Sustainable Approach of Using Arundo donax Leaves Reinforced Cement Mortar/Fly Bottom Ash Composites

Earlier research suggested using ash to substitute cement, whereas other studies looked at the possibility of using plant-derived agricultural wastes as fiber reinforcement in cement applications. This study offered an environmentally friendly option to change traditional mortars by replacing cement with fly bottom ash (FBA) waste at 10, 20, 30, and 40 wt %. Likewise, Arundo donax leaves (ADL) were employed to reinforce the modified cement mortars at 0.4, 2, 5, and 7 wt %. X-ray diffraction analysis of used materials was performed. The morphology of composites made with FBA and ADL was investigated using scanning electron microscopy. Moreover, the density, water uptake, thermal conductivity, energy gain, and carbon dioxide (CO₂) emissions of the prepared composites were discussed. Their flexural strength, compressive strength, and displacement were also compared. Results revealed that the addition of FBA in the mortar matrix has a positive effect on decreasing the thermal conductivity and lightness of the mortar. In addition, 20 wt % of cement replacement by FBA guarantees simultaneously moderate mechanical properties, nearly 51% of energy gain, and 20% of total CO₂ emission reduction. In the same, adding ADL to the 20wt %FBA mortar reduced the thermal conductivity and the lightness of the mortar. The 0.4 wt % ADL reinforcement ensured 59% energy gain and 6% of total CO₂ emission reduction. A major amelioration was observed in the compressive strength (an increase of 14%) and in the plasticity (an increase of 27%) of the considered composite materials. In conclusion, using FBA as a cement replacement with low ADL content inclusion results in a thermal-resistant composite with reasonable durability and strength.