Deflection measurements and toughness evaluations for FRC

✍ Scribed by Zeyad M. El-Shakra; Vellore S. Gopalaratnam

• Book ID: 103002222
• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 725 KB
• Volume: 23
• Category: Article
• ISSN: 0008-8846
• DOI: 10.1016/0008-8846(93)90082-k

✦ Synopsis

The article discusses issues related to the accuracy of deflection measurement in the flexural testing of fiber reinforced concrete. It is observed that the ASTM and the old ACI toughness indices which are based on measuring deflection at first cracking are influenced significantly by errors in the deflection measurement. This is primarily because up to first-crack, these errors often overshadow true first-crack deflections. Errors in deflection measurement result in negligible errors in toughness computations using either the JCI definition of flexural toughness or the new ACI definition of toughness index. Elastic punching deformation at the specimen support has been identified as a major source of the extraneous deformation. Approximate equations to predict this deformation have been presented. The elasticity-based equations are more realistically sensitive to specimen size and material properties than similar equations obtained using plasticity concepts.