These are cheap fiberglass, probably made in China, not only would they just collapse during a fire per the video of a test setup, but there is also the issue of aging and exposure to sun/UV causing the material to lose strength.
Since I am a traditional materials sculptor I am pretty familiar with fiberglass and various resins, I refuse to use them because I know they are just garbage and will deteriorate from sunlight, weather and age and become brittle, and start chalking. All of these plastics have a limited lifespan, sunlight is probably one of the biggest killers of the stuff next to age where the stuff starts to break down chemically from the inside out.
I have heard of some older (1950s) resin sculptures kept in a glass case in a museum because the stuff has the strength now of sugar cubes.
Any aging tests done on this material is being done in the field- live in real time, no one really knows what will happen to these plastics, resins and fiberglass in 20, 50, 75 or 100 years until it reaches those milestones.
I'm amazed these columns with no internal metal or wood support are even allowed to be installed supporting anything more than a little decorative garden gazebo or trellis!