Thermal Linear Expansion of Bridge

Expansion joint is the joint between the two parts of the building, which is necessary for reasons of length changes caused by the type of fabric or temperature change. This way we prevent the adverse disturbances that may arise from volume changes. The width of the expansion joint depends on the length of the dilatation section, on the environment and on the temperature.

The model shows a bridge that includes an expansion joint. When choosing higher temperature the heat taken in from the surroundings will raise the internal energy of the material, from which the bridge is made. Particles of the material will begin to move with greater speed around the equilibrium positions in larger distances. The volume will start to increase and extend the bridge. To avoid permanent destruction the expansion joint is installed between the bridge and both ends of the roadway. As it has some free space, the bridge may extend and if the temperature is lowered, it can shorten again.