## 6 Conclusions  
This study mainly shows the influence trend of the compressive strength and resistivity of adding desulfurization slag to the CLSM and the optimal content of DS addition replacements and, according to relevant ASTM specifications, the fine aggregate of the CLSM material was replaced with desulfurization slag with a replacement proportion of 0-50% to test the compression strength and surface resistance of the CLSM under different curing times (1-120 days). After summarizing the test results, we tried to predict the trend of the compressive strength and surface resistivity based on a mathematical model to establish a good prediction model to provide a reference for future research and engineering applications. The research results are summarized as follows:  
1. The test results show that the compressive strength of the CLSM is inversely related to the replacement amounts of DS. When the replacement proportion of the DS increases but less than 20%, the compressive strength decreases rapidly with the increase of the replacement DS. When the replacement ratio of the DS is between 20% and 50%, the reduction in the compressive  
Figure 18: (**a**) Comparison of the predicted analysis and test results for the relationship between the compressive strength and surface resistivity (by curve graph). (**b**) Comparison of the predicted analysis and test results for the relationship between the compressive strength and surface resistivity (by histogram). (**c**) Comparison of the predicted analysis and test results for the relationship between the compressive strength and surface resistivity (hyperbolic function model). (**d**) MAPE value by applying the predicted analysis of the compressive strength and surface resistivity (hyperbolic function model). strength value does not change much at any curing age. For the compressive strength on the 28 th day, if the average amount of desulfurization slag replacement increases by 10%, the compressive strength is reduced by 0.9 MPa. Therefore, the 20% DS fine aggregate replacement proportion is a key recommended amount for the compressive strength of CLSMs. 2. From the test results, the surface resistivity of the CLSM is inversely related to the replacement amount of the DS and directly proportional to the curing time. When the replacement proportion of the DS increases and exceeds 10%, the surface resistivity decreases rapidly with the increase of the replacement DS. When the replacement ratio of the DS is between 0% and 10%, the reduction in the surface resistivity value does not change much at any curing age. For the surface resistivity on the 28 th day, if the average amount of desulfurization slag replacement increases by 10%, the surface resistivity is reduced by 0.9 k\(\Omega\)-cm. Compared with the surface resistivity development of the previous 28-day value, it is most significant at the age of 28 to 56 days. The possible reason is that the hydration of the CLSM is completed in the late period, which increases the percentage of the resistivity value growth. Therefore, the 10% DS fine aggregate replacement proportion is a key recommended amount for the surface resistivity of CLSMs. 3. Based on mathematical functions, this study explored the combined design of CLSMs and DS. We deduced, under a fixed water-binding rate (w/b = 1.5), various variables such as the change of the curing ages and the replacement proportions of fine aggregates by desulfurization slag, the prediction model of the compressive strength, and the surface resistivity of CLSMs. This provided future engineering design references for waste recycling and reuse. 4. Inferring from the test results, the relationship between the different curing ages and replacement rates of the desulfurization slag and compressive strength is a hyperbolic function model, and the relationship with the surface resistivity is an exponential function.