## 2 Materials and Methods
### Materials, Manufacturing, and Characterization Methodologies
#### 2.2.2 Manufacturing Process  
The laboratory-manufactured batches were processed using a vertical-axis planetary concrete mixer with a capacity of 100 liters, handling 63 liters per batch. The concrete mixing procedure involved sequential steps: initially, dry mixing of hydraulic lime and fine aggregate for one minute, subsequent addition of 90% water over one minute, followed by an additional minute of mortar phase mixing. The superplasticizer admixture and the remaining water were then introduced for one minute, with an additional minute of mortar mixing. Subsequently, the mixing operation was briefly halted to clear material adhering to the mixer's bottom and blades. Coarse aggregate inclusion followed, with an additional two minutes of concrete mixing. Finally, the introduction of PVA fibers (in concretes with fibers) took place over one minute. The entire mixing process continued for three more minutes, concluding with the fresh state characterization of the concrete. This mixing sequence adapts our established protocol for producing Portland cement concrete [27,29]. In particular, the mixing times established in each phase have been determined and optimized based on initial tests and studies conducted in our laboratory.  
Post-mixing, the concrete was poured into two types of steel molds: cylindrical specimens measuring 150 \(\times\) 300 mm\({}^{2}\) (diameter \(\times\) height) and prismatic specimens measuring 420 \(\times\) 100 \(\times\) 100 mm\({}^{3}\) (length \(\times\) width \(\times\) height). After casting, the specimens were stored in a room for 24 h. Subsequently, they were demolded and placed in a climatic chamber with constant temperature and humidity conditions (20 \(\lx@math@degree\)C \(\pm\) 0.5 \(\lx@math@degree\)C, and 98% \(\pm\) 0.5%, respectively) until the designated testing age. The testing age was 28 days for quasi-static characterization of compressive strength and elastic modulus, and 156 days for another  
\begin{table}
\begin{tabular}{c c c|c c c c c c} \hline \hline  & & & & \multicolumn{4}{c}{**Raw Materials [kg/m\({}^{3}\)]**} \\
**Name** & _w/l_\(\boldsymbol{\ell}\) & _SP/l_\(\boldsymbol{\ell}\) & \(w\) & _SP_ & _FA_ & _CA_ & \(f\) (\(\boldsymbol{\phi}_{f}\)) \\ \hline FFLC-0.0 & & 0 & & & 0 & & 0 (0\%) \\ FFLC-0.3 & & 0.0017 & & & 0.571 & & & 4.0 (0.3\%) \\ FFLC-0.6 & 0.8 & 0.0033 & 343.2 & 274.6 & 1.143 & 972.0 & 597.0 & 8.0 (0.6\%) \\ FFLC-0.9 & & 0.0033 & & & 1.143 & & & 12.0 (0.9\%) \\ FFLC-1.2 & & 0.0065 & & & 2.215 & & & 16.0 (1.2\%) \\ \hline \hline \end{tabular}
\end{table}
Table 1: Mix design composition of FFLC (kg of raw materials in a cubic meter of hydraulic- lime concrete).  
Figure 1: (**a**) Particle size distribution of aggregates; (**b**) polyvinyl alcohol fibers.  
quasi-static characterization of compressive strength concurrent with dynamic fracture tests. Please note that the improvement of mechanical properties over time in NHL 3.5 is slower than in higher classes. Therefore, we decided to conduct the tests at 156 days, approximately 5 months. This time frame represents a point at which the rate of strength development becomes significantly low [8]. One week before testing, a notch, reaching a depth of 1/6 the height of the specimen, was created at the center of prismatic specimens for hydraulic lime concrete both with and without fiber reinforcement.