Cross Sectional Elements Questions and Answers

Answer: A

For cement concrete roads in areas with heavy rainfall, the recommended camber is 1 in 50, which is steeper than the 1 in 60 sometimes allowed in light rain. A cross-slope of this order drains the surface quickly, while a flatter one lets water stand. The values of 1 in 40, 1 in 33 and 1 in 25 are the cambers that are used for lower types of surface such as gravel, WBM and earth roads, which need a steeper slope because they are more permeable and rougher.

Answer: B

The maximum camber for an earth road is 1 in 25.

Camber depends on the surface and the rainfall: the more pervious and rough the surface, the steeper the camber needed to shed water. IRC recommends 3 to 4 percent for earth roads, the steepest of all surfaces, so the maximum is 4 percent, or 1 in 25.

1 in 40 (2.5 percent) suits a paved or gravel surface, and 1 in 20 (5 percent) and 1 in 16.7 (6 percent) are steeper than the recommended range and would cause erosion of the road surface.

Answer: B

The convexity is called the Camber.

Camber (cross slope) is the slope given to the carriageway from the crown to the edges, so that rainwater drains off the surface quickly. It is usually shaped as two straight slopes or a parabola.

Gradient is the longitudinal slope along the road, kerbs are the raised edging along the pavement, and a vertical curve joins two different gradients.