## 1 Introduction  
Earthquake engineering research has promoted the development of seismic control elements to mitigate the impact of earthquakes at various economic and social levels [1, 2, 3]. Among these, elastomeric isolators have demonstrated significant performance improvements. These devices decouple buildings from their foundations, reducing the vibrations transmitted from the ground to structural elements and consequently minimizing damage to the structure during an earthquake [1, 4, 5, 6, 7, 8, 9, 10, 11, 12]. Studies have analyzed the performance of low-cost unbonded fiber-reinforced elastomeric isolators (UFREIs) [13; 14], while [PERSON] [15] and [PERSON] [16] have investigated the development of these devices in Colombia. These isolators are made from natural rubber (UN-FREIs) and a rubber compound recycled from used vehicle tires (UR-FREIs). In general, the reduced cost of these isolators is attributed to the selection of materials that are readily available in the country, allowing for local fabrication and eliminating the need for imports [15]. Additionally, implementing these control elements in low-rise buildings could reduce repair costs and lost profits after a seismic event [15]. Full-scale experimental and numerical studies of fiber-reinforced elastomeric isolators (UFREIs) [17] provide valuable insights into their mechanical behavior under bidirectional excitation and the seismic response of a reinforced concrete building isolated with UFREIs. The physicochemical degradation of cementitious materials by agents such as carbon dioxide (CO\({}_{2}\)) in the atmosphere [18; 19], saltwater in coastal areas [20; 21; 22]; and relative humidity are examples of current exposure conditions that have not been studied in low-cost seismic isolators, despite their known impact on reducing the service life of conventional concrete structures [18; 19]. Since UN-FREIs and UR-FREIs remain installed in buildings for several years, it is necessary to determine whether the environmental conditions responsible for degradation in conventional structures could also affect the mechanical properties of these seismic control devices and compromise their structural function. Additionally, elastomers and polymers undergo photodegradation due to ultraviolet (UV) radiation from the sun [23; 24; 25]. However, studies on the influence of this factor have been largely limited to bridge rubber bearings [26; 27], without considering the potential exposure of UN-FREIs and UR-FREIs to UV rays during installation or storage. As a result, there is limited knowledge about the influence of these environmental conditions on the behavior of isolators throughout their service life and their implications for the response of an isolated building or bridges with deteriorated isolators [28]. The importance of elastomeric isolators in earthquake engineering has led researchers to focus on analyzing the degradation of rubber's mechanical properties under specific environmental conditions over time. For example, standardized tests such as ASTM D573-04 [29] establish a method for evaluating rubber deterioration when exposed to elevated temperatures in a hot air oven. The objective is to determine the effects of thermal aging on the physical and mechanical properties of rubber compounds. Some studies [26; 27] have developed tests to assess the degradation of natural rubber and high-cushion rubber caused by factors such as thermal oxidation, ultraviolet exposure, ozone, low-temperature ozone, saltwater, and acid rain. These studies concluded that thermal oxidation at 70 \({}^{\circ}\)C is the dominant aging process, affecting rubber performance and negatively influencing the seismic response of isolated bridges. Research on natural rubber has shown that thermal oxidation increases stiffness [30]. Conversely, exposure to low temperatures induces the crystallization of natural rubber, which can decrease the material's equivalent horizontal stiffness and damping over a prolonged period [31].