# Real Cyclic Load-Bearing Test of a Ceramic-Reinforced Slab
## 6 Conclusions  
Derived from the analysis and the real loading test in particular, the results show that the typical ceramic-reinforced slabs that were built during the 1960s and 1970s in Spain are rigid solutions with very high load-bearing capacities. The results from the test allow us to conclude that the analyzed slab, 230 mm thick and only 2.2 kN/m\({}^{2}\) in weight, resists up to 7.5 kN/m\({}^{2}\) extra live load.  
Besides this, the structural response of the slab is mostly elastic up to advanced steps of loading, with all the advantages that this behavior implies. However, a slight plastic response was detected beyond approximately 5 kN/m\({}^{2}\), as this load level had never been reached before; the fact of going beyond the current load states implies a redistribution of the reinforcements within the section that results in plastic remaining strains (see the diagrams in Section 4). This effect is even enhanced when the load is cyclically repeated, although an evident hardening effect was also observed in the first early stages of loading. The hardening effect is directly derived from the relocation of re-bars, which takes place the first time and hardens during the following cycles.  
The results from the loading test show that deflections on the analyzed slab were very low compared with those on other slab types. The maximum mid-span deflection of the analyzed slab was 7 mm under 7.50 kN/m\({}^{2}\), which corresponds to L/685. This is mainly due to the structural response of the solution, which is mainly based on shear behavior and steel reinforcements. Deflections of the slab are mostly those derived from steel re-bars, with little interference by concrete and its typical creep.  
The slab response under vibration was better as the live load was increased. As a low self-weight solution with enhanced load-bearing capacity, problems derive more from serviceability than from ultimate strengths. This means that the analyzed slab, as a typical example of the ceramic-reinforced slabs which were used throughout Spain, works better when loaded in terms of dynamic response. When not loaded, the slab is uncomfortable for users due to the low fundamental frequency, which coincides with the vibration generated by humans walking. However, in the case of heavy machines with high frequencies, this is an ideal solution.  
For all these reasons, the typical ceramic-reinforced slabs which were used during the 1960s, 1970s, and even later in Spain, especially for industrial buildings, are very powerful slab solutions from all points of view. It is curious to see how a specific solution for slabs which is currently outside of the Standards is so efficient from several points of view. Obviously, always limiting spans under 5.00 m, as in the analyzed case, means it works basically under shear. This study on ceramic-reinforced slabs verifies that these specific solutions with almost no concrete work efficiently for some specific cases, which is opposite to the current Standard's postulates.  
The four authors were involved in the conceptualization, methodology, formal analysis, investigation, and data curation of this study. Writing--original draft: [PERSON]-[PERSON]; [PERSON]-[PERSON] and [PERSON]; Writing--review and editing: [PERSON]-V.; [PERSON]-[PERSON] and [PERSON]-C. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
We acknowledge the Serra Hunter Program for providing funds to carry out this research. [PERSON] acknowledges the financial support received from the \"Secretaria de Educacion Superior, Ciencia, Tecnologia e Innovacion\" (SENESCYT) for her doctoral studies at Polytechnic University of Catalonia (UPC).  
The authors declare no conflict of interest.