According to Technology News 10/21/2009:
Researchers at the Missouri University of Science and Technology have received $567,000 to explore how carbon fibers could improve the blast and impact resistance of conventional reinforced concrete.
According to Dr. Jeffrey Volz, professor of civil and architectural engineering, “The fibers will absorb more energy as they pull out during the pressure wave or impact, cutting down on the potential for failure during an explosion or earthquake, The fibers will also significantly diminish secondary fragmentation, reducing one of the leading causes of damage to surrounding personnel and materials.”
Fiber in concrete has been used for a very long time, primarily as a substitution for welded wire mesh on SOG and occasionally in structural elements.
Let’s not forget that one of the most important functions of fiber is to eliminate cracks due to shrinkage as water evaporates, increasing the tensile strength of concrete.
The reason that the size of fiber used in concrete is extremely small -- half of one inch in length, at max -- is the fact that fiber has the tendency to stick together and “ball up” when concrete is being mixed.
Researchers are very much aware of this characteristic. They intend to use fibers as long as 6 inches, and to identify a technology that permits the coating of the fiber particle, thus reducing the effect of coagulation or “balling up”.
Upon consideration, a serious question arises:
Is this research contemplating a possible elimination of conventional reinforcing, or, does it see it as a supplement to the conventional reinforcing, and, before spending over half of a million dollars, wouldn’t a feasibility cost study regarding the cost of coating the carbon fiber make sense?