Strength properties of dredged soil at high water content treated with soda residue, carbide slag, and ground granulated blast furnace slag

Abstract

In this study, three industry by-products, soda residue (SR), carbide slag (CS), and ground granulated blast furnace slag (GGBS), were used to stabilize dredged soil at high water content. Based on the orthogonal test design, unconfined compressive tests were conducted to analyze the strength of stabilized soil cured for 3, 7, and 28 days. The drying–wetting durability of the stabilized soil was also investigated. The results indicate that the increase in GGBS dosage can increase the unconfined compressive strength (UCS) of samples with an initial water content of 110%, and the optimum dosages of SR and CS were 35% and 6%, respectively. The order of effect of the factors for the 3-day UCS was SR > GGBS > CS, which changed to GGBS > CS > SR for the 7-day and 28-day UCS. The results of X-ray diffraction (XRD) and scanning electron microscopy (SEM) show that the main products of hydration in stabilized soil were ettringite, calcium chloroaluminate hydrates (Fs), and gismondite. The reaction involving SR, CS, GGBS, and soil minerals produced the above hydration products, which had the filling-in and cementation effects. In general, 5 cycles of drying–wetting had no adverse effect on the USC for dredged soil stabilized with SR-CS-GGBS mixtures. The results provide a theoretical basis and data support for the resource utilization of SR, CS, and GGBS as stabilizer for dredged soil at high water content.