Expansion joint design is one of the most important developments in modern construction. While most tend to think of expansion joints in cars, they can be found anywhere, from railroads to spacecraft. The main point in understanding the expansion joint design is to understand the question: how can we accommodate design to incorporate the problem of environmental resistance?
Once one understands this fundamental question, the purpose of expansion joint design becomes clear, making it easier to choose the appropriate type of expansion joint to be used in various specific projects.
How Expansion Joints Are Made
Expansion joints, depending on their size, are created through typical industrial processes but with high-resistance metals. The reason for this is that expansion joints operate on the same principles as, but are not technically, springs: they are meant to withstand and sustain pressure, but to a far less degree, restore the original balance after pressure is applied. In this they are basically designed with the purpose of keeping structural integrity in mind.
Because of this, most expansion joints are thought of as a series of metal bellows, though this is not always the case. Expansion joints on railroads, for example, are flat joints designed with space to handle a certain level of environmental pressure. In fact, expansion joints can even be used with concrete in street structures as well as parking spaces!
Expansion joints are made with a wide variety of materials. For most industrial uses, some variation of tempered stainless steel is used, but depending on the application, expansion joints can be made in copper or even high-grade rubber. However, for the purpose of business applications, steel alloy is almost always used. In cases where additional environmental pressure may present a problem, certain alloys can withstand a far higher level of heat.
How Expansion Joints are Used
In a large number of cases, expansion joints in industrial applications are used internally; that is, they’re used to make adjustments for changes in an internal process. Because of this, most expansion joints are similar to pipe joints, accounting for the addition of pressure to the system through the physical process. These joints can either be straight joints, or curved at the angle needed for the particular application in question.
While there are a variety of standard expansion joints, due to the unique nature of industrial application (which can not only affect the type of joint, but the number used) many expansion joints are designed on the basis of a specific need for the application. An experienced engineer with the right amount of experience in such applications can usually determine whether a specific joint will need to be created or a more standard size can be used.
By making sure to take the time to see where your applications may have a potential weakness due to internal or external pressure, you may find that expansion joints will be necessary to efficiently withstand problems with pressure due to environment or by-products of the process itself.