The footing is cast first and the wallis cast only after hardening of the footing. This corresponds to theusual construction schedule for a wall on a construction site. (4)The “HFC wall, with joint, 500 mm sleeves” is a HFC wall similarto wall no. (3). However, 500 mm long plastic pipes (sleeves) areslid onto each reinforcing bar to prevent the bond between thereinforcing bars and the HFC. Further details on these simulationscan be found in [4].The pushover curves of the four walls are displayed in Fig. 2and the following remarks can be made: (1) The “RC wall” reacheda displacement of 56 mm (2.2% drift) before the outer reinforcingbars reached their ultimate strain, assumed to be 0.07, and failedin tension. The displacement ductility at that point was about 8which is a rather high yet still reasonable value. (2) The elasticstiffness and the strength of the “HFC wall with no joint and nosleeves” were significantly higher compared to those of the “RCFig. 2. Monotonic pushover curves of different RC and HFC structural walls.wall”. This implies a significant contribution of HFC to the strengthand stiffness of the wall which is reasonable considering that theassumed equivalent tensile strength of HFC was 12 MPa at a strainof 0.01 [4]. When the principal tensile strain of HFC reached 0.01,thematerial started softening and the load-carrying capacity of thewall dropped. The softening of HFC occurred at one single locationleading to strain concentrations. All the following deformations ofthe wall basically occurred in one single horizontal cross-sectionleading to high local strains in the longitudinal reinforcement. Dueto this strain concentration the ultimate strain of the longitudinalreinforcing bars was reached when the top displacement wasjust 28 mm (1.1% drift), implying that the displacement capacityof such a HFC wall would be much lower than that of thepreviously discussed “RC wall”. At that point of the simulation theresistance of the wall did not drop sharply because the fractureof the reinforcing bars was not modelled. Within the scope ofthis problem no such structural wall with no joint and no sleeveswas tested because the predicted global softening and the reducedplastic deformation capacity were deemed to be unacceptablefor seismic application purposes. For this reason there is noexperimental evidence for the softening behaviour of HFC wallswith no joint and no sleeves. However, a similar phenomenon, i.e. a noticeable initial contribution of the fibre concrete to thestrength of the structural element followed by a global softeningbehaviour, is reported by [7] where the axial deformation capacityof large-scale prismatic barsmade of conventional fibre-reinforcedconcrete and featuring amild steel longitudinal reinforcementwasinvestigated. (3) In the “HFC wall with joint but no sleeves” astrain concentration took place already from the beginning of theloading phase. No fibres bridged the construction joint betweenthe footing and the wall, making it significantly weaker than theadjacent sections. All plastic deformations occurred at the jointand, as in the case of jacketed sections [2], the length of the plastichinge can be assumed to correspond to twice the strain penetrationlength. Due to the high tensile capacity of HFC it is believed thatstrain penetration is reduced compared to conventional reinforcedconcrete. This lead to significant strain concentrations and theultimate strain of the longitudinal reinforcing bars was reachedwhen the computed top displacementwas only 14mm(0.6% drift),which resulted in a deformation capacity that is a lot lower thanthat of the “RC wall”. Again, at that point of the simulation theresistance of the wall did not drop sharply because the fractureof the bars was not modelled. For seismic applications this wall isalso unsuitable. (4) To overcome the problem of excessive strainlocalization, 500 mm long sleeves were slid onto the longitudinalreinforcement in order to prevent its bond with the adjacent HFC
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