-base is compacted to a required density (standard compaction) and tested at every specified distance (chainage) to ensure this quality is achieved. The same applies to the base course layer. The base course material must also be laid to a specified thickness. The priming of the base course surface is done with a cutback (diluted) bitumen, its quality is hard to enforce. The asphalt is laid at a high temperature and compacted at a specified temperature for it to retain the desired properties. These are hardly noted or enforced in today’s road construction in Nigeria. This is outside what happens in the asphalt plants and the fact that they are limited in number and most contractors have to patronize the ones close to the road construction site irrespective of the quality of their products.

    Why Portland cement concrete?

    Quality enforcement is way easier with Portland cement concrete than with asphaltic concrete. We just specify the mix ratios of the cement, fine and coarse aggregate by volume. The cement come in their finished forms in bags ready for use unlike bitumen that will have to be diluted (cut-back) and heated by the contractor often with little enforceable quality control measures. The actual mixing of the cement, water and aggregates is just a simple mechanical process requiring no heating hence most contractors can easily procure a concrete mixing machine unlike the asphalt plant which is more complex and expensive to operate. This is the primary reason why building construction appears to have succeeded more than road construction in Nigeria. Our buildings rely more on Portland cement concrete and we have seen a better percentage of our buildings achieve their expected lifespan unlike our roads.

    To achieve success in our road construction we must borrow a leaf from the successes of our building construction. We must design and build roads that require less hard-to-implement quality controls. When many contractors found it difficult to achieve concretes of grade 30 and above, our building construction teams began to rely on concrete grade 20. When getting steel bars of grade 460 was an issue, we began relying on grade 410 and 380. These were factored into the designs of our buildings leading to success.

     If we rely on high grade concrete for our roads to get a wear resistant surface, that will be the beginning of our failure in the implementation of rigid pavements.

    Reinforced concrete no doubt is a better load bearing layer than the compacted crushed rock base course. It requires little or no compaction to achieve this strength. It also requires little reinforcement to provide a tougher layer than the compacted crushed rock base course. We can replace the base course layer with a reinforced concrete layer. This is precisely what we do in most of our paved compounds. 

    A good asphaltic concrete (produced and laid following strict adherence to quality) will be flexible and impermeable even after many years. It bends without the development of cracks. It offers a surface highly resistant to wear. Hence it completely protects the base course layer from water and wear. When we compromise standards in asphalt production and placement, we have an asphaltic layer that develops small cracks under loads. These cracks allow water to percolate and make contact with the base course (compacted crushed stone) material. After some period of contact with water the base course material disintegrates, is eroded leading to the formation of potholes. Most of our poorly prepared asphalts have a higher resistance to wear than our cement concrete. Hence it can protect any material underneath it from wear.

    I propose a hybrid of flexible and rigid pavement. A low-grade reinforced concrete base course and a weak asphaltic finished layer will produce a strong and durable road pavement.

    The weak asphalt may allow some water percolation, but this will not damage the reinforced concrete base course as concrete is resistant to water. The weak concrete wears easily but is protected against contact from tires by the asphaltic layer. The weak reinforced concrete is more rigid than the compacted crushed stone base course layer and is therefore able to distribute loads effectively over a wider area of land. This enables the road to carry more loads. This is necessary at a time when a lot of heavy items are hauled using our roads.

    •Engr. Okonkwo Ph.D is of Department of Civil Engineering, Nnamdi Azikiwe University Awka, Anambra State.

  • Developer dangles affordability, flexible payment carrot

    Lagosians desirous of owning affordable housing in a high brow area can now heave a sigh of relief. Dayola Property & Development Company,  a Lagos-based real estate firm, has unveiled two of its prime properties – Beaufort Park and Heirs Park Residences.

    The properties are behind Novare Lekki Mall, Ajah. The Beaufort Park is a 24-unit premium affordable  homes built for investors and those who desire to enjoy living in this fast-developing area of Lagos.

    They come in three-bedroom apartments with boys quarters that will be finished to taste by the buyers.

    The firm’s Managing Director and Chief Executive Officer, Mr. Dayo Olaiya, said the estate is covered by global Certificate of Occupancy (C of O). He noted that the projects go through certified building consultants from commencement to completion. This, he said, puts the properties in a pole position as meeting and surpassing the required standard.

    Other features in the planned estates include intercom and fire alarms, lawn tennis court, swimming pool, two car park slots per housing unit, water treatment plant, electricity, children’s play ground area, tarred road network and drainage system.

    Olaiya said the price of a unit is N19.99 million, which would revert to N23.99 million once the promo is over. Payment plan is an initial deposit of 12.5 per cent or N2.5 million, while the balance payment is spread across 24 months.

    He called on investors to take advantage of the introductory price, which lasts till September.

    “Real estate is an imperishable asset, increasing in value. If not bought for residential purpose, then buying for commercial purpose is a great long-term investment with medium risks and reasonable increase in value. We can bring your real estate investment dreams to fruition. Our projects are developed to suit and meet the needs of discerning investors”, Olaiya said, adding that Heirs Park Residences Phases 1 & 11 located before the sixth Lekki Roundabout, presents a beautiful place for living.

    Heirs Park Residences Phases 1 & 11, Olaiya explained, comprise  four-bedroom maisonettes en suite, with exquisite finishing in a very serene and secured neighbourhood. Each maisonette boasts of three en suite bedroom on the first floor, one-bedroom en suite on the ground floor and a spacious living room and kitchen area with boys quarters.

    Olaiya said the special offer price per unit in this estate is N55 million, with an initial down payment of 20 per cent or N11 million while the balance is spread across 24 months at zero per cent interest rate.

  • Flexible FX policy needs monitoring, says ICAN chief

    Flexible FX policy needs monitoring, says ICAN chief

    The flexible forex policy instituted by the Central Bank of Nigeria (CBN) needs adequate monitoring for it to achieve its desired objectives, the new President of Institute of Chartered Accountants of Nigeria (ICAN), Titus Soetan has said

    He spoke yesterday during a media luncheon by the institute in Lagos.

    Soetan, who backed the new policy, described it as innovative system that allows the exchange rate to be determined by supply and demand forces.

    He urged the CBN to monitor the policy to serve the purpose of which it was introduced; that is, preventing the free fall of the naira and to stimulate foreign investment.

    “The institute is in support of the introduction of flexible forex policy by the CBN. The policy as a monetary system allows the exchange rate to be determined by supply and demand. However, as a policy, it needs effective and adequate monitoring to serve the purpose for which it is being introduced, that is preventing free fall of the naira,” he said.

    On the economy, he said in the face of dwindling crude oil prices in the global market, every avenue to generate sustainable revenues should be explored.

    “There is an urgent need to reduce the cost of governance, curb financial excesses by public officers and blocking all sources of leakages of revenues in the economy,” he said.

    According to Soetan, government at all levels should be encouraged to adopt transparent policies to reengineer the economy sustainable level.

    “As a professional institute, we urge government at all levels to initiate actions and policies to promote and provide enabling environment for business to operate with ease. The diversification of the economy has become so urgent in the face of global oil price crash on which the country has depended for too long a time,” he added.

    On corruption, he said the judiciary must realise its responsibility in fighting corruption.

    “Without eradicating corruption the government will not make any progress in its developmental efforts. The ICAN appreciates the efforts of the current administration and the Armed forces in fighting terrorism, Boko Haram. We appreciate the gallant effort of the army. It is our hope that every Nigerians will be their brother’s keeper by reporting any threat to the appropriate authority,” he said.

    On the bailout for states, he said: “Bail out to the state is a topical issue with divergent views. You will recollect that the recent announcement is the second within a period of 12 months. There are people who argued that they states are insolvent and deserve no further handout.There are also those who supported it because some of the states do not have Internally Generated Revenues and should be supported.’’ The question is that to what extent is bailout sustainable?”

  • Dangote: we lost N50b to ‘flexible exchange’ policy

    Dangote: we lost N50b to ‘flexible exchange’ policy

    Dangote Group President Aliko Dangote said at the weekend that his company lost N50 billion to the flexible foreign exchange policy.

    The Central Bank of Nigeria (CBN) last week scrapped the dual exchange rate policy, creating a single window for the trade in naira.

    Dangote spoke when Vice President Yemi Osinbajo toured the project sites of Dangote Fertiliser and Dangote Refinery in Lekki, Lagos.

    Dangote said the $161 million his companies bought during that period from the CBN merely reflected the size of his business and did not represent preferential treatment.

    “We have been badly affected like any other company,” he said, arguing that operational costs totalled $100 million each month due to recurring expenses, such as the purchase of parts for cement production and running a fleet of 9,000 trucks.

    “When you are talking about 20 billion dollars worth of projects, what is 161 million? One-hundred-and-sixty-one million dollars is what I need in just six weeks,” he said.

    “This week (last week), the Central Bank removed the peg that has held the naira at the official rate of 197 for the last 16 months, leading to a 30 per cent devaluation as the currency traded freely on the interbank market.”

    Dangote said the decline had pushed up costs. “This devaluation alone, we have lost over 50 billion naira ($176 million),” he said.

    “The gas, which is our main source of power, is priced in dollars. If there is 40 per cent devaluation, your price will go up by 40 per cent. Every single aspect of the production will go up by that percentage,” he said.

    To Osinbajo, the Dangote Fertiliser and Petrochemical projects are capable of assisting in the government’s drive to reduce poverty through generation of foreign exchange.

    He said it was also in line with the Federal Government’s immediate objective of diversifying the economic base of the country as a result of the plummeting of the price of oil, the country’s sole foreign exchange earner.

    Osinbajo was accompanied during the working visit to the Dangote Refinery, Petrochemicals and fertilisers, reputed to be the biggest in Africa when completed, by Lagos State Governor Akinwunmi Ambode, Ministers of Finance (Mrs Kemi Adeosun); Power, Works and Housing (Babatunde Fashola); Solid Minerals Development (Kayode Fayemi) and others. He was amazed at the size of the projects and reiterated the government’s preparedness to provide an enabling environment for businesses to thrive.

    Dangote said the diversification of Nigeria’s economy was long overdue and that one sector that the government can focuses on is agriculture.

    He said his investment in fertilizer production was a sure way the diversification into agriculture could succeed because according to him, it will amount to little if focus is directed to agriculture and fertilisers would be imported.

    “By the time we complete this project, there will be opportunity to take on agriculture and say bye to poverty, because there will be jobs, no sector has more job potential than agriculture,” Dangote added.

    Dangote told the Vice-President that the $12 billion refinery would have a capacity of 650,000 barrels a day. According to him, there will be market for the refined products because only three African countries – South Africa, Egypt and Cote D Ivoire – have functioning refineries.

    On the project, he said: “Mechanical completion will be end of 2018 but we will start producing in 2019.”

    The refinery, petrochemicals and fertiliser in one spot according to Dangote, is the single largest stream in the world. “This site is the biggest site in the world, the refinery is the biggest single refinery in the world, the petrochemicals is 13 times bigger than Eleme petrochemicals while the fertiliser plant will be 10 times bigger than former National Fertiliser company. The project, with the  $2 billion fertiliser unit  was the funded through loans, export credit agencies and our own equity, Dangote said.

  • CIIN: flexible FX policy boosts insurance

    CIIN: flexible FX policy boosts insurance

    The Chartered Insurance Institute of Nigeria (CIIN) yesterday said that the new flexible foreign exchange policy being championed by the Central Bank of Nigeria (CBN) will boost insurance business.

    CIIN Deputy President, Mrs. Funmi Babington-Ashaye disclosed this at a press briefing held in Lagos, said the previous policy regime have dampened the operations and security of the insurance industry.

    She also said that with the economy at the edge of recession and inflation rising daily, many corporate organisations and individuals were already cutting insurance from their needs.

    According to her, a lot of insurance companies were not been able to cede about 80 to 90 per cent of oil and gas and aviation reinsurance premium to overseas reinsurers. Mrs. Babington-Ashaye noted that but for the recent intervention of the new forex regime the inability of Nigerian insurers to cede the large risks abroad was a disaster waiting to happen.

    She said: “Usually insurance companies keep a very small proportion of large risks like oil and gas, aviation premium in this market but many of them were not been able to cede reinsurance premium to overseas reinsurers. With the new policy, we believe that forex will be available at any time to any country or individual at the rate determined by demand and supply and it should be able to resolve this problem.

    “In addition, claims have been mounting and we had to pay based on adjusted figure. The prices were going up, big claims were coming in and it was becoming an issue for us.

    CIIN President, Isioma Chukwuma, said the present economic situation of the country has hindered the commencement of construction works on the institute’s Victoria Island property.

    She said the industry will not allow the poor economic situation to deter operators from making progress, adding that the Institute has secured all relevant documents and government permits for the continuation of work at the site.

  • Flexible forex: marketers strategise for growth

    Fuel marketers are leveraging on their relationship with refineries abroad to make the best of the flexible foreign exchange (forex) regime, which implementation began last Monday.

    It was gathered that the marketers have been discussing with refineries’ owners overseas to ensure efficient fuel supply, with a gurantee for payment.

    The National President, Independent Petroleum Marketers Association of Nigeria (IPMAN), Chief Chinedu Okoronkwo, said marketers will leverage on their contacts,  relationships with owners of refineries abroad, among  other factors, to buy fuel since the government has simplified the process of accessing forex.

    He said some marketers have collaborations with foreign refineries, adding that such marketers would rely on the partnership to import fuel into the country. He said marketers that have their own jetties would have unimpeded access to fuel, while those that do not have jetties would have the opportunity.

    Okoronkwo said that indices such as good assets, relationship and confidence, are what marketers need to make the best of opportunities provided by the new forex policy. He said marketers will access forex at relatively cheaper rates, import fuel, sell it, make gains and fresh purchases, and instill confidence in the minds of firms that sell fuel abroad.

    “Marketers will benefit greatly from the forex policy. The reason is because the flexible forex policy would provide them with the opportunity to play better in the industry. The policy would enable marketers to access forex at relatively cheaper rates, import and sell fuel, make gains and fresh purchase, and instill confidence in the minds of firms that are selling fuel abroad. Business thrives on confidence between two parties or more. Through the policy, marketers are sure of getting opportunities to buy forex. As a result of this, marketers would be bringing fuel into the country. Once marketers are getting returns on investment (RoI), they would not hesitate to buy more fuel,  a development, which would go a long way in building confidence in the owners of refineries abroad.’’

    He said marketers would not run out of fuel during the new regime, assuring that there would not be fuel scarcity again. Marketers, Okoronkwo said, would be able to project how, when and where to buy dollars whenever they discover that the currency is scarce in the market, stressing that the issue would enable them to do a comparative analysis of happenings in the oil industry for growth.

     

  • ‘What flexible forex policy means to manufacturers, investors’

    The Central Bank of Nigeria (CBN’s) decision to adopt  flexible foreign  exchange (forex) rate  has been long-awaited by local and international investors, analyst at Eczellon Capital Limited, Mustapha Suberu, said yesterday.

    According to him, the policy allows only one single market structure where rates are determined by market forces, adding that it is expected to boost investors’ confidence and get more dollars into the system.

    The policy, which was unveiled yesterday by the CBN Governor, Godwin Emefiele, would not only increase the volume of dollar in the system, but give government the desired confidence to approach the issue of $1 billion Eurobonds in August.

    Explaining what the new policy entails, Suberu said the interbank market will from Monday, become the only market where rates for the naira and dollar would be determined. He said the naira three-month forward rate currently trades at N333 to dollar, and that the rate to be adopted would not be too far from the forward rate.

    Going forward, he said the naira/dollar rate would be determined by the forces of demand and supply, adding that the policy would help government source debt from the international market because investors would be more confident about the state of the local currency against the dollar.

    Suberu said the manufacturing sector would no longer access forex at the official rate, a practice that would likely raise the prices of goods.

    Also, Nigeria is expected to source for more foreign loans  to take advantage of lower interest rates and allow local banks to lend to small businesses.

    The Federal Government said it wants to switch its debt mix so that 40 per cent of loans would come from abroad, compared with 16 per cent that obtains now, and extend its debt maturity profile.

    It plans to borrow as much as $10 billion from debt markets, with about half of that coming from foreign sources, to help fund a budget deficit worsened by the slump in oil prices that has slashed revenues and weakened the currency.

    President, Association of Bureau De  Change Operators of Nigeria (ABCON), Alhaji Aminu  Gwadabe,  said the policy  is skewed in favour of only a few operators in the forex market. “To me, instead of deepening the market, the policy will lead to further shrinking in the volume of dollar available in the market,” he said.