## 1 Introduction
Additionally, in fiber-reinforced mixes, the interfacial transit zones between the fibers and cement paste were found to contribute to the elevated permeability and carbonation rate. [PERSON] et al. [12] presented a review article to summarize strategies of utilizing rice straw in fiber or ash form to manufacture construction materials. The components manufactured from rice straw or rice straw ash can be used for facades, envelopes, composite bricks, backfills, mortar, rigid pavements, and hard wood composites. Paddy straw fibers, a locally available agricultural waste material, pose significant environmental hazards due to disposal issues and pollution caused by burning. This study focused on exploring the potential of using paddy straw fibers as a partial replacement for fine aggregates in concrete. Various mixes with different aspect ratios and replacement rates of paddy straw fibers were experimentally investigated by [PERSON] and [PERSON] [13]. The mechanical properties, including compressive strength and split tensile strength, were analyzed for the different concrete mixes. The results indicated that the concrete achieved its highest compressive and split tensile strengths when 1% paddy straw fiber replacement was used, and these strengths decreased with a higher fiber content. In summary, these studies suggest the potential for using organic material in concrete mixes to improve its mechanical properties under specific conditions or its physical and thermal characteristics. Chemical analysis, scanning electron microscopy, organic matter content determination, and pozzolanic analysis are crucial for characterizing a material, determining if it reacts chemically with calcium hydroxide to produce cementitious compounds, and revealing how this process takes place during hydration. Such studies can effectively provide relevant information regarding components, and they are widely used when the cementitious material is replaced by an alternative solution [14; 15; 16]. For instance, [PERSON] et al. [17] provided a comprehensive review of the application of sugar cane bagasse ash as a construction material. This material has pozzolanic characteristics, which can enhance both fresh and hardened concrete properties. Important factors affecting pozzolanic activity, such as the calcination and recalcination temperature and duration, fineness, loss on ignition (LOI), and crystal silicon dioxide, were discussed in detail. The paper concluded by recommending further research to optimize and broaden the utilization of sugar cane bagasse in construction materials. Organic material burned until ash is obtained has also been used as a partial replacement for cement due to the pozzolanic characteristics of the ash powder. For instance, the effect of maize cob ash as a supplementary cementitious material on the mechanical properties of concrete was studied in [18; 19]. Generally, it can be concluded that maize cob ash can be used as a partial replacement for cement in concrete. Sugarcane bagasse ash has been studied as a replacement for sand content, producing mortars with better mechanical results than the reference samples [20; 21; 22]. Hazelnut shell ash was studied in [23; 24] to quantify the pozzolanic reaction when cement was replaced. The assessment of incorporating hazelnut shell in the manufacturing processes of cement and concrete holds potential for advancing the sustainability objectives of the cement industry while concurrently addressing the issue of waste accumulation from the hazelnut processing sector. In order to find alternative materials that could partially replace fine aggregates without significantly compromising the properties of concrete, great efforts have been put into the study and characterization of waste organic materials. One such material is crushed hazelnut shell (herein referred as HS), an agricultural waste that is generated in large quantities. In Chile, it is estimated that by the year 2030 there will be 60,000 ha planted, with a production scale in the order of 88,000 tons.