Featured Research

from universities, journals, and other organizations

Baked Slug: New Method To Test Fireproofing Material

Date:
October 10, 2008
Source:
National Institute of Standards and Technology
Summary:
Researchers have developed a technique for measuring a key thermal property of fire-resistive materials at high temperatures. The measurement technique has already been adopted commercially and incorporated into a national standard.

Microtomography image of the pore structure of a fireproofing material. The different colors identify different individual pores within the material, whose size and shape have a large influence on the thermal conductivity of the material at high temperatures.
Credit: NIST

In a high-temperature blaze, how well does a fireproofing material shield a building’s important steel structures from heat? Answering this question has been surprisingly difficult, but it is important information for builders selecting high-performance fire-resistive materials and for scientists conducting computer simulations that investigate fires.

Related Articles


Now, researchers at the National Institute of Standards and Technology (NIST) and their colleagues have developed a technique for measuring a key thermal property of fire-resistive materials at high temperatures. The measurement technique has already been adopted commercially and incorporated into a national standard.*

In creating computer simulations to study the collapses of the World Trade Center buildings on Sept. 11, 2001, NIST researchers needed to know important properties of the fireproofing materials that protected structural steel columns. One key property was the thermal conductivity of the material: How quickly does heat transfer through it? Thermal insulation has a low thermal conductivity and metals have a high thermal conductivity.

There are long-established methods for measuring thermal conductivity under ambient conditions, but a material’s thermal conductivity can change markedly when it is subjected to extremely high temperatures that cause important chemical and structural changes. Traditional methods for measuring thermal conductivity at high temperatures have not been adequate. They have relied on “hot wire” techniques, which use wire probes to measure heat flow through a wire surrounded by the material of interest. At sufficiently elevated temperatures, the material can separate from the wire preventing the measurement of the thermal conductivity in a highly heated material.

NIST’s Dale Bentz and his colleagues developed a “slug calorimeter” technique for obtaining the thermal conductivity information at elevated temperatures. In this technique, they use a thin square slab of steel material known as a slug and sandwich it between slabs of the fireproofing material of interest. Guard insulation surrounds the sides of the sample so that heat flows preferentially through the sandwich when it is placed in a high-temperature furnace. Three temperature probes inserted into the steel slug measure the heat flowing to the steel. Combining this data with the known heat capacities and densities of the steel slug and the fire-resistive material, the researchers can determine the material’s thermal conductivity at various temperatures.

Following the successful demonstration of this method at NIST, two large U.S. testing labs have worked with NIST to develop their own in-house slug calorimeters as a testing service to their clients, and a third U.S. company recently introduced a commercial version of a slug calorimeter. ASTM International (formerly the American Society for Testing and Materials) has published a standard (ASTM E 2584) detailing how to conduct thermal conductivity measurements with the new method. Possible applications beyond steel fireproofing material, Bentz says, involve measuring the thermal conductivity of wood-based materials, as well as the insulating materials used to protect spacecraft such as the Space Shuttle.

* D.P. Bentz, D. Flynn, J.H. Kim and R.R. Zarr. Fire Materials, 2006; 30:257-270; and ASTM Standard E 2584-07, “Standard Practice for Thermal Conductivity of Materials.”


Story Source:

The above story is based on materials provided by National Institute of Standards and Technology. Note: Materials may be edited for content and length.


Cite This Page:

National Institute of Standards and Technology. "Baked Slug: New Method To Test Fireproofing Material." ScienceDaily. ScienceDaily, 10 October 2008. <www.sciencedaily.com/releases/2008/10/081002172144.htm>.
National Institute of Standards and Technology. (2008, October 10). Baked Slug: New Method To Test Fireproofing Material. ScienceDaily. Retrieved January 29, 2015 from www.sciencedaily.com/releases/2008/10/081002172144.htm
National Institute of Standards and Technology. "Baked Slug: New Method To Test Fireproofing Material." ScienceDaily. www.sciencedaily.com/releases/2008/10/081002172144.htm (accessed January 29, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Thursday, January 29, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

'Brand Blocker' Glasses Blur Ads in Real Time

'Brand Blocker' Glasses Blur Ads in Real Time

Buzz60 (Jan. 28, 2015) — A team of college students design and build a pair of goggles that will obscure any corporate branding from your field of vision. Jen Markham (@jenmarkham) has the story. Video provided by Buzz60
Powered by NewsLook.com
Amplifying Tiny Movements to Visualize the Invisible

Amplifying Tiny Movements to Visualize the Invisible

Reuters - Innovations Video Online (Jan. 28, 2015) — A new video recording method that amplifies seemingly invisible motion could lead to a touch-free vital signs monitor, and offer a new tool for engineers to gauge stresses on bridges and tunnels in real time. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Boeing's Profit Soars

Boeing's Profit Soars

Reuters - Business Video Online (Jan. 28, 2015) — Boeing delivered more commercial planes, especially 737s and 787s, fueling profit. But it issued a mixed outlook. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Robot Replacements for Foxconn's Workers

Robot Replacements for Foxconn's Workers

Reuters - Business Video Online (Jan. 28, 2015) — Foxconn parent Hon Hai Precision Industry is looking to automation to keep productivity up without the rising costs of human labor. Meg Teckman reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins