Two fire tests of 8-in, hollow-core specimens 40x48 in. in plan were carried
out. These tests were conducted to
evaluate the effects of roofing insulation on the temperature of the prestressing strand.
In one test, 23/4 in. of roof insulation
was placed on the side of the specimen
away from the fire. In the other test,
no insulation was used.
A comparison of the data obtained
shows that use of the roof insulation did
not result in higher strand temperatures. In fact, measurements show that
at durations of 1 hr and greater, average strand temperatures were consistently a few degrees less in the insulated
specimen.