Experimental Programme
The experimental campaign organised by Asquapro had two main aims: (1) To study the contribution of different fibres to the behaviour of sprayed concrete subjected to punching/bending stresses; (2) To develop a “standardisable” test for studying the creep behaviour of FRSC under a constant load.
Testing Programme
The programme consisted in characterising the fresh concrete properties and measuring the compressive strength, the energy absorption capacity and the creep deformation. More than 100 specimens were necessary to carry out the programme.
Concrete Mix Design
To ensure good comparability, the same concrete matrix was used for all types of concrete: reinforced or plain. A typical mix design used in France for sprayed concrete for underground support was chosen (see Table 1). Only the dosage of
Table 1 Concrete mix design
Component |
Designation |
Dosage (kg/m3) |
Sand |
0-4 mm |
1.041 |
Gravel |
4-11.2 mm |
729 |
Cement |
CEM I 52.5N SR3 CE PM-CP2 NF |
400 |
Admixture |
Tempo 11 (0.2-0.4 %) |
0.8-1.6 |
Water |
W/C = 0.475 |
190 |
superplasticiser was slightly modified from one type of concrete to another according to the different fibres. The grading envelope is consistent with the Asquapro recommendation and the NF 95102 French standard.