## 2 Materials and Methods
### Experimental Tests in the Fresh State  
Fresh tests were performed to evaluate the flowability and passing ability of SCC. Slump-flow, 3-bar L-box, and 16-bar J-ring tests were conducted according to EN 12350-8 [58], EN 12350-10 [59], and EN 12350-12 [60], respectively. Three determinations were performed for each test in each SCC mix.  
* The slump-flow test (Figure 6a) consisted of allowing the free flow of SCC after putting it into the Abrams cone and carefully lifting it in a vertical direction. The maximum spreading diameter in two perpendicular directions was measured, whose average value is named SCC slump flow. The time that SCC took to reach a slump flow of 500 mm was also recorded (\(t_{500}\) time) [22].
* The 3-bar L-box test (Figure 6b) involved placing SCC in the vertical part of a 90-degree box. After that, a door located at the bottom of the vertical zone was opened, which allowed the concrete to flow through three bars simulating concrete reinforcement. The SCC flowed along the horizontal zone, with the SCC height being measured both  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Component**} & \multicolumn{3}{c}{**Comparative Composition**} & \multicolumn{3}{c}{**kg/m\({}^{3}\) Composition**} \\ \cline{2-7}  & **RW** & **W1.5** & **W3.0** & **RW** & **W1.5** & **W3.0** \\ \hline Cement & 320 & 320 & 320 & 318.8 & 305.1 & 293.9 \\ Water & 155 & 185 & 210 & 154.4 & 176.4 & 192.9 \\ Limestone sand 0/2 mm & 680 & 680 & 380 & 677.4 & 648.3 & 624.5 \\ Siliceous sand 0/4 mm & 660 & 660 & 660 & 657.5 & 629.3 & 606.1 \\ Siliceous gravel 4/12 mm & 600 & 600 & 600 & 597.7 & 572.1 & 551.0 \\ Superplasticizers & 6.7 & 6.7 & 6.7 & 6.7 & 6.4 & 6.1 \\ RCWTB & 0.0 & 24.5 & 49.0 & 0.0 & 23.4 & 45.0 \\ Volume (liters) & 1004 & 1049 & 1089 & 1000 & 1000 & 1000 \\ \hline \hline \end{tabular}
\end{table}
Table 2: SCC composition.  
Figure 6: Fresh tests in SCC: (**a**) slump-flow test; (**b**) 3-bar L-box test (“1” is the gate; dimensions in mm) according to EN 12350-10 [59]; (**c**) 16-bar J-ring test.  
at the end of the horizontal zone and before the gate when the SCC flow ended. The quotient between these two heights is named blocking ratio, which is the result of this test [28].
* Finally, the 16-bar J-ring test (Figure 6c) was performed identically to the slump-flow test, but placing a ring in the center of the concrete flow zone whose bars simulated concrete reinforcement. The same values as in the slump-flow test were measured, along with the difference in the height of SCC between the ring's center and immediately after the bars to evaluate the passing capacity of SCC. This value is referred to as the J-ring blocking ratio.  
Depending on the values obtained in each fresh-behavior test, SCC is assigned different classifications according to the indications of the European Federation of National Associations Representing for Concrete (EFNARC) [61], also detailed in the EN 206 standard [57]. These classifications provide a clear and quick approach to the fresh performance of SCC based on an experimental assessment. The classifications for the slump-flow, 3-bar L-box, and 16-bar J-ring tests are detailed in Table 3.