Question

What is the purpose of expansion joints in a bridge?

Answer 1

Expansion joints are one kind of joints used in bridges. They are made to accommodate the expansion of solid which takes place when a solid is heated. This condition occurs in summers when the temperature is very high. If the joints are made to fit the size of the bolt, they will undergo stress during summers which will ultimately lead to failure of the structure.

Complete step-by-step solution
Expansion joints have great importance to the life of the bridge which has to be installed properly to maintain and function properly. These expansion joints are designed to allow continuous traffic between the structures irrespective of the effect of movement, temperature, shrinkage and climatic conditions. These joints consist of some metal bellows mixture of rubber, plastic and other minerals.
These expansion joints are used to avoid the thermal expansion which may occur due to high temperature during hot days. They are designed in such a way that it can accommodate deformation by external load and variations. These joints should be in the range of 8 to 12 feet apart. Without the expansion joints the resonant frequency build up cannot be avoided which can amplify the swaying of bridges. This can be very dangerous and bridges can collapse.

This is the role and purpose of expansion joints in bridges.

Note: The expansion joints are placed before putting the concrete. They allow the slab to move without putting any stress. They are also used in building slabs, pool decks and also in between slabs.