Page 9 - Lecture Notes DCC3113
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Gravel
Excavated
road material
Large stone
foundation
Figure 1-4: John Metcalf Road
Telford roads
Thomas Telford was Scottish road engineer and founder of the institution of civil engineers. He used big
size stones in foundation wearing from 7.5 – 25 cm to develop a firm base. Road was designed with flat
formation, subbase and camber.
20 mm max size
gravel and broken stone
50 mm max size
Knapped top
75 mm
Flat Formation
150 mm
Figure 1-5: Telford Road
John Macadam road
John Macadam, for the first time put forward entirely new concept of road construction in 1826.
He was a Scottish engineer and was surveyor general of roads in England. He designed road with
cambered formation and small angular aggregate as road material.
75 mm broken stone
20 mm broken stone
Cambered Formation
Figure 1-6: McAdam pavement
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