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Re: GSBN:First ASTM E-119 Full Scale Fire Test with Hose Stream Test - PASSED!

At 5:54 PM -0400 7/19/06, strawnet@...:

A few details... in the first twenty minutes or so we saw cracks develop in the stucco on the heated side.

For comparison, the project manager at the lab told me that stucco typically cracks in the first 10 minutes or so. We didn't see any cracks until about 20 minutes.

The temperature on the unheated side of the wall reached 166¡F for the highest reading (at one of the upper thermocouples) but that reading dropped in the last twenty minutes or so of the test to 164¡F and none of the other thermocouples got that hot. The temperature at the beginning of the test was 88¡F so this was a maximum temperature rise on the unheated side of the wall of 76¡ F.

I believe I saw that one point as high as 169 degrees - but that's a relatively insignificant difference (and the final report will likely include all the numbers as recorded by the instrumentation).

Again for context: The average temperature increase allowed in this test is 275 degrees F above the starting temp across all the 9 sensors, and 325 degrees F for any single sensor. This wall had a single point rise of just 76 or so degrees.

Significantly, when the test panel was pulled away from the furnace, the entire stucco skin on the heated side of the wall fell away. There was a flame-up that lasted less than a minute and went out on its own. So when the hose stream test began, it was blasting on unprotected bales! This is pretty close to the worst case scenario - bales on edge, with all the poly ties burned away, and no stucco to deflect the water stream. And it still passed.

Essentially the only things holding the bale remains in place was the bond to the stucco on the back wall, and the little bit of precompression we put on the wall (less than 3 1/2 inches on a 10ft high wall, as we precompressed by pounding in wedges of split 2x4 between the frame and a piece of ply at the top of the wall). But they were in there quite tight. I pulled some handfulls loose from a corner to see the extent of charring and they came out without too much force, but the rest of the wall is still intact. The hose portion of the test blew away most of the charred straw so that there was only 1/4 inch or so of charred straw before you get to basically undamaged straw.

 Warmest regards (and I do mean warmest - it must be over 100¡ outside now...)

Don't worry, the news report on my drive home predicted just 97 tomorrow. A Texas cold snap!

Bill Christensen
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