# Particle Packing Optimization for CCR-GGBS-FA Binder Stone Waste pavement Base Material
## 2 Materials and Methods  
### Test Materials  
The materials used in this test were stone waste and CGF all-solid-waste binder. This study investigated stone waste material extracted from the stone waste mountain in Wulian County. Particle-size grading was performed on the original, as-received soil samples, as shown in Figure 2A. Stone waste with particle sizes less than 0.075 mm was categorized as stone powder, and waste with particle sizes between 0.075 and 4.75 mm was categorized as stone chips. After sampling, particle-size grading was performed on the as-received stone waste soil samples, and different particle sizes were identified via sieving, as shown in Figure 2A. The samples with different particle sizes were categorized as stone chips, fine stone dust, and ultrafine stone dust, as shown in Figure 3. The content of stone chips in the  
Figure 1: Particle packing theories. as-received stone waste accounted for 26.2% of the composition, fine stone dust accounted for 54.9%, and ultrafine stone dust accounted for 18.2%. Fine-grained particles smaller than 0.075 mm exceeded 70 percent of the total weight. The stone waste contains fine-grained soil type, with an inhomogeneity coefficient of 85, a curvature coefficient of 0.42, and poor gradation. The chemical and mineral composition of the stone waste is shown in Figure 4.  
The specific gravity of the stone waste is 2.68, the natural water content is 15.6%, the stone chips and fine stone powder have no plasticity, and the liquid and plastic limits of the ultrafine stone powder are 39.5% and 18.9%, respectively. The plasticity index of the stone waste is 20.6, which indicates the presence of clay with a low liquid limit. In summary, the Wulian County stone waste consists of poorly graded soil, which is characterized as fine-grained soil without plasticity. The SiO\({}_{2}\) content of the stone waste measured using the XRF test reached 68.19%, and the Al\({}_{2}\)O\({}_{3}\) content reached 15.23%. The diffraction pattern produced using X-ray analysis of the stone waste crystals was examined to analyze the atomic distribution pattern inside the crystals, and then the composition of the physical phase of the stone waste minerals was qualitatively and quantitatively analyzed. The raw data of the XRD pattern (Figure 4) of the stone waste sample were imported into Jade 6.0 software, and after searching/matching, it was determined that the main crystalline phase of the sample is quartz (SiO\({}_{2}\), PDF card no. 85-0796). Moreover, it was found that the sample contains sodium feldspar (Na(AlSi\({}_{3}\)O\({}_{8}\)), PDF#3-1658), calcium feldspar (Ca(Al\({}_{2}\)Si\({}_{2}\)O\({}_{8}\)), PDF#73-1435), and microplagioclase feldspar (KAlSi\({}_{3}\)O\({}_{8}\), PDF#19-0932). Figure 3: Particle-size distribution curves of each component of binder and test soil. Figure 2: Apparent state of stone waste and cementitious materials. (**A**) Apparent condition of stone waste. (**B**) Apparent condition of cementitious materials. These results establish that the mineral composition of the waste from the stone waste mountain in Wulian County is mainly quartz and feldspar. The CGF material consists of an alkali activator and pozzolanic material. The alkali activator consists primarily of calcium carbide slag (CCR), and the pozzolanic material consists of blast-furnace slag (GGBS) and fly ash (FA) (Figure 2B). CCR is a by-product of the hydrolysis of calcium carbide in the production of ethylene, with a pH value greater than 12.0, which provides an alkaline environment [7]. GGBS is the waste slag produced in the process of ironmaking, which is a highly reactive pozzolanic material. FA is the fly ash collected by the baghouse of a coal-fired power plant, which is a low-reactivity pozzolanic materials [7].