# An Investigation on the Synthesis of Alkali Activated Materials from Thermally Modified Clays
## 2 Experimental Conditions
### Characterization Methods  
The precursors' particle size distribution was determined by laser diffraction (Coulter LS230 analyzer) combining the laser diffraction technique and polarization intensity differential scattering (PIDS). The chemical composition of the precursors was obtained using X-ray fluorescence (Philips X'Pert PRO MPD spectrometer), with loss on ignition (LOI) at 1000 \({}^{\circ}\)C also determined. The crystallinity of the starting precursors and binders was  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline  & \multicolumn{4}{c}{**Mixture Proportion (wt.\%)**} & \multicolumn{1}{c}{**S/L ***} & \multicolumn{1}{c}{**C/S ***} & \multicolumn{1}{c}{**SH/SS ***} & \multicolumn{1}{c}{**NaOH**} & \multicolumn{1}{c}{**Curing**} & \multirow{2}{*}{**Factor**} \\ \cline{2-2} \cline{5-10}  & **MK** & **SF** & **CRC** & **NaOH** & **Na\({}_{2}\)SiO\({}_{3}\)** & **wt.\%** & **wt.\%** & **wt.\%** & **mol/dm3** & **Cond.** & \\ \hline SL0.90 & 37.8 & 9.5 & 0.0 & 31.7 & 21.1 & **0.9** & 4.0 & 1.50 & 10.0 & C1 & \\ SL1.00 & 40.0 & 10.0 & 0.0 & 30.0 & 20.0 & **1.0** & 4.0 & 1.50 & 10.0 & C1 & S/L ratio \\ SL1.10 & 42.0 & 10.5 & 0.0 & 28.5 & 19.0 & **1.1** & 4.0 & 1.50 & 10.0 & C1 & \\ \hline CS4.00 & 40.0 & 10.0 & 0.0 & 30.0 & 20.0 & 1.0 & **4.0** & 1.50 & 10.0 & C1 & \\ CS3.50 & 38.9 & 11.1 & 0.0 & 30.0 & 20.0 & 1.0 & **3.5** & 1.50 & 10.0 & C1 & C/S ratio \\ CS3.00 & 37.5 & 12.5 & 0.0 & 30.0 & 20.0 & 1.0 & **3.0** & 1.50 & 10.0 & C1 & \\ \hline HS1.50 & 40.0 & 10.0 & 0.0 & 30.0 & 20.0 & 1.0 & 4.0 & **1.50** & 10.0 & C1 & SH/SS \\ HS1.25 & 40.0 & 10.0 & 0.0 & 27.8 & 22.2 & 1.0 & 4.0 & **1.25** & 10.0 & C1 & ratio \\ HS1.00 & 40.0 & 10.0 & 0.0 & 25.0 & 25.0 & 1.0 & 4.0 & **1.00** & 10.0 & C1 & NaOH M \\ \hline M8 & 40.0 & 10.0 & 0.0 & 30.0 & 20.0 & 1.0 & 4.0 & 1.50 & **8.0** & C1 & \\ M10 & 40.0 & 10.0 & 0.0 & 30.0 & 20.0 & 1.0 & 4.0 & 1.50 & **10.0** & C1 & NaOH M \\ M12 & 40.0 & 10.0 & 0.0 & 30.0 & 20.0 & 1.0 & 4.0 & 1.50 & **12.0** & C1 & \\ \hline C1 & 40.0 & 10.0 & 0.0 & 30.  
assessed by X-ray diffraction (XRD). Experiments were carried out on a Bruker D8 Advance (Bruker AXS, Karlsruhe, Germany) (CuKa radiation, 5-70\({}^{\circ}\), 0.05\({}^{\circ}\) step, and 1 s/step, with the support of a position sensitive detector) and on a Rigaku Geigerflex D/max-Series instrument (Rgaku Corporation, Tokyo, Japan) (CuKa radiation, 10-80\({}^{\circ}\), 0.02\({}^{\circ}\) step and 10 s/step). The phase identification was performed by means of the Match! program package (Crystal Impact GbR, Bonn, Germany), supported by the database ICDD-PDF-2. Binder samples were collected from the mechanical tests after 28 day of curing, ground, sieved (\(\leq\)63 \(\upmu\)m), and kept sealed prior to testing. The bulk density of the binders and mortars was determined by the relation between the weight and volume of each sample. The weight (0.1 g accuracy) and dimensions (0.01 mm accuracy) of each individual specimen were measured after 7 and 28 days of curing. The Archimedes method (using water as the immersion fluid) was employed to evaluate the water absorption and open porosity after 28 days of curing. The compressive strength of the binders was determined using a Universal Testing Machine ([PERSON] model AG-25 TA) running at a displacement rate of 0.5 mm min\({}^{-1}\). A minimum of four cylindrical specimens were tested per formulation and curing age (7 and 28 days), and the average strength values are reported here after computing the correction factors for cylindrical specimens as prescribed by ASTM C42/C42M [50]. The compressive strength of the mortar specimens was determined as per EN 1015-11 [49]. To further complement the characterization of the CRC mortars, consistence (flow table test), fresh density, dynamic elasticity modulus, and capillary index were determined as per EN1015-3 [51], EN 1015-6 [52], EN 12504-4 [53], and EN 1015-18 [54], respectively.