Fracture Toughness of Fiber Reinforced Sulfur Concrete
J. L. K. Ho and R. T. Woodhams
Appears on pages(s):
compressive strength; concretes; cracking (fracturing); crack propagation;fiber reinforced concretes; flexural strength; glass fibers; hardness;polyethylene terephthalate; polypropylene fibers; sulfur; synthetic fibers.
The influence of chopped rovings on the fracture toughness, i.e., the flexural and compressive strength of sulfur concrete was evaluated by flexural and compression tests. Fracture energy was found to be sensitive to the length and concentration of the added rovings. Under optimum conditions the fracture toughness could be increased by more than a factor of 20 at fiber concentrations approaching 10 percent by weight of the sulfur content. For optimum performance the chopped rovings should be near their critical pullout length. The preferred length is between 4 and 5 cm for ease of mixing and dispersion. Two types of fibers are compared: a polyester type (polyethylene terephthalate) and a glass fiber type (alkali-resistant). The glass fibers increased maximum flexural load by a factor of 3.5 and the compressive strength by 50 percent whereas the polyester fibers increased maximum flexural load marginally by a factor of 1.3 and compressive strength by 33 percent at the op tim urn fiber length concentration. Incorporation of a minor quantity of these chopped fibers or rovings in to sulfur concrete offers a convenient and simple technique for improving the fracture toughness and ductility of this material.