Expansion joints are always considered as the most vital components of a total piping system, bridges and several other structures. They are broadly used in various industries where thermal expansion or contraction happens in the piping system.
What is an expansion joint?
An expansion joint is an assembly specially designed for holding parts together and absorbing the temperature-induced contraction as well as expansion of the building materials with safety. It also absorb vibration and allow movement because of the seismic activities or ground settlement. It is found in between the sections of piping systems, bridges, buildings, railways tracks, ships, sidewalks and many other structures. The concrete slabs, buildings faces and pipelines contract and expand because of cooling and warming from the seasonal vibrations or some other sources. Without expansion joint gaps the structure can crack under the stresses induced.
It is used in the bridges are specially designed for allowing constant traffic in between the structures and accommodate shrinkage, temperature and movement variations on composite, concrete and steel structures. These joints stop bridges from bending in extreme conditions.
Why are expansion joints used?
It is used as a transition between the two surfaces. The rubber joints are made of rubber and silicone to fill the gap or fulfil the seal. It can take shapes because they need to absorb the movements. If there is any movement in between two surfaces these joints can be effective and can maintain their position & seal. It is very important as these are custom designed. They are extruded based particularly on their purpose and applications. Metallic expansion joints are the most common ones to be used.
What are the benefits of installing expansion joints?
Let us learn in precise detail regarding the benefits of expansion joints:
a) Requirement for big buildings –
Almost every big building has solid joints. When the high temperature inserts the materials be it iron or concrete, the material expands greatly. It is evident that with the expansion, some pressure will get exerted over the concrete material. In concrete, there is no flexibility, so cracks begin to appear in concerning time but installing joints for the buildings can guarantee that those cracks on high heat expansion forms are compressed properly.
b) Offers security from the thermal expansions
In summer, the temperature rises and causes a great deal of expansion because of it and makes at least centimetres of movement because of the expansion process. This millimetre of movement also causes thermal expansion if it is devoid of security padding in expansion joint form, then cracks usually appear and this can cause dangerous accidents. Usage of proper joints can avoid cracks and the buildings can last for more years.
What to take care of while installing expansion joints?
The expansion gaps in your slabs and walls can be easily made watertight if needed by installing sealant and a water bar. While installation, the expansion joints in structures have to be carefully located. They can be made waterproof by offering capping at the joints. Take care of the internal finishes at the places where these joints are situated.
What are the different kinds of expansion joints?
1) Single unrestrained- The single unrestrained metallic joints are one of the simplest joints and come with only one bellow section along with end connections. This kind of expansion joint needs control of bordering piping concerning guiding & anchors.
2) Universal expansion joints
This expansion joint consists of two “bellow” sections linked through a pipe section located at the centre. Universal joints permit huge amounts of lateral deflection. This expansion joint allows both angular and axial movements along with lateral movement.
3) Single tied expansion joints-
The single joints are similar to single unrestrained expansion joints but this is offered with the tie rods.
4) Tied universal expansion joints
It looks like the universal joints but come with tie rods.
5) Externally pressurized expansion joints
The line pressure externally acts on bellows through the pressure chamber. It allows many convolutions used for big axial movements with no instability of bellows. Another benefit of the pressurised expansion joints is – self-draining convolutions when standing media is an issue.
So we hope you have understood the importance of joints in your structures that are good at absorbing shocks and vibrations. It greatly compensate for the misalignment. Metallic joints are used in various kinds of applications. To avoid cracks under stress, expansion joints are compulsory for bridges and several other service.