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<< Click to Display Table of Contents >> Drainage |
  
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<< Click to Display Table of Contents >> Drainage |
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The movement of fines resulting from erosion and the formation of voids and faulting is greatly enhanced by the presence of water. This is called pumping. Pumping can only occur where deflections or relative vertical movements at joints or cracks are high and where water is present. Water can enter the pavement through unsealed joints or cracks or through poorly performing side drains, especially in high-rainfall areas.
The drainage factor depicts the road characteristics in terms of the risk of water be present in the road pavement and it is a function of the weather and environment:
Description of the pavement |
Annual rainfall, mm |
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< 400 |
400 - 800 |
> 800 |
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Pavements with concrete shoulders |
Unsealed and poorly maintained joint seals |
6 |
4 |
2 |
Well maintained joint seals |
10 |
6 |
4 |
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Pavements with flexible shoulders |
Unsealed and poorly maintained joint seals |
4 |
2 |
1 |
Well maintained joint seals |
6 |
4 |
2 |
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