## 2 The Role of Cellulose Waste in Sustainable Construction
### Cellulose-Based Composites and Bio-Based Materials  
Cellulose waste serves as a fundamental building block in the development of advanced composites and bio-based materials that are gaining traction in the construction industry. These materials leverage the natural properties of cellulose, such as its high tensile strength, biodegradability, and renewability, to create alternatives to conventional, often synthetic, building materials. Agricultural residue, such as straw and hemp, are particularly valuable in this context. Straw-based panels, for example, offer a sustainable alternative to traditional wood products. These panels are lightweight, durable, and can be produced with minimal energy input, significantly reducing the environmental impact associated with conventional wood processing. Furthermore, these insulating panels exhibit a high specific heat capacity of over 1600 J/(kg\(\cdot\)K), leading to a volumetric specific heat capacity of approximately 0.35 MJ/(m\({}^{3}\cdot\)K), despite their low density of around 210 kg/m\({}^{3}\), enhancing their thermal performance and making them highly efficient for energy conservation in buildings [76]. Hemp fibers, combined with lime, are used to create hempcrete, a biocompatible that is highly valued for its excellent thermal insulation, moisture regulation, and carbon-sequestrian capabilities. Hempcrete not only serves as a sustainable alternative to conventional construction materials but contributes to reducing the carbon footprint of buildings, as the hemp plant absorbs significant amounts of CO\({}_{2}\) during its growth, effectively capturing carbon that remains stored in the building material [77]. Furthermore, hempcrete is a carbon-negative material itself; for example, 1 m\({}^{2}\) of a hemp-lime wall (260 mm thick) requires 370-394 MJ of energy for production and sequesters 14-35 kg of CO\({}_{2}\) over its 100-year lifespan, compared to an equivalent Portland cement concrete wall that requires 560 MJ of energy and releases 52.3 kg of CO\({}_{2}\)[78]. Additionally, hemp-silica panels have demonstrated a thermal conductivity of 0.101 W/mK and an excellent moisture buffering value of 3.49, further enhancing their suitability for energy-efficient and moisture-regulating construction applications [79]. Cellulose from textile waste, particularly recycled cotton and linen, is being repurposed into fibers that enhance the mechanical properties of construction materials [80]. These fibers are used in concrete and other composites to improve tensile strength and durability, offering a sustainable solution for managing textile waste while contributing to the development of more resilient and long-lasting building \begin{table}
\begin{tabular}{c c c c} \hline
**SRM** & **Application** & **Dosage** & **Reference** \\ \hline HF & Reinforced foam concretes & 0.75–1.5–3\% by weight of cement & [65] \\ \hline HF & Mortars & 0.5 vol–1.0 vol\% & [66] \\ \hline BF/HF & Reinforced cement mortars & 0.34–0.5–0.68–1 vol\% & [67] \\ \hline HF & Mortars & 1 vol\% & [68] \\ \hline FF & Concrete & 0.3–0.6\% mass percentages & [69] \\ \hline FF & High-performance concrete & 0.15–0.30–0.50\% & [70] \\ \hline FF & Reinforced cementitious & 1.0 vol\% relative to the total batch volume & [71] \\ \hline FF & Cement-based composites & 0.3–0.6–0.9–1.2–1.5–1.8 by weight of cement & [72] \\ \hline FF & Ultra high-performance & 2–4–6 (kg/m\({}^{3}\)) & [73] \\ \hline FF & Concrete & 0.3–0.6\% (5.7–11.4 kg/m\({}^{3}\)) & [74] \\ \hline FF & Cementitious composite & 1.0–2.0–3.0\% vol & [75] \\ \hline \end{tabular}
\begin{tabular}{c c c} \hline BF: broom fibers; CF: cellulose fibers; CNC: cellulose nanocrystal; CNF: cellulose nanofibrils; FF: flax fiber; HF: hemp fiber; ZF: kepnief fibers; MCC: microcrystalline cellulose; MFC: microfibrillated cellulose; NFC: nanofibrilated cellulose; RCF: recycled cellulose fiber; SRM: secondary raw material; wt\%: weight percent. \\ \end{tabular}
\end{table} 
Table 1: _Cont._products.