## 3 The Use of Agro-Wastes in Concrete Production
### Other Agro-Wastes and Lightweight Concrete Applications  
AWs like sugarcane, pineapple waste, and walnut shells can also enhance concrete's strength and compressive strength [2]. Studies have shown that such wastes benefit concrete strength, compressive strength, thermal insulation, and sound insulation in non-load-bearing structures. For example, sugarcane bagasse Ash has been reported to enhance thermal insulation properties [66], while walnut shells contribute to reducing sound transmission in lightweight concrete applications [67]. Pineapple fiber-based composites have also demonstrated improvements in both compressive strength and insulation capabilities [68].  
Overall, research shows that using AWs as alternative materials in concrete production provides environmental sustainability and economic benefits. In lightweight concrete applications developed for non-load-bearing structural elements, wastes like CS [40; 43], PO Ash [44; 45], RHA [46; 47], and WS [21; 65] offer positive contributions to properties such as strength, thermal insulation, and sound insulation. Using these wastes in conjunction with other cementitious materials increases concrete's compliance with standards, expanding its potential applications (Table 3). Future studies should further investigate these materials' long-term durability, thermal performance, water absorption behavior, and mechanical strength properties under various loading conditions.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Agro-Waste** & **Concrete** & & & **Environmental** & & \\
**Type** & **Additive** & **Impact Fields** & **Features** & **Sustainability** & **Economic Benefits** & **Related** \\  & **Purpose** & & & & **Contribution** & & \\ \hline \multirow{3}{*}{Coconut Shell} & Partial & Compressive strength, & Lightweight & Reduction of & Low-cost & \\  & replacement of & lightness, water & concrete & natural resource & alternative for & \\  & coarse aggregate & absorption resistance & production, low & use, waste & lightweight & \\  & & & specific gravity & management & concrete production & \\ \hline \multirow{3}{*}{Coconut Fiber} & Reinforcement & Mechanical strength, & Increase in tensile & & Recycling of & Production of \\  & in cement & thermal conductivity & strength, increase & fibers and waste & low-density & [26; 30; 35; 36] \\  & & & in ductility & & & building materials \\ \hline \multirow{3}{*}{Palm Oil Fuel Ash} & Partial & Compressive strength, & Strength increases & & & \\  & replacement & lightness, & with heat & & & \\  & of cement & environmental & treatment, low & & & \\  & & contribution & density & & & \\ \hline \multirow{3}{*}{Rice Husk Ash} & Partial & Compressive strength, & Increased & Reduction of & & \\  & replacement & durability & strength with & industrial waste, & & \\  & of cement & durability & optimal 20\% & lower carbon & material & \\  & & replacement & footprint & & & \\ \hline \multirow{3}{*}{Wheat Straw and Ash} & Insulation & Thermal insulation, & Energy saving, & Natural & Reduction in energy & \\  & material, cement & compressive strength, & cost reduction & alternative and & & \\ \cline{1-1}  & replacement & mechanical strength & energy saving & & & \\ \hline \hline \end{tabular}
\end{table}
Table 3: Technical, environmental, and economic contributions of agro-wastes to concrete (own research).