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 December 21, 2014 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 December 21, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Sunday, December 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Building Google Into Cars

Building Google Into Cars

Reuters - Business Video Online (Dec. 19, 2014) — Google's next Android version could become the standard that'll power your vehicle's entertainment and navigation features, Reuters has learned. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
AP Review: Nikon D750 and GoPro Hero 4

AP Review: Nikon D750 and GoPro Hero 4

AP (Dec. 19, 2014) — What to buy an experienced photographer or video shooter? There is some strong gear on the market from Nikon and GoPro. The AP's Ron Harris takes a closer look. (Dec. 19) Video provided by AP
Powered by NewsLook.com
Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Buzz60 (Dec. 19, 2014) — A double-amputee makes history by becoming the first person to wear and operate two prosthetic arms using only his mind. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) — The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary 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