Over recent decades, numerous strong earthquakes have caused widespread devastation, including citywide destruction, significant loss of life, and severe structural damage. Seismic base isolation is a well-established method for mitigating earthquake-induced risks in buildings; however, its high cost often limits its implementation in developing countries. Simultaneously, the global rise in vehicle numbers has led to the accumulation of discarded tires, intensifying environmental challenges. In response to these issues, this study investigates the development of a seismic isolator matrix using recycled rubber from vehicle tires, proposed as a sustainable and cost-effective alternative. Ten recycled rubber matrices were experimentally evaluated for their physical and mechanical properties. The matrix with optimal granulometry and binder content, demonstrating superior performance, was identified. This optimized matrix underwent further validation through compression and cyclic shear tests on reduced-scale prototypes of fiber-reinforced isolators, which included five prototype designs, two of which featured flexible reinforcement. The best-performing prototype comprised a recycled rubber matrix with 15% binder and glass fiber, exhibiting vertical stiffness and damping characteristics superior to those of natural rubber. Specifically, this prototype achieved a damping ratio of up to 22%, surpassing the 10% minimum required for seismic isolation, along with a vertical stiffness of 45 kN/mm, critical for withstanding the vertical loads transferred by buildings. These findings suggest that the recycled tire rubber matrix, when combined with glass fiber, is a viable material for the production of seismic isolators. This combination utilizes discarded materials, contributing to environmental sustainability.

Base isolators, traditionally made from natural rubber reinforced with steel sheets (SERIs), mitigate energy during seismic events, but their use in developing countries has been limited due to high cost and weight. To make them more accessible, lighter, cost-effective reinforcement fibers have been utilized. Additionally, the increasing use of natural rubber has caused waste storage and disposal issues, contributing to environmental pollution and disease spread. Exploring recycled rubber matrices as alternatives, this study improves seismic isolators’ mechanical properties through modified reinforcements and layer adhesion. Eight reinforcement materials and eight adhesives, which may be activated with or without heat application, are systematically evaluated. Employing the chosen reinforcements and adhesives, prototypes are tested mechanically to examine their vertical and horizontal performance through cyclic compression and cyclic shear testing. Two innovative devices using recycled rubber matrices were developed, one using a layering technique and another through a monolithic approach shaped with heat and pressure. Both integrate a fiberglass mesh reinforced with epoxy resin; one employs a heat-activated hybrid adhesive, while the other uses a cold bonding adhesive. These prototypes exhibit potential in advancing seismic isolation technology for low-rise buildings in developing countries, highlighting the viability of recycled materials in critical structural applications.

El aislamiento sísmico es una de las metodologías de diseño estructural para mitigar o reducir los daños ocasionados por el efecto telúrico, ya que, el uso de estos dispositivos ayuda a la disipación de energía causada por los terremotos. Dentro de estos, se encuentran los aisladores sísmicos de caucho natural, reforzado con materiales como acero (SREIs por sus siglas en inglés) o con fibras (FREIs por sus siglas en ingles). Los dispositivos reforzados con platinas de acero presentan gran peso, llegando hasta una tonelada o más, además, el costo es muy elevado por la labor de preparar las platinas de acero haciendo un proceso muy extenso de manufactura. Por otro lado, los aisladores que se han reforzado con fibra presentan mayor flexibilidad y su rigidez vertical aportada en el aislador es muy similar a la presentada en los SREIs, además, las fibras pueden ser orientadas en cualquier dirección, conduciendo a un mejor comportamiento vertical y reduciendo el abombamiento lateral del elastómero. Se tiene como objetivo caracterizar la fibra de refuerzo para un aislador sísmico de caucho reciclado, a través del ensayo mecánico de Tensión (ASTM C1557-20), donde se espera obtener el módulo de elasticidad para definir si la fibra a emplear podrá comportarse óptimamente en el aislador.