Question

For water bound macadam roads in places of heavy rainfall, the recommended value of camber is ____

• A. 1 in 36
• B. 1 in 30
• C. 1 in 48
• D. 1 in 60

Hint:

Typical IRC camber values: \[ \boxed{ \begin{aligned} \text{Cement Concrete} &\approx 1:60\\ \text{Bituminous} &\approx 1:50\\ \text{WBM} &\approx 1:36 \end{aligned} } \]

Answer 1

The Correct Option is A

Step 1: Recall why camber is provided.
Camber is the transverse slope given to a road surface so that rainwater drains off quickly instead of standing or soaking into the pavement.
Step 2: Consider why WBM roads need extra attention.
Water bound macadam is a more pervious, rougher surface compared to a bituminous or concrete surface, so water can soak in and weaken the base if it isn't shed fast enough, especially where rainfall is heavy.
Step 3: Recall the IRC recommendation.
For WBM roads in regions of heavy rainfall, IRC recommends a comparatively steep camber to clear water quickly.
\[ \boxed{1\ \text{in}\ 36} \]