## 2 The Role of Cellulose Waste in Sustainable Construction
### Sustainable Concrete Alternatives
Additionally, cellulose-reinforced concrete often requires less energy to produce than traditional concrete, further contributing to its sustainability [14]. Nonetheless, the inclusion of organic components, such as waste paper, in concrete raises concerns regarding long-term durability, particularly in relation to water absorption and potential fiber degradation. Several studies have reported that prolonged exposure to moisture can weaken the fiber-matrix interface and reduce mechanical stability over time. Compared to other secondary resources, cellulose-based additions are particularly suited for enhancing tensile strength and reducing brittleness in cementitious materials, although their long-term performance is more sensitive to environmental exposure and fiber degradation. To mitigate these effects, strategies such as pre-treatment of paper fibers, incorporation of pozzolanic materials, or the use of hydrophobic admixtures are being explored to improve water resistance and prolong the service life of such concrete formulations. Over the past decade, there has been a focused effort to explore the incorporation of agricultural waste products as alternative aggregates in both traditional concrete and bio-aggregate concrete. A wide range of these materials, including hemp, coconut shells, oil palm shells, corncob, straw, bamboo, and cork, have been explored for this purpose [99]. [PERSON] et al. [100], analyzed the specific mechanical properties of concrete integrated with hemp fibers, noting improvements in tensile strength and reductions in density, which offered lightweight construction benefits. They found that adding 5% hemp fiber to the concrete mixture increased the tensile strength by 10% while reducing the overall weight of the concrete by 15%. Rice husks are another agricultural by-product being utilized in concrete. Each kilogram of milled white rice generates roughly 0.28 kg of rice husks, which are typically used in energy generation or composing. However, studies have shown that rice husks can be incorporated into concrete for their insulating properties. [PERSON] et al. [101] compared rice husk concrete with hemp concrete and found that, while rice husk concrete showed lower mechanical performance, it offered superior thermal insulation, with thermal conductivity values ranging between 0.10 and 0.14 W/mK, making it a viable eco-friendly material for filling walls. Additionally, [PERSON] et al. [102] also demonstrated the suitability of rice husk concrete for use in acoustic barriers and thermal insulation in multilayer systems, highlighting its versatility and environmental benefits. Hemp shiv, another agricultural by-product, is widely recognized for its ecological benefits in construction, especially in the form of hempcrete. Hemp shiv, the woody core of the hemp stalk, is mixed with a binder, such as lime, to form hempcrete, which is valued for its excellent insulation properties and carbon sequestration capabilities. Hempcrete has been used in both prefabricated masonry blocks and as an in situ cast material, offering advantages such as lower thermal conductivity and improved sustainability compared to traditional con crete. The use of lime-based binders further enhances hempcrete's environmental impact by reducing its carbon footprint [92]. Compared to mineral-based reinforcements, such as slags or tailings, cellulose fibers are particularly advantageous in enhancing tensile performance and reducing brittleness in lightweight applications, although their susceptibility to moisture-induced degradation remains a technical limitation.