Study on the application of an activator for steel slag powder–cement in muddy soil

To solve the problem of steel slag casually discard polluting the environment and to simultaneously increase the strength of sea muddy soil solidified with ordinary Portland cement, steel slag powder (SSP) and cement are mixed into muddy soft soil to improve the curing effect. SSP has low activity levels, so it needs to be activated. Through laboratory testing, the SSP activity levels were stimulated using different accelerators. The results show that although silica fume can improve the unconfined compressive strength (UCS) of SSP-cement solidified soil, the excitation effect is not ideal at low concentrations. The best observed effect occurs when caustic soda (NaOH) is added. Na2SO4 can also stimulate the activity of SSP, but this effect is weak; therefore, this activator needs to be used in combination with other catalysts. As the curing time increases, the UCS of the sample shows a certain correlation with the water content. The X-ray diffraction patterns of the SSP-cement hydrate were investigated, and monosulphide calcium and sulphoaluminate compounds were found. The material structure is dense and can improve the strength of solidified soil.