Expansion joints, also known as movement joints, are assemblies designed to safely absorb the expansion and contraction of building materials induced by temperature, moisture, seismic movements, vibrations, and so on, as well as hold them together. These are commonly used between sections in virtually every structure, such as roads, sidewalks, buildings, bridges, piping systems, railway tracks, ships, etc. Expansion joints come in many different options, from basic single expansion joints to more sophisticated pressure-balanced joints, but they can also vary in terms of the material they are made of. Read on to learn the most common materials used in expansion joints and their unique benefits and potential drawbacks, if any.
1. Metal alloys
Metal is a popular material choice for expansion joints due to its high strength, durability, and capacity to withstand enormous stress. Stainless steel and aluminium are among the most common alloys used for expansion joint materials, thanks to their low coefficient of thermal expansion. This means they do not expand or contract much when exposed to heat or cold, making them ideal for applications where the temperature can vary significantly. But despite their excellent performance, metal expansion joints remain prone to corrosion, which can lead to all manner of issues over time.
2. Polymer-based materials
Polymer-based expansion joints are the next best alternative for applications that require great strength and a low coefficient of thermal expansion without running the risk of corrosion. Apart from these advantages, expansion joints made of polymer are also easy to work with and more affordable than metal ones. Thus, polymer expansion joints work great in systems that must remain stable under high temperatures, provided they are compatible with their other components.
3. Rubber-based materials
Rubber is another great choice for expansion joints due to its durability, flexibility, and high-stress tolerance. They also have low thermal conductivity, so they do not heat up as quickly as metal materials under hot temperatures. Lastly, rubber-based joints are quieter than other materials, making them a good choice for residential and commercial settings.
That said, rubber naturally gets brittle and deforms when exposed to temperatures that exceed the limits specified by the manufacturer. So, it is important to be careful when choosing rubber-based expansion joints and to check if their temperature limits are well within your expected thresholds.
Epoxy is an adhesive usually used to connect materials but is also a popular choice for expansion joints, typically for relieving stress and tension in structures. Epoxy-based expansion joints are ideal for enabling walls, roofs, and flooring to handle a lot of stress and expand and contract without suffering damage. Other benefits of epoxy include their low viscosity, allowing for ease of use, quick application times, and wide range of application temperatures, which means they can perform well in different environments.
Fabric expansion joints are highly flexible materials with excellent strength retention and chemical resistance. They can compensate for large movements in several directions, including axial, lateral, angular, and torsion, making them an ideal solution for many industrial applications. Furthermore, they support temperature- and vibration-induced expansion of building components. However, they are not as durable and will require periodic maintenance and replacements and are only suitable for applications involving low temperatures.
Expansion joints vary in type and the materials they are made of, with the latter offering unique pros and cons. Thus, it is vital not to neglect material choices and factor them into your specific application and requirements to choose the right expansion joint solution for your needs.
If you need quality stainless steel, rubber, or fabric expansion joints for your project, Pharmchem Engineering has everything you need. Although we are a reliable expansion joint supplier in Singapore, we offer many other cost-effective and industrial engineering parts and components, such as hoses, anti-vibration mounts, dry disconnect couplings, and more. Contact us today to learn more about our industrial engineering supplies and customisation solutions!