The term "glass-fiber reinforced" always seems to refer to the use of synthetic resins. Couldn't glass fibers also be included in a cement mortar and at considerably less cost?
The possibilities for using glass as both reinforcement and prestressing tendons in concrete have been recognized for quite some time and have been the subject of considerable research. Theoretically the advantages should be great, but there are various problems and at the moment costs are substantially higher with no great practical advantage. The Russians are reported to have used glass-fiber mats in the same way as with resin fabrication. Strength, using an alumino-cement, is then claimed to be 6 to 7 times greater than that of reinforced concrete and twice that or ordinary mild steel. Weight is 4 to 8 times less than steel, and 3 times that of reinforced concrete, but the report says that for many applications the higher strength and low weight can offset this. Ordinary portland cement cannot be used unless the glass fibers are specially treated with a caustic-resistant medium to avoid attack by the calcium hydrate present. In the Russian studies, the glass fibers are laid over a mortar layer as random-dispersed mats, about 1 mm thick. A troweled-on layer of mortar follows, and the building-up then continues until a desired thickness has been reached. No vibration or compression is necessary.