Glass Fiber Reinforced Concrete – How over designed is GFRC made with Trinic’s GFRC Admix? Sometimes we get a clue when a piece is made wrong and needs to be scrapped. We don’t recommend using less fiber in all of your pieces but you can use less fiber in pieces that will not see as much strain such as tiles. All powder GFRC Admixtures: http://www.trinic.us/Trinic-Admixtures_c22.htm | Trinic LLC.