Effect of fine sand powder on the rheological properties of one-part alkali-activated slag semi-flexible pavement grouting materials

Understanding the rheological properties of one-part alkali-activated slag grouting material(OAASGM) are very significant when it used as a semi-flexible pavement (SFP) grouting material. The fluidity, setting time, rheological properties, mechanical properties, grouting saturation, and Marshall stability of OAASGM with different content of fine sand powder were systematically evaluated. The results showed that fine sand powder can effectively prolong the setting time and improve the rheological properties of OAASGM. When the added amount of fine sand powder was 10% (OAASGM-10), the fluidity was 14 s, the operability time was 45 min, and the initial yield stress and plastic viscosity of OAASGM were 0.699 Pa and 1.997 Pa.s, respectively. Furthermore, it had the characteristics of shear thinning, so it did not bleed water segregation. The grouting saturation of the OAASGM-10 was as high as 91.89%, the Marshall stability of the corresponding composite material was 31.31 kN, and the flow value was 3.055 mm. These results meet the technical requirements of semi-flexible pavement (SFP), which are expected to be an alternative for cement as a SFP grouting materials.