Dynamic Characteristics of Clay-Rubber Mixtures: Perspective on Small-Strain Dynamic Shear Modulus and Damping Ratio

Area of Science:

• Geotechnical Engineering
• Material Science

Background:

• Waste tire rubber-soil mixtures are utilized in geotechnical engineering for vibration attenuation due to their low density and high energy dissipation.
• Understanding the small-strain stiffness of clay-rubber mixtures (CRM) is crucial for their effective application.

Purpose of the Study:

• To investigate the evolution of small-strain stiffness characteristics of CRM.
• To analyze the influence of confining pressure (σ3), rubber particle content (Crubber), and rubber particle size (Drubber) on CRM stiffness and damping.

Main Methods:

• Resonance column tests were performed on CRM samples with varying σ3, Crubber, and Drubber.
• Small-strain stiffness characteristics, including dynamic shear modulus (G) and damping ratio (D), were determined.
• The Hardin-Drnevich equation was used to analyze G-γ curves and obtain the maximum dynamic shear modulus (Gmax).

Main Results:

• Confining pressure (σ3) increased G and decreased D.
• Increased rubber particle content (Crubber) significantly decreased G and increased D.
• Increased rubber particle size (Drubber) slightly increased G and increased D.
• An empirical equation for Gmax was proposed, considering σ3, Crubber, and Drubber.

Conclusions:

• Rubber particles generally inhibit the development of small-strain stiffness in CRM.
• The contact area between clay and rubber particles influences the mechanical behavior of CRM.
• The study provides a predictive model for Gmax and an empirical equation for D-γ curves in CRM.