Long-terms tests on circular plates were proposed by Bernard  with the aim of characterizing creep deformations in cracked conditions for fibre reinforced shot- crete elements. Recently long term tests on square panes have been proposed by Larive et al. . The interpretation of the results of these tests presents complications similar to those discussed in Sect. 4.2, which in this case are increased by the static redundancy of the specimens and by the presence of multiple cracks. Furthermore, more complex experimental setups are typically required. Alternative testing procedures proposed by Ciancio et al. are being investigated by the Authors to this aim [49, 50].
A significant deal of research has been focused, in recent years, on the characterization the long-term behaviour of FRC elements in cracked conditions. Even if different researchers are converging on similar testing protocols the following main conclusions can be drawn from the literature review presented by the present paper:
- - standard testing protocols, and relationship among main deformation parameters, need to be developed in order to allow and easier comparison of results and to facilitate discussion among researchers.
- - The extent to which parameters such as creep load ratio, crack opening at the beginning of the long-term test, temperature and relative humidity influence the behaviour of FRCs has not yet been fully defined.
- - Chemical, physical and mechanical phenomena governing creep of FRCs in cracked conditions have no yet been fully understood.
- - The conditions for the onset of tertiary creep have not been yet fully understood.
- - Inverse analysis procedures are most probably required for the interpretation of long-term bending tests.
- Prediction models for FRC creep in cracked conditions and in particular for tensile creep are not yet available but are needed if these phenomena are to be included in design.
Acknowledgments The Authors would like to acknowledge the contribution of all the members of the RILEM TC 261-CCF for their important contributions to the round table from which this paper was derived.