The Akwanga road project included seven reinforced and prestressed concrete bridges, with a total bridge length of 250 m. Two of these are prestressed concrete (PSC) bridges incorporating 30 m spans.
Key facts
- Bridges: 7 reinforced and prestressed concrete bridges, 250 m in total length
- Prestressed bridges: 2 PSC bridges incorporating 30 m spans
- Structural concrete: 36,802 m³ (bridges, box culverts, retaining structures)
- PSC girder concrete: 605 m³ precast / prestressed
- Reinforcement steel: 2,396 tonnes
- Bearings and joints: 90 elastomeric bearings, 104 m of expansion joints
Designed in-house
ICCO carried out the structural design of the bridges and culverts as part of the contract's design and engineering scope. It also prepared the drawings, calculations and construction documentation used on site.
Handling design and construction together means the people who build each bridge work from drawings made by the same team, which helps problems get resolved quickly on site.
Concrete and steel
Building the bridges, box culverts and retaining structures called for large volumes of materials:
| Item | Executed quantity |
|---|---|
| Structural concrete – bridges, box culverts and retaining structures | 36,802 m³ |
| Precast / prestressed concrete for PSC bridge girders | 605 m³ |
| Reinforcement steel for structural works | 2,396 tonnes |
Reinforcement steel gives concrete the strength to resist bending and cracking under load. In the PSC girders, the steel is tensioned so that the concrete is held in compression, allowing longer spans.
Why prestressed spans matter
Prestressed girders can span 30 m with fewer supports in the waterway. Fewer piers mean less obstruction to water flow, which reduces the risk of scour around the foundations during heavy rain.
Scour is the washing away of soil around a foundation by fast-moving water. It is one of the main causes of bridge damage in flood conditions, so a design that puts fewer piers in the channel helps the structure last.
Bearings and joints
ICCO installed 90 elastomeric bridge bearings and 104 m of bridge expansion joints.
| Item | Executed quantity |
|---|---|
| Elastomeric bridge bearings | 90 |
| Bridge expansion joints | 104 m |
Bearings sit between the deck and its supports, carrying the load while letting the deck move slightly. Expansion joints allow the deck to grow and shrink with temperature without damaging the road surface.
Certified with the full 54 km
The bridges were completed as part of the full 54 km scope. The Nasarawa State Urban Development Board certified the works complete in April 2022, confirming they met the approved drawings and technical specifications.
More on the Akwanga 54 km road
This article is part of a five-part series on the project:
- ICCO Completes 54 km Road Project in Akwanga LGA, Nasarawa – the scope, value, timeline and completion of the project.
- Moving 2.5 Million m³: Earthworks Behind Akwanga's 54 km Road – the earthworks and layered pavement.
- Drainage and Culverts Keep Akwanga's New Road Dry – the drains and 72 culverts that keep water off the road.
- Akwanga's 54 km Road Built for Future Utilities and Safer Travel – the HDPE service ducts and flexbeam guardrails.
Frequently asked questions
How many bridges are on the Akwanga 54 km road?
There are seven reinforced and prestressed concrete bridges with a total bridge length of 250 m. Two of them are prestressed concrete (PSC) bridges incorporating 30 m spans.
Who designed the bridges?
ICCO carried out the structural design of the bridges and culverts as part of the contract, and prepared the drawings, calculations and construction documentation.
Why use prestressed girders?
Prestressed girders can span 30 m with fewer supports in the waterway. Fewer piers mean less obstruction to water flow, which reduces the risk of scour around the foundations.
What do bearings and expansion joints do?
Bearings carry the deck's load while letting it move slightly. Expansion joints allow the deck to grow and shrink with temperature without damaging the road surface.
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