Inexpensive new instruments test building sealants under real-world conditions

Apr 05, 2011

Sealants, like weather stripping, are what separates the inside from the outside of a building, byproviding a barrier that prevents water from seeping in, for example, or heat from leaking out. The challenge, says research chemist Christopher White of the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland, is predicting when they will fail.

Current methods test sealants statically, by placing them outdoors for long periods of time, to measure their resistance to the elements. The problem, says White, is that under normal conditions, sealants are also affected by constant movement: the temperature-induced expansion and contraction of the different kinds ofmaterials they seal together—such as glass, in a window, and steel, in the window and building frame. "When you put sealant on a building, it is because the glass window and steel frame expand and contract at different rates with changes in temperature," he explains. "The sealant needs to be able to seal this gap, as it changes." This creates fatigue in the sealant, eventually causing it to crack and fail.

Using simple materials that can largely be purchased from a hardware store—including PVC pipe, wood, steel supporting frames, and toilet flanges—White and his colleagues have developed the first instruments to test sealants under real-world conditions, while monitoring their displacement and load with sensors and tracking environmental conditions with a station. "This new device—which is very inexpensive—induces movement that is very similar to what a sealant would see in the actual application, in a ," he says.

The designs of the two devices—one that puts in tension and one that puts them in compression when cold—have been passed along to an industrial consortium of sealant manufacturers working with NIST. "Two companies have actually built and are using them for sealant testing," says White.

Explore further: Switzerland to test drone postal deliveries

More information: The paper, "Design, Fabrication and Implementation of Thermally Driven Devices for Building Joint Sealants," by Christopher White, Kar Tean Tan, Emmet O'Brien, Don Huntson, and Joannie Chin, appears in the Review of Scientific Instruments.

Related Stories

FDA OKs new adhesive to treat burn victims

Mar 20, 2008

The U.S. Food and Drug Administration approved a medical adhesive -- a fibrin sealant called Artiss -- for use in attaching skin grafts to burn patients.

Recommended for you

Intellectual property in 3D printing

Apr 16, 2015

The implications of intellectual property in 3D printing have been outlined in two documents created for the UK government by Bournemouth University's Dinusha Mendis and Davide Secchi, and Phil Reeves of Econolyst Ltd.

World-record electric motor for aircraft

Apr 16, 2015

Siemens researchers have developed a new type of electric motor that, with a weight of just 50 kilograms, delivers a continuous output of about 260 kilowatts – five times more than comparable drive systems. ...

Space open for business, says Electron launch system CEO

Apr 15, 2015

Space, like business, is all about time and money, said Peter Beck, CEO of Rocket Lab, a US company with a New Zealand subsidiary. The problem, he added, is that, in cost and time, space has remained an incredibly ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.