Title: Steel Fiber Reinforced and Plain Concrete: Factors Influencing Flexural Strength Measurement

Author(s): Colin D. Johnston

Publication: Journal Proceedings

Volume: 79

Issue: 2

Appears on pages(s): 131-138

Keywords: fiber reinforced concretes; flexural strength; flexural tests; loads (forces); plain concrete; span-depth ratio; specimens; standards; statistical analysis; strength analysis; structural design.

DOI: 10.14359/10888

Date: 3/1/1982

Abstract:
The development of standards for testing fiber reinforced concrete is a current concren to many involved with the desing and use of the material. Because of its increased use in forms of construction where flexural performance is important, eg. pavement, a standard for flexural testing of fiber reinforced concrete is urgently needed. The major factors influencing flexural strength measurement are identified, i.e., specimen span, width, depth, and ode of loading. It is hown how these factors can be accounted for by a single parameter that represents the volume of material in a definable zone of probable material failure. Analysis of the author's expeimental data and comparable data from other sources shows the variation of flexural strength with this volume parameter to be similar for both fiber reinforced and plain concretes. A relationshp is developed which permits the flexural strength in any testing relationship to be predicted from the value obtained in any other arangement. The strength of a 18 x 6 x 6 in. (450 x 150 x 10 mm) specimen tested under third-point loading is used as a reference.