Effect of Rubber Granulate Content on the Compressive Strength of Concrete for Industrial Vibration-Isolating Floors

Ensuring vibration and impact isolation is crucial in industrial flooring design, especially where vibroacoustic comfort is a priority. Excessive vibrations can negatively affect sensitive equipment, structural durability, and personnel comfort. With the rise of automation and high-precision processes, effective vibration control in floor systems is increasingly important. Traditional solutions like elastomer pads, rubber mats, or floating floors often have high installation costs, complex construction, and long-term degradation. Therefore, there is growing interest in integrated, durable alternatives that can be incorporated directly into concrete structures. One such approach uses rubber granulates from recycled tires as a modifying additive in cementitious composites. This can improve damping, enhance impact energy absorption, and reduce the need for external insulating layers. However, adding rubber particles to concrete may affect its compressive strength, a key design parameter. This article presents experimental research on concrete and mortar mixtures modified with rubber granulates for vibration-isolating industrial floor systems. The proposed solution combines a conventional concrete subbase with a rubber-enhanced mortar layer, forming a composite system to mitigate vibration transmission. Laboratory tests and real-scale verification under industrial conditions showed that the slab with hybrid EPDM/SBR rubber granulate mortar achieved the highest vibration-damping efficiency, reducing vertical acceleration by 58.6% compared to the reference slab. The EPDM-only mortar also showed a significant reduction of 45.5%.