## 2 Definition, Classification, and Potential Applications of Agro-Wastes  
AWs consist of plant- and animal-derived materials generated from agricultural and livestock activities. These wastes can generally be categorized into three main types: plant-based wastes, animal-based wastes, and food processing wastes. \begin{table}
\begin{tabular}{c c c c c} \hline
**Agro-Wastes** & **Potential Advantages** & **Challenges** & **Sample Applications** \\ \hline \multirow{4}{*}{Rice Husk Ash} & - & Can be used as a cement substitute in concrete production & - & Not yet widely available in terms of cost-effectiveness & - High strength concrete structures \\  & - & Increases durability & - & Homogeneity and purity of waste can affect & - Flooring materials \\  & - & Supports & production processes & & \\  & environmental sustainability & & & & \\ \hline \multirow{4}{*}{Coconut Shell} & - & Increases strength of concrete & - & Mechanical performance is & \\  & - & Advantages in earthquake & & not as stable as some & \\  & - &  Advantages in earthquake & & traditional materials & - Reinforced concrete beams \\  & & situations due to its flexibility & - & Procurement and processing & - Lightweight \\  & & and lightness & & of waste can create & \\  & & logistics costs & & \\ \hline \multirow{4}{*}{Palm Oil Ash} & - & Sustainable additive in concrete production & - & Waste cleaning and processing can be costly & - Partial structural improvements in concrete beams \\  & - & Reduces carbon footprint & - & Limited regional access limits & - Bas \\  & - & & widespread use & - & Insulation materials \\ \hline \multirow{4}{*}{Wheat Straw Ash} & - & Can increase strength in production of geo-polymer beams & - & Geo-polymer technology is & \\  & & production of geo-polymer beams & - & & \\  & - & Provides lower carbon & & wheat straw can be & \\  & & emissions in concrete mixes & & logistically challenging & \\ \hline \multirow{4}{*}{Hazelnut shells} & - & Increases the flexural strength of concrete & - & Local production and & \\  & - & Provides a potential & & collection processes can & - Lightweight \\  & - & Provides a potential & & be costly & \\  & - & alternative to & - & Homogeneity and quality & - \\  & & lightweight aggregates & & control can be difficult & \\ \hline \end{tabular}
\end{table} 
Table 1: Agro-waste types and their usage fields in the construction sector (own research; detailed references are discussed in Sections 3 and 4). Plant-based wastes are derived from plant production and processing activities. For example, residues such as straw, leaves, husks, and fruit pits result from agricultural activities. Materials like rice husk, wheat straw, and coconut shell fall under this category of AWs. Given their positive effects on concrete properties, such as strength and permeability, or their ability to enhance mechanical properties, reduce plastic cracking, and improve impact resistance, these wastes hold potential for use in concrete production in the construction industry. They are generally low-density and organic in nature, making them particularly appealing for lightweight concrete production [29; 30]. Animal-based wastes from livestock activities include materials such as manure, hair, hooves, hides, bones, and blood. These wastes can be used as organic fertilizers and evaluated as biomass for energy production. Processing animal wastes for organic fertilizer production or converting them into biomass for energy generation is an important step for environmental sustainability [31]. Food processing wastes arise from processing activities in the agriculture and food industries. Examples include pulp generated during juice production or husks and seeds released during oil processing. These wastes can be utilized as fertilizer or energy sources through composting or pyrolysis processes. Some of these wastes also have potential applications in the construction sector [32].