Abstract: Waste steel slag and tires are two major industrial solid wastes. Utilizing waste tire rubber particles as a lightweight material for the heavier steel slag, the rubber-steel slag mixed filler is used to replace the drying sand and gravel, which aligns well with the national policy of energy conservation and environmental protection. Because the physical and mechanical characteristics of steel slag have the characteristic of time, in order to study the dynamic characteristics of rubber-steel slag filler considering the time effect, the resonance column test is employed to investigate the influence of hydration period, rubber particle content and rubber particle size on the dynamic shear modulus, damping ratio, and other dynamic characteristics of the rubber-steel slag filler. Based on the Hardin-Drnevich hyperbolic model, a dynamic characteristic model of the rubber-steel slag filler after curing is established. The Botlzman function is used to describe the variation law of the maximum dynamic shear modulus and the reference range of the maximum damping ratio. It is concluded that the dynamic shear modulus of the rubber-steel slag filler with a rubber mixing ratio of 5% is the largest, and the density improvement is obvious. The mixing of rubber particles with a smaller size helps to improve the hydration potential, while the mixing of rubber particles with a larger size does not significantly improve the hydration potential. The optimal ratio of rubber-steel slag filler is 0−1 mm rubber particle size and 5% rubber particle content. Compared with the dynamic properties of traditional sand, it is concluded that the dynamic shear modulus of the rubber-steel slag filler before hydration is slightly higher than that of traditional fine sand. After 90 days of hydration, the dynamic shear modulus is close to the level of Harbin medium sand and slightly lower than Fujian standard sand. Under corresponding engineering conditions, the rubber-steel slag filler can be used as a substitute for sand. Through microscopic electron microscope testing of the rubber-steel slag filler particles, it is found that the hydration reaction of the rubber-steel slag filler can be divided into five stages: latent, induced, erosion, accelerated, and slowed down. The mixing of rubber particles makes the hydration reaction lag, and its medium-term structural form changes but does not affect the hydration product changes.

Key words: steel slag, rubber particles, dynamic shear modulus, damping ratio, hydration reaction, microstructure