## 1 Introduction  
There is a growing inclination towards promoting contemporary sustainable construction. Research explores materials like earth-based concrete [1; 2], hemp concrete [3], etc., particularly suited for applications where high mechanical strength is not essential. For instance, hemp concrete demonstrates strengths ranging from 0.1 to 1.6 MPa after 28 days. Notably, a material gaining special relevance in this context is natural hydraulic lime, despite having mechanical properties below those of Portland cement. It offers distinct advantages, primarily cost-effectiveness and reduced environmental impact, as supported by recent studies [4]. This trend extends to hydraulic lime concrete for similar reasons. Furthermore, lime-based materials are especially suitable for the restoration of masonry buildings. In this sense, these mortars must fulfill compatibility and serviceability criteria, thus the importance of their detailed characterization [5]. With this respect, several papers focus on searching for compatible mortars to restore various structures, such as the case of the work by [PERSON] et al. [5] centered on the earthquake protection of the Kaisarini Monastery in Greece; or the work by [PERSON] et al. [6] focused on the characterization of original mortars from a Venetian Villa in Chania, Crete; or the case of [PERSON] et al. [7], who deal with the characterization of the crushed brick/lime mortars of [PERSON]'s Hagia Sophia to resist earthquake stresses. Recently, in 2022, [PERSON] et al. [8] wrote the RILEM TC 277-LHS report on lime-based mortars for restoration, where they define the theoretical background and experimental developments plus positive and negative practical experiences in lime-based binders and mortars. These lime mortars, as also happens with lime concretes, present an inherent fragility common to most cementitious materials. To counterbalance this drawback, incorporating fibers becomes crucial to enhance energy absorption capacity and ductility under various quasi-static and dynamic solicitations. This requirement has generated considerable interest in research [9]. While there is abundant scientific literature addressing the influence of different fiber types on the mechanical behavior of Portland cement concrete, the same cannot be said for natural hydraulic lime concretes. Existing studies are exclusively focused on lime mortars. Let us delve into some of the most noteworthy studies. [PERSON] et al. [10] conducted a study on hydraulic lime mortars reinforced with varying amounts and lengths of fiberglass. They observed a significant increase in the mechanical properties of the composite in quasi-static conditions, proportional to the fiber content. Notably, there was a substantial increase in fracture energy, followed by flexural strength, tensile strength, and compressive strength, in that order. This study suggests that fiberglass-reinforced lime mortar could be a viable alternative for the restoration and strengthening of historical structures [10]. [PERSON] et al. [4] investigated hydraulic lime mortars reinforced with basalt fibers in both quasi-static and dynamic regimes. The inclusion of fibers led to an increase in porosity, resulting in lower quasi-static compressive and flexural strengths as the fiber content increased. However, the reinforced mortars exhibited a more ductile and tough behavior. In the dynamic regime, direct tensile strength increased, showing high sensitivity to deformation velocity. Fracture energy also increased with the loading rate [4]. They concluded that basalt fiber-reinforced natural hydraulic lime mortars present good dynamic mechanical properties and may be a viable binder material for the recovery of cultural heritage. [PERSON] et al. [11] studied hydraulic lime mortars reinforced with basalt fibers and different types of aggregates, showing improvements in post-cracking behavior and compressive strength, largely dependent on the matrix and basalt fiber type.