PSI - Issue 78

Emanuele Brunesi et al. / Procedia Structural Integrity 78 (2026) 161–168

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floor stability wall underneath them was removed and replaced by a mortar joint in such a way that continuity between the wall and slab precast elements could be ensured/restored. This, in turn, shows how high the effects can be of such a common operation in terms of resistance, which in turn reaffirms how much of a weakness – such – connections can be for such a precast technology/construction system. If Figure 6 and Figure 7 collect notable outcomes for the precast wall-slab-wall structure case, as a result of shake table testing and pseudo-static cyclic testing, respectively, Figure 8 closes this Section presenting key hysteretic data obtained for the third full-scale building mock-up, namely the single-storey two-bay cast-in-place lightly reinforced concrete specimen described in Brunesi et al. (2018b) and shown in Figure 4. More specifically, Figure 8 shows force displacement response curves in longitudinal and transverse directions of the tested building specimen, rendering clear that structural response was driven by issues of rocking in both – weak and strong – directions.

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Force - Displacement cycles

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Fig. 8. Hysteretic response curves of the pseudo-statically tested cast-in-place specimen – longitudinal and transverse directions.

Rocking was definitely the dominating response mechanism observed for both building directions, with only very limited sliding being recorded, given that the cohesion between the base of the walls and the top surface of the concrete foundations was high enough to prevent the latter mechanism from occurring. In the longitudinal direction, the mock up building was pushed to levels of drift more than six times larger than the one that had produced the first signs of damage to the structure, with some relatively modest post-peak softening being obtained because of the equally modest rocking-induced concrete crushing at the base of the walls. In the transverse direction, drifts of about 0.6% were high enough to mobilise a clear in-plane rocking mechanism of the three walls, which activated simultaneously. A decision not to go beyond that level of displacement/drift was thus made, mainly because there was little additional information that could be gained with the undertaking of further pure rocking response cycles. Additional cyclic inelastic testing in longitudinal direction was instead undertaken, up to a drift of 3.0%, to demonstrate that the relatively modest post peak softening was almost completely insensitive to previously accumulated damage in the other building direction. Another noteworthy aspect related to the weak building direction is that the behaviour of the building is not symmetric in the pulling and pushing directions, which can be ascribed to the arrangement of starter rebars and, more in general, to the construction process of this typology of cast-in-place houses. 4. Auxiliary testing Auxiliary testing efforts were undertaken for material characterisation purposes and for the purposes of behavioural characterisation of structural components and items. In addition to standard compressive tests on concrete cubes and cylinders, as well as tensile tests of steel rebars, four-point bending tests were carried out on wall and slab strips that feature the same type of plain steel bars and reinforcement arrangement as the walls and slabs of the cast-in-place test specimen, which permitted the calibration of numerical models to reproduce the full-scale building test (Brunesi et al. 2018b). Such testing efforts are anyway not reported here, due to page limits, and the same applies to a variety of tests related to the precast building specimens (e.g. tensile tests of steel connectors for wall-to-wall connection, compression tests of concrete cubes, compression and three-point flexural tests on high- and low-strength mortar for connectors as well as mortar joints under precast wall panels and wall-slab gap-filling mortar joints, triplet and bond wrench tests to