Hybrid fiber reinforcement and crack formation in cementitious composite materials

摘要

The use of different types of fibers simultaneously for reinforcing cementitiousmatrices is motivated by the concept of a multi-scale nature of thecrack propagation process. Fibers with different geometrical and mechanical propertiesare used to bridge cracks of different sizes from the micro- to the macroscale.In this study, the performance of different fiber reinforced cementitiouscomposites is assessed in terms of their tensile stress-crack opening behavior. Theresults obtained from this investigation allow a direct quantitative comparison ofthe behavior obtained from the different fiber reinforcement systems. The researchdescribed in this paper shows that the multi-scale conception of cracking and theuse of hybrid fiber reinforcements do not necessarily result in an improved tensilebehavior of the composite. Particular material design requirements may neverthelessjustify the use of hybrid fiber reinforcements.