## 2 Materials and Methods
### Characterization of FM Adnixtured Mortars
#### 2.4.3 Hydration Degree  
When the major cement compounds, i.e., tricalcium silicates (C\({}_{3}\)S Equation (1)) and dicalcium silicates (C\({}_{2}\)S Equation (2)), are in contact with water, there is formation in the first few hours of calcium silicate hydrate (also called C-S-H), ettringite, and Portlandite (Ca(OH)\({}_{2}\)). Over time, it is possible to form calcium carbonate (CaCO\({}_{3}\) Equation (3)) in various forms--calcite, vaterite, and aragonite. These different compounds are dependent on the hydration of the cement grains. To quantify good cement hydration, [PERSON] developed a method based on thermogravimetric analysis [19]. The thermogravimetry allows the degradation of the hydration products by dissociation reactions--dehydration for C-S-H (Equation (4)), dehydroxylation for Portlandite (Equation (5)), and finally, decarbonation for calcium carbonates (Equation (6)). The hydration reaction of tricalcium silicates and dicalcium silicates is as follows:  
\[\text{Ca}_{3}\text{SiO}_{5}+6\text{H}_{2}\text{O}\rightarrow\text{CSH}+3\text{ Ca(OH)}_{2} \tag{1}\]  
\[\text{Ca}_{2}\text{SiO}_{4}+4\text{H}_{2}\text{O}\rightarrow\text{CSH}+\text{ Ca(OH)}_{2} \tag{2}\]  
That for Portlandite carbonation with ambient carbon dioxide is as follows:  
\[\text{Ca(OH)}_{2}+\text{CO}_{2}\rightarrow\text{CaCO}_{3}+\text{H}_{2}\text{O} \tag{3}\]  
The first reaction of CSH dehydration is given below [20]:  
\[\left(\text{CaO}\right)_{\text{a}}\text{-SiO}_{2}\text{-}\left(\text{H}_{2} \text{O}\right)_{\text{b}}\text{ }\text{ }\text{ }  
2.4.4. Mechanical Characterization of Mortars  
The strengths of the mortars were determined in compression at different curing times (28, 60, and 90 days) on a machine from Proviteto, France, with a load cell threshold of 100 kN. The strengths were obtained at a load rate of 2400 N\(\cdot\)s\({}^{-1}\) on twelve replicates according to the EN 196-1 standard. 2.4.5. Microstructure Visualization  
The morphology of the samples was studied using scanning electron microscopy (namely SEM). This analysis allowed visualizing the macro and microporosities of the different mortars. The micrographs were obtained using a PHILIPS FEG XL 30 microscope. To facilitate observation, the samples were first dried and then coated with a thin layer of spray-on gold to enhance their electric conductivities. SEM observations were coupled with an energy dispersive X-ray spectroscopy (EDS) analysis allowing the surface samples' elements identification. 2.4.6. Thermal Conductivities Determination of Mortars  
The samples (10 \(\times\) 10 \(\times\) 2 cm\({}^{3}\)) were cured for 28 days and then analyzed by transient plane source (TPS) 2500, HotDisk, to determine their thermal conductivities. Before measurements, the samples were dried in an oven at 50 \({}^{\circ}\)C for at least a week until a constant mass was obtained. Measurements were repeated three times. 3. Results and Discussion  
3.1. FM Characterization  
3.1.1. Proximate Composition of FMs  
The proportion of protein is 10.3%, and the quantity of carbohydrates is 45.1% mass of mucilage. The extracted product is relatively clean since the ash content (3.8%) is relatively low compared with values found in the literature [3; 4; 16; 22; 23]. All these values are highly affected by the process parameters [4; 24] and the flaxseed cultivar [3]. The polysaccharide composition is categorized into two distinct fractions. The neutral fraction consists of xylose and arabinose, forming arabinoxylans (AX). This fraction accounts for 72% of the total polysaccharides. The second fraction, constituting 28% of the polysaccharide content, is an acidic fraction primarily composed of rhamnose and galacturonic acid, resulting in type I rhamnosturonans (RG-I). [PERSON] [25] initially elucidated this mucilage separation into these two fractions. He noted that the neutral and acidic fractions make up approximately 75 and 25% of the polysaccharide content in mucilage, respectively.