The effect of different fiber combination on the thickness of V-shaped reinforced concrete folded plate elements produced with steel fiber reinforced SCC

Folded plates are widely used in some buildings (industrial buildings, hangars, warehouses, swimming pools, etc.) due to their natural rigidity and high load bearing capacity, as well as their economic advantages and aesthetic appearance. The use of such reinforced concrete (RC) load-bearing elements in the roof carrier system of long-span structures may provide a lighter and more economical. However, the thickness of RC folded plates is an important parameter for flexural performance. Although there is no experimental study in the literature on the effect of thickness on flexural performance, studies on its numerical solution are sufficient. In this study, the effect of fiber combination on the thickness of V-shaped RC folded plates produced from steel fiber reinforced self-compacting concrete (SFR-SCC) was investigated. For this purpose, control, single and hybrid steel fiber self-compacting concrete (SCC) mixtures were obtained by trial & error method and then, compressive, splitting and flexural tensile strength tests were performed on 3-, 28- and 90-day specimens. After that, a total of eighteen plain, single and hybrid steel fiber reinforced V-shaped RC folded plate samples having three different plate thicknesses (60, 70 and 80 mm) produced from SCC were prepared. 90-day V-shaped RC folded plates were subjected to four-point bending loading. Load bearing capacity, load-displacement behavior, toughness and ductility values as well as cracking patterns for all specimens were found. In conclusion, it has been determined that the use of SFR-SCC in the production of V-shaped RC folded plates provided significant advantages in terms of reducing the plate thickness. In particular, it has been observed that the thickness of V-shaped RC folded plates could be effectively reduced and the flexural performance could be improved by using hybrid steel fibers. In addition, an empirical formula obtained by regression analysis is proposed for the estimation of the thickness of V-shaped RC folded plates produced from SFR-SCC, and this formula has a high accuracy estimation with R2=0.97. In addition to all these, a design method is also proposed to estimate the nominal moment bearing capacity of V-shaped RC folded plates with some assumptions based on the ACI 544 regulation.