What is Telford Road Construction

Road construction and paving

Chaussing and paving were the given methods until the 1920s to pave artificial roads and to create a surface that was as flat as possible for traffic.

The road construction permits go back to the French road construction engineer Pierre Marie Jerome Trésaguet (1716 - 1796). From 1764 he ordered a new structure for the streets: a packing layer of 15-20 cm high, pyramid-shaped hewn stones, in the interstices of which smaller stones were hammered ('twisted') with hammers so that they sat firmly. This was followed by top layers of very hard, small stones (gravel) and gravel. In the case of the poorly stable subsurface, Trésaguet had stone slabs around 8 cm thick laid under the packing layer in order to evenly distribute the pressure from the wagon wheels.

ViaStoria collection; Source: Artur Speck, Der Kunsstraßenbau, Berlin 1950, p. 22

Thoma Telford (1757 - 1834) adopted the French basic principles for road construction in England. On behalf of the government in Scotland, he built around 1,500 km of roads and 1,117 bridges within 18 years. He became famous for building the road from Shrewsbury to Olympus in North Wales. It heals a packing layer of 18 high and 10 cm wide stones placed close together. To compensate for this, Telford had a 15 cm thick layer of stone laid over it, which he completed with a top layer of broken stones and gravel max. 6 cm in size.

At the same time, John Loudon McAdam (1756 - 1836) was also involved in English road construction. In 1816 he was appointed administrator of some 300 km of roads for a road association in Bristol. He knew about the economic benefits of well-developed roads, but thought about cheaper construction methods. His observation that the quality of a driveway is primarily determined by the top layer, led him to forego the packing layer entirely. In the favorable, frost-free climate of West England, the careful installation of several layers of pure limestone gravel with a grain size of 25 mm was sufficient. The functioning drainage of the stone carriageway was decisive; she was not allowed to have a banquet and had to be regularly maintained very carefully. In 1823 a parliamentary commission recommended this type of construction as the standard. McAdam was appointed inspector general of the roads in the London area and has since been regarded as the 'forefather' of modern road construction. Even today, the layered construction of asphalt roads is called 'macadam construction'. see tar and asphalt roads).

In the countries of Europe mostly artificial roads with packing layers were made, e.g. B. also in Saxony. In contrast to the French construction method, however, flat stones were laid on the subgrade, which are protected from slipping into the ditch by side curbs. The roadway consisted of sharp-edged broken stones of different sizes, gravel and sand.

ViaStoria collection; Source: Artur Speck, Der Kunsstraßenbau, Berlin 1950, p. 22