## 2 Materials and Methods
### Cement Mortars  
The following materials were used to generate the different cement mortars mixtures:  
* _White Cement_. White cement with limestone, called BLII/A-L 42.5 R, was used. Its compressive strength at 28 days is greater than 42.5 MPa and it presents a high initial resistance, according to Spanish Cement Instruction standard [31]. Its chemical composition is detailed below (Table 4);
* _Sand_. The aggregate used for the mixture's preparation was natural and had a maximum size (MAS) of 4 mm (Figure 2). This parameter was determined according to the UNE-EN 933:1 standard [32]. The bulk density and the porosity presented values of 1600 kg/m\({}^{3}\) and 37.8%, respectively. Finally, the apparent particle density and water absorption presented values of 2600 kg/m\({}^{3}\) and 0.47%, respectively. All these magnitudes were determined according to the UNE-EN 1097:6 standard [33];
* _Water_. In order to obtain an appropriate workability for the mortars, and to favor the comparison of results, the quantity of water used was the same for all the mixtures. Four different mortars were produced at different biocercamics content ratios, 0.1, 0.25 and 0.4% (CBC-0.1, CBC-0.25 and CBC-0.4). The quantity of biocercamics added was measured by the weight of the aggregate. A reference mortar made with no biocercamics addition was also manufactured. For each mixture, 12 pr  
Figure 2: Sand grading curve with a maximum aggregate size (MAS) of 4 mm. 160 \(\times\) 40 \(\times\) 40 mm\({}^{3}\) were manufactured and tested. The cement/aggregate ratio of 0.3 was kept constant in all mixtures to identify the influence of bioceramics in mortar mixtures. Table 5 shows the composition of the specimens. In this study, the water/cement ratio of 0.6 was kept constant to identify the influence of bioceramics in mortar mixtures (Table 5). Therefore, in the same way as it occurred in gypsum samples, it was found that as the amount of bioceramics added increased, the mortars set quicker and the workability of the samples was reduced. After the specimens were produced, they underwent a curing process at 20 \(\pm\) 2 \({}^{\circ}\)C for 28 days. During this period, relative humidity was maintained constant at 95 \(\pm\) 5% for the first 7 days and at 65 \(\pm\) 5% for the remaining 21 days, according to the UNE-EN 1015-11 standard [34]. After curing, the pieces were tested, as established in the experimental plan. Thus, the following fresh and hardened properties of the mortars were tested:  
* _Fresh State Bulk Density:_ It was determined by dividing its mass by the volume it occupies when it is introduced into a measuring vessel with a known capacity, following the specifications detailed in the UNE-EN 1015-6 standard [35];
* _Dry State Density:_ Once the mortar hardened, the values of the dry state density were estimated. It was calculated after the curing process described above for 28 days and determined by obtaining the mass in the dry state of a specimen and dividing it by its volume when it is immersed in water in a saturated state, as is specified in the European Standard UNE-EN 1015-10 [36];
* _Water Absorption by Capillarity:_ It was determined using three specimens. They were dried until they reached their constant mass. They were then split and the coefficient of water absorption was determined by measuring the increase in mass after immersing the fractured surface of the dried specimen in 5-10 mm of water for a period of time, following the experimental procedure described in UNE-EN 1015-18 [37];
* _Mechanical Properties:_ All samples were characterized by flexural and compressive strength tests after 28 days, according to the European Standard UNE-EN 1015-11 [34]. Flexural strength was determined using the prismatic samples of 160 \(\times\) 40 \(\times\) 40 mm\({}^{3}\) and applying a load until failure. After the bending test, the two resulting pieces were tested to compressive strength.