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.
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 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.
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.
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.