# Flexural Strength of Composite Deck Slab with Macro Synthetic Fiber Reinforced Concrete
## 6 Conclusions  
The aim of this study was to evaluate the flexural strength of a steel deck plate system reinforced with MFRC. To accomplish this, we conducted a four-point loading test for the positive moment and a three-point loading test for the negative moment. In the positive moment test, macro synthetic fiber dosage and existence of studs were the main variables. Macro synthetic fiber dosage and reinforcement ratio were the main variables in the negative moment test. From these experiments under limited conditions, the following conclusions were obtained. 1. In the uniaxial compressive strength test of concrete reinforced with macro-synthetic fiber, compressive strength and modulus of elasticity increased. Furthermore, the strength decreased more gradually after achieving the maximum compressive strength of the MFRC. In the flexural and splitting tensile strength tests, unlike other research results [6; 7] in which the tensile strength increased, there was little change in both parameters. It is judged that when the macro-synthetic fiber dosage is 2.4 kg/m\({}^{3}\), the fiber dosage is small; thus, the maximum tensile strength cannot be increased. However, after achieving the maximum strength, the specimens had sufficient residual strength until fracture. 2. The flexural strength and cracking load of all specimens increased according to macro synthetic fiber dosage. The increase in flexural strength was more pronounced in the negative moment region than in the positive moment region. In addition, since it was confirmed that the MFRC steel deck had greater flexural stiffness until yielding, it will be necessary to quantitatively evaluate the effect of MFRC on the effective flexural stiffness of steel docking in future studies. 3. According to the experimental results, we proposed a flexural strength model of a steel deck plate containing macro synthetic fiber. This model showed greater accuracy than the current standard when comparing the experimental results. However, due to the simple design process described here, the equation proposed does not consider the compressive force contributed by the steel deck. If the compressive force of the steel deck was considered in the precise analysis, it would be possible to predict flexural strength more accurately. 4. In future studies, the effect of macro-synthetic fiber on flexural strength could be predicted more accurately by performing flexural strength evaluation using various macro-synthetic fibers. Furthermore, when fiber-reinforced concrete is applied to a new slab system, the contribution of the fiber to the flexural strength could be examined. Original draft preparation and editing, D.-H.S. ; performing tests and investigations, D.-H.S., M.-S.L. ([PERSON]); analyzing the results and reviewing the article; B.-I.B., M.-S.L. ([PERSON]); supervision and review writing, C.-S.C. All authors have read and agreed to the published version of the manuscript. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \(M_{n,mrfrc}\) & \(P_{n,mrfrc}\) & \(P_{max,sw}\) & \(P_{max,sw}\) & \(P_{n}\) & \(P_{max,sw}\)/\(P_{n,mrfrc}\) \\  & **(kN-m)** & **(kN)** & **(kN)** & & \\ \hline P-Deck-F2.4S & 47.43 & 70.26 & 78.99 & 1.18 & 1.12 \\ N-Deck-F2.4-R0.91 & 46.03 & 46.03 & 53.40 & 1.37 & 1.16 \\ N-Deck-F2.4-R0.65 & 34.04 & 34.04 & 42.97 & 1.51 & 1.26 \\ N-Deck-F2.4-R0.39 & 21.55 & 21.55 & 28.26 & 1.62 & 1.31 \\ \hline \hline \end{tabular} \(M_{n,m/rfrc}\): flexural strength calculated by the proposed model, \(P_{n,m/rfrc}\): load of converting flexural strength with concentrated load \((2M_{n,mrfrc}/a)\), \(a\): distance between support and loading point, \(P_{n}\): nominal flexural load, \(P_{n,sw}\): modified maximum load considering weight of the specimen.  
\end{table} 
Table 9: Comparison of ultimate flexural strength between the standard [20; 29] and the model proposed here.