# The Behaviour of Half-Slabs and Hollow-Core Slab in Four-Edge Supported Conditions
## 3 Results
### Effect of Short-Term Loading  
At each sequence of short-term loading, the LGF model exhibited significantly greater displacements than the LGR model. The recorded final deflection at the midspan (panel no. 6) of the LGF model was 1.93 mm, and the deflection of the LGR model was greater by 38% and equal to 2.67 mm. The deflection of 3.90 mm was observed for the RP model under the maximum loading at panel no. 7 (aligned values on a length of 1.2 m from the centre of the slab). No decrease in displacement was observed for the first two models when half the loading was relocated (the loading sequence was changed from J-10 to L-12). The displacement of the RP model was slightly reduced near the support (panels no. 2-3) by 0.14 mm. The maximum displacement of the LGF, LGR and RP models was found at a distance of 0.60-1.2 m from the slab centre. The fourth model made of HC slabs had a different behaviour. The load relocation reduced the displacements in one half of the model (panels no. 2-5), and their maximum value reached 0.44 mm. As opposed to the RP model, the greatest rotation was observed not close to the support but at a distance of 1.2 m from the centre of the slab. Unlike in other models, no significant drop in deflection at panel no. 8 was observed for the HC slab under the loading sequences J-10 and L-12. For the LGR, LGF, and RP models, the difference between the readings at the edge of panel no. 8 was 30% of the maximum displacement. For the same panel of the HC model, the difference in the reading was 10%. No longitudinal cracks were found in the RP and HC models. The RP model was characterised by greater stiffness related to the slab thickness; however, the observed deflections were greater by 9% than the HC model under the loading sequence L-12. Even more significant discrepancies were shown for the sequence E-5, for which the difference amounted to 50%. A similar situation was found for the LGF and LGR models, where a difference in the sequence E-5 was equal to 84%. Notably, the step-by-step verification of the bottom surface did not reveal any new cracks. They were observed only during the loading sequence J-10. Results from the short-term tests performed on individual models at the selected loading sequences are shown in Figure 15.  
Graphs in Figure 16a,b show the comparison of displacements of the measured points on X- and Y-axes (longitudinal and lateral directions) for the sequence J-10. The displacements in the LGF model were 39% greater than those in the LGR model and 26% greater in the RP model compared to the HC model. The displacements in the LGR and LGF models demonstrated high similarity along the two axes. Similar behaviour was observed for the RP model. However, a different flatter displacement curve was observed for the HC model. The observed deflections near the supports were relatively higher than in the case of the other three models. Moreover, only the HC model did not have the maximum deflection at the midspan but at a distance of 0.625 m from the midpoint. The HC model, the only one made without concrete topping, showed behaviour closer to the model of the hinge joint between panels, consistent with that presented in Figure 1 and adopted in the standard [52]. Such a model justifies greater displacement closer to the support, resulting  
Figure 14: Cracks on the LGR model exposed to long-term loading: (**a**) in the interface between the bond beam and the masonry unit (corner B) and (**b**) between the lintel and the masonry unit. from greater rotations in the shear keys between the panels closer to the support. The maximum displacements of individual models are compared in Table 4.