Improved 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. The debate on how it is measured, interpreted and used is still inconclusive. The objectives of the research program are hence to (a) investigate the influence of specimen size, loading configuration, and loading rate on the load-deformation characteristics of FRC (energy absorption, flexural strength, first-crack strength and elastic modulus), (b) evaluate the effectiveness of the currently used toughness indices and associated specifications, (c) provide an analytical basis for the interpretation and use of the strength and toughness data, and (d) recommend guidelines for the use of flexural strength and toughness data in specification, design and performance evaluation. The investigation comprises experimental and analytical components. Since the scope of the problem is extensive and since statistically significant toughness data needs to be generated, an inter-university testing program involving six universities is included. As an outcome of the study, specific recommendations will be made on the use of the toughness data in specification, design and performance evaluation of fiber cement composites.
