Title: Comparative Toughness Testing of Fiber Reinforced Concrete

Author(s): L. Chen

Publication: Symposium Paper

Volume: 155

Issue:

Appears on pages(s): 41-76

Keywords: fiber reinforced concretes; fibers; flexural strength; polypropylene fibers; steels; strength; tests; toughness; Materials Research

DOI: 10.14359/928

Date: 8/1/1995

Abstract:
Round-robin tests of the flexural toughness of fiber reinforced concrete were carried out using six different testing machines in five different laboratories. Six groups of beams, including a plain concrete control, two different volumes of polypropylene fibers, and three different volumes of steel fibers were tested in accordance with ASTM C 1018, with special care taken to exclude the "extraneous" deflections due to deformations at the specimen supports. The results from each laboratory were used to compute the ASTM C 1018 toughness indices I 5, I 10, I 20, I 30, and I 50 and the corresponding residual strength factors R 5,10, R 10,20, R 20,30, and R 30,50. In addition, the JSCE Toughness and Toughness Factor were also computed. It was found that, although the load vs. deflection curves were inherently quite variable, in most cases there was no significant difference among the participating laboratories, except for those mixes with a very low toughness. It was also found that the ASTM C 1018 toughness indices, particularly I 5 and I 10, did not discriminate very well between the different fiber contents or different fiber types; the JSCE parameters were rather more successful in this regard.