In our daily life, we pay special attention to deal with thermal expansion and contraction of solids in various construction projects. In order to avoid the harmful effects of thermal expansion and contraction of solids, the techniques used in different projects are as follows:

Expansion Gaps in Concrete Roads

In hot summer, the concrete used to build roads expands. If no space is provided for its expansion, the road surface cracks. To avoid such damage, small gaps are left after every few meters in the Constitution of concrete roads of footpaths.

 thermal expansion

Railway Tracks

Two sections of a railway track are not welded together. Instead they are laid with gaps between them. This allows expansion and contraction of rails during summer and winter seasons. If there are no gaps in the sections of railway tracks, they may DE-shape due to expansion in summer.

expansion gap in railway

expansion gap in railway

De-shaped railway track

De-shaped railway track

Expansion of Bridges

Iron girders are used in the construction of bridges. One end of each girder is fixed while the other end rests on the rollers. A gap is also left at this end. In this way the girder can move forward or backward during expansion or contraction. If there is no expansion gap, bridges may get damaged.

rollers in bridges

Overhead Power Lines and Telephone Wires

Overhead telephone and electricity wires installed on poles expand during hot weather and contract in cold weather. The wires between two poles are given a certain amount of sag so that they may contract in winter without snapping.

Overhead Power Lines

Overhead Power Lines

Large Bends in Pipes

The pipes through which hot or cold liquid or gas flows are often given bends so that they may expand or contract without cracking.

Pipes carrying hot or cold liquids

Pipes carrying hot or cold liquids