Comparison of shrinkage cracking performance of different types of fibers and wiremesh

Concrete structures shrink when they are subjected to a drying environment. If this shrinkage is restrained, then tensile stresses develop and concrete may crack. One of the methods to reduce the adverse effects of shrinkage cracking is to reinforce concrete with short randomly distributed fibers. Another possibility is the use of wiremesh. The efficiencies of fibers and wiremesh to arrest cracks in cementitious composites were studied. Different types of fiber (steel, polypropylene, and cellulose) with fiber content of 0.25% and 0.5% by volume of concrete were examined. Ring-type specimens were used for restrained shrinkage cracking test. These fibers and wiremesh show significant reduction in crack width. Steel fiber reinforced concrete (0.5% addition) showed 80% reduction in maximum crack width and up to 90% reduction in average crack width. Concrete reinforced with 0.5% polypropylene or cellulose fibers was as effective as 0.25% steel fibers or wiremesh reinforced concrete (about 70% reduction in maximum and average crack width). Other properties such as free (unrestrained) shrinkage and compressive strength were also investigated.