Title: Fracture Toughness of Fiber Reinforced Concrete

Author(s): V. S. Gopalaratnam, S. P. Shah, Gordon Batson, Marvin Criswell, V. Ramakishnan and Methi Wecharatana

Publication: Materials Journal

Volume: 88

Issue: 4

Appears on pages(s): 339-353

Keywords: fiber reinforced concrete; flexural tests; fracture properties; impact strength; measurement; modulus of elasticity; strength method; stress analysis; Materials Research

DOI: 10.14359/1840

Date: 7/1/1991

Abstract:
Fracture and impact resistance are among the improved attributes of fiber reinforced concrete (FRC). Toughness, which is a measure of the energy-absorption capacity, is used to characterize FRC's ability to resist fracture when subjected to static, dynamic, and impact loads. There is still debate on how toughness should be measured, interpreted, and used. Results from the first phase of a six-university study funded by the Concrete Materials Research Council-American Concrete Institute and the National Science Foundation are presented in this article. The first phase includes specimen size, fiber volume content, fiber type, and the effect of a notch as the primary parameters of investigation. Results from the tests including toughness and other important properties such as stress at first crack, ultimate strength, and the elastic modulus as influenced by the preceding parameters are presented and discussed. The importance of making accurate deflection measurements and the influence of these measurements on the toughness and other flexural characteristics are discussed. Conclusions are made with regard to lessons learned from the inter-university testing program, drawbacks of some currently used measures of toughness, observed material property trends, and a possible alternate measure of toughness.