Kerbing and channel

A worked example

This is the job the page opens with, already worked out. Change any figure above and the answer changes with it.

The job

Length of the run

200 m

Kerb unit length

1 000 mm

Bedding width

300 mm

Bedding thickness

100 mm

Haunch width

150 mm

Haunch height

150 mm

Breakages and waste

5 %

Concrete mix

1:3:6, foundations and footings, about 15 MPa

The answer

210units  ·  Kerb units

Run at 1 000 mm per unit

200

Bedding concrete

6 m³

Haunching concrete

2.25 m³

Concrete total, with 5%

8.662 m³

Cement, 50 kg bags

38.44 bags

Sand

4.002 m³

Stone

8.004 m³

The working

Bedding 300 × 100 mm = 0.0300 m² per metre.
Haunch is a triangle, ½ × 150 × 150 mm = 0.0112 m² per metre.

What it assumes

• The haunch is taken as a triangle against the back of the kerb. A square haunch is double this, so change the height and width to suit your detail.
• One side only. Kerbs both sides of a road means running it twice, or doubling the length.
• No allowance for radius kerbs, drop kerbs, or the extra concrete at an inlet.