Engineered Cement Uses Polymer Fibers

You might not think of cement as an engineering material because of its brittleness. But a new engineered cement composite developed at the University of Michigan may cause you to think again. Specially coated fibers replace stone aggregate and act as ligaments that tie the cement together under stress. Engineering Professor Victor Li comments: “How the fiber works inside the composite—especially when loading is excessive and the crack starts to break—needs to be just right. it means that fibers don’t come out too easily. Otherwise you don’t have a composite per se. On the other hand you don’t want them bonded too strong. If that was the case you wouldn’t allow the fiber to slide; you would break the fiber. In either case it would return to a brittle material as opposed to the ductile behavior we are looking for.“