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In this article, steel slag was added into the marine silt to improve its dynamic properties. The characteristics of marine silt that can be studied by XRD, BET surface area, SEM, and FTIR were first described. Then, the influence of the sample density, water content, waste steel slag content, and the confining pressure on the dynamic shear modulus G and damping ratio λ was discussed by conducting resonant column tests. The results illustrated that the dynamic characteristics of the marine silt-steel slag admixtures were considerably improved. Additionally, G increased with the increasing steel slag content and λ increased with the decreasing steel slag content. Moreover, a dynamic model of the admixtures was developed based on the Hardin–Drnevich model. Furthermore, by comparing the dynamic characteristics of the admixtures with Nanjing sand, Fujian sand, Kiyohoro silty clay, and Wenzhou marine clay, it was found that the improved admixtures may be a more suitable geofiller in geotechnical engineering. [ABSTRACT FROM AUTHOR]

Due to the continuous scarcity of sand and gravel under environmental protection policies, a new geo-backfill material with the good liquefaction resistance is urgently needed. Steel slag is a kind of industrial solid waste. The aged eight-month steel slag usually could be used as backfill material. It is important to investigate the liquefaction resistance behaviours of steel slag. According to the soil classification method, the waste steel slag is also divided into gravel steel slag, coarse steel slag and fine steel slag. Dynamic triaxial tests were carried out to investigate the liquefaction resistance of gravel steel slag in the paper by considering the effects of consolidation stress ratio, loading frequency, confining pressure and gravel-size particle contents. The variations of pore water pressure and cyclic shear resistance were analysed. The calculation model of pore water pressure of saturated sand proposed by Seed and Finn could be applied to analyse the dynamic pore water pressure development of gravel steel slag. Compared with conventional soils, the cyclic liquefaction resistance of gravel steel slag is better than that of fine sand, gravel soil, sand-gravel soils and sand pebbles. Gravel steel slag can be used to replace some conventional cohesionless soils as a geo-backfill material. [ABSTRACT FROM AUTHOR]

To achieve recycled use of waste steel slag and waste tyres, it was proposed to incorporate waste tyre particles into waste steel slag and mix with sand to form a new geomaterial. Considering the effects of confining pressure, incorporation ratios of tyre particles and in corporation ratios of sand, the dynamic shear modulus and damping ratio of the new geomaterial were studied by a torsional shear vibration method based on resonance column tests. The specific control density of steel slag combined with different mixing ratios of tyre particles and sand were determined according to the relative density. The relationship between the dynamic shear modulus and the shear strain of the new geomaterial suited the hyperbolic model of Davidenkov. The maximum dynamic shear moduli of the new geomaterial with the tyre particle mixing ratio of 5% reached 166 MPa at the confining pressure of 200 kPa and were close to those of Fujian standard sand. The maximum dynamic shear modulus of the new geomaterial with the tyre particle mixing ratio of 15% was 103 MPa at the confining pressure of 200 kPa and was larger than those of Nanjing fine sand. The minimum damping ratio of the new geomaterial was in the range of 0·21–1·95% at the confining pressure of 200 kPa and was larger than that of the pure steel slag with 0·15–1·2%. These findings showed that the new geomaterial could be applied instead of sand. [ABSTRACT FROM AUTHOR]

Waste steel slag is a recycled industrial solid waste and is sometimes used as backfills, but the dynamic shear properties of waste steel slag have not been researched at present. To understand the dynamic shear properties of waste steel slag, the resonance column tests were carried out to investigate the dynamic shear modulus and damping ratio of the steel slag considering the effect of the relative density of steel slag and confining pressure. The maximum dynamic shear modulus was discussed, and the dynamic model of the steel slag was constructed by the Hardin–Drnevich model. The regression analysis of the normalized dynamic shear modulus ratio and damping ratio of the steel slag showed that the dynamic model was very fit for the steel slag. The comparisons of the dynamic shear properties of the steel slag with those of Nanjing fine sand and Fujian standard sand showed that the steel slag had similar dynamic shear resistance to Fujian standard sand and had potential to become a substitute for sand in the practical geotechnical engineering in the future. [ABSTRACT FROM AUTHOR]

• Steel slag and rubber particles are first proposed to be mixed into the mucky clay. • Dynamic shear properties of the MCSRA are significantly improved. • Steel slag content and rubber content have great effect on dynamic properties. • Hardin-Drnevich model could describe the dynamic performances of MCSRA well. • MCSRA could be applied to replace the mucky clay and Nanjing fine sand. To make full use of advantages of waste steel slag and old rubber particles, the steel slag and rubber particles were mixed into the mucky clay to form the mucky clay-steel slag-rubber particles admixtures (MCSRA) to improve the engineering properties of mucky clay. Dynamic tests have been carried out by resonant column apparatus to investigate the influence of steel slag content, rubber particle content, rubber particle size and confining pressure on small-strain dynamic shear properties of MCSRA. The results showed that the dynamic properties of MCSRA were significantly improved compared with those of the mucky clay. It also revealed that as steel slag content increased, the shear modulus increased and the damping ratio decreased. In addition, as rubber particle content and rubber particle size increased, the shear modulus decreased and the damping ratio increased, and as confining pressure increased, the shear modulus increased and the damping ratio decreased. Moreover, an improved dynamic model was built based on the Hardin-Drnevich model to describe the dynamic performance of MCSRA. By comparing the dynamic characteristics of MCSRA with those of the mucky clay-steel slag admixtures, the Fujian standard sand and the Nanjing fine sand, the MCSRA could be applied to replace the mucky clay improved with the steel slag and Nanjing fine sand in some practical engineering. [ABSTRACT FROM AUTHOR]