## 5 Conclusions  
In this paper, a new composite floor system using cold-formed thin-walled C steelchannels embedment and foam concrete slab is developed. This new type of floor system features lightweight, high fire-resistant, and high anti-corrosion features, and can be used for multi-story buildings, providing a promising new alternative floor system for the construction market.  
The full-scale tests as well as FE modelling were performed to study the flexural capacity and failure mechanism of composite foam concrete slabs using cold-formed thin-walled C steel channels.  
Using the FE model, main factors, such as the density of the foam concrete, the strength of the steel, and the spacing of the cold-formed thin-walled C steel channels are studied. The below findings are made:  
1. The test shows that the composite floor formed by foamed concrete and cold-formed thin-walled C steel channels shows good bearing capacity and deformation capacity, but the stiffness of the composite floor is relatively small. When reaching the limit state, the upper and lower flanges and part of the webs of the cold-formed thin-walled C steel channels have reached the yield strength, and the plastic deformation of the composite floor has been fully developed.
2. The comparison of the load-deflection curve and load-strain curve shows that the simulation results are in good agreement with the test results.
3. The smaller the spacing of cold-formed thin-walled C steel channels, that is, the greater the steel content, the higher the load-bearing capacity of the composite floor.
4. The higher the compressive strength of the foamed concrete, the higher the bearing capacity of the composite floor slab, while the stiffness increases.
5. The increase of the steel strength of the cold-formed thin-walled C steel channels can increase the bearing capacity of the composite floor, but it has almost no effect on the stiffness of the composite floor.  
Figure 21: Load displacement curves of different grades of foam concrete.  
The limitation of the project research is that, as a new material, high-density foam concrete is used. The rigidity of this new composite floor slab is relatively small, and cracks often appear prematurely. Researches on mechanical properties of this type of floor is still little and not mature enough, and the modelling analysis in this article does not consider the bond slip between the cold-formed thin-walled C steel channels and foam concrete. In future studies, in-depth and detailed research will be carried out in response to the limitations of this research. In the meantime, research on two-way composite slabs and composite shear walls and the connection between the slabs and walls will also be conducted.  
Original draft preparation: D.L. and F.F.; conception: D.L. and F.F.; test and data processing: W.L.; writing--review and editing: F.F.; project administration: D.L. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Natural Science Foundation of China, grant number 51378238.  
Not applicable.  
The data used to support the findings of this study are available from the authors upon request.  
The authors declare no conflict of interest.