Effects of excessive camber on pavements: which of the following may occur if the camber (crossfall) provided is unnecessarily high?
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Adeterioration of central portion
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Bslip of the speedy vehicles towards the edges
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Cerosion of the berms
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Dall the above.
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E
Answer
Correct Answer: all the above.
Explanation
Introduction / Context:Camber provides crossfall for surface drainage. While necessary, excessive camber can produce undesirable structural and operational effects on the pavement and adjacent shoulders (berms).
Given Data / Assumptions:
- Pavement has a camber larger than recommended for the surface type and rainfall.
- Vehicles operate at representative speeds.
- Berms and drainage are typical of rural highways.
Concept / Approach:Too large a crossfall pushes water and traffic laterally too aggressively. Water concentrates at edges, accelerating erosion; vehicles experience lateral component of gravity that can cause outward skidding; the crown region carries more compression and may ravel or crack due to thin water film movement.
Step-by-Step Solution:
Identify issues caused by excessive crossfall: poor ride, instability, edge distress.Relate hydraulics: faster runoff near edges erodes berms and weakens shoulders.Relate traffic dynamics: lateral component encourages outward slip at speed, especially on low-friction surfaces.Verification / Alternative check:Field inspections correlate over-cambered sections with edge raveling, berm gullying, and centerline distress due to uneven load distribution and drainage patterns.
Why Other Options Are Wrong:Each of (a), (b), and (c) are valid individual consequences; therefore “all the above” best captures the full effect set.
Common Pitfalls:Using a “one size fits all” camber; not adjusting camber for surface type (e.g., CC vs bituminous) and rainfall intensity.
Final Answer:all the above.