Influence of fiber reinforcement on strength and toughness of all-lightweight concrete

• Steel, vinylon and polyethylene fibers were applied to an all-lightweight concrete.
• All the fibers are very effective to increase the flexural strength.
• The fracture toughness of the concrete was improved significantly with steel fibers.

The effect of fiber reinforcement on all-lightweight concrete in which both fine and coarse aggregates are artificially lightweight was investigated experimentally. Three different fibers (i.e., steel, vinylon and polyethylene) were compared for their effects on the compressive strength, splitting tensile strength, flexural strength, shear strength, and toughness. Normal concrete with the same compressive strength as the all-lightweight concrete was prepared as a reference. Using 1.5% vinylon fibers significantly improved the flexural strength of the all-lightweight concrete 234% higher than that of normal concrete. Using 1.2% steel fiber increased the fracture toughness of the all-lightweight concrete more than twelve times.