## 5 Conclusions  
The present study focuses on the effect of seven different particle gradation types of NSLA on the performance of AN-LAC and analyzes the influence of different pre-treatment methods for aggregate on the shrinkage of concrete. Through the mechanical test, drying shrinkage test, and SEM test, this study can fill the gap in the current literature on the effect of characteristics of NSLA, such as particle gradation and water absorption, on the performance of LWAC, to a certain extent. In addition, this paper can also establish the modified elastic modulus prediction model of AN-LAC considering the effect of the particle size of NSLA, which provides theoretical support for the relevant research. The primary conclusions are as follows:  
1. The compressive strength, splitting tensile strength, and flexural strength of AN-LAC at 3 d, 7 d, and 28 d showed an increasing trend when the average particle size decreased. The compressive strength of AN-LAC-4 and AN-LAC-3 at 28 days reached the maximum value of 56.7 MPa and minimum value of 43.7 MPa, respectively. The main reason is that NSLA with a smaller particle size was important for AN-LAC to have reliable particle size distribution and possess excellent packing. Moreover, compared with ceramics concrete, AN-LAC possessed better toughness;
2. Under axial compressive loading, the failure modes of all groups were shear failure. AN-LAC containing NSLA with a small particle size exhibited improved elastic modulus. The prediction results of the elastic modulus models of LWAC were closer to the experimental data than that of OPC concrete. Based on the existing models, the modified elastic modulus prediction model of AN-LAC was established considering the effect of particle size of NSLA;
3. The NSLA, which was modified by using a silicone hydrophobic agent and pre-wetted by soaking in water, respectively, could enhance the strength of AN-LAC at 28 days. The compressive strength and splitting tensile strength of the concrete with modified NSLA were higher than that of the concrete with pre-wetted NSLA;  
Figure 15: The characteristics of the ITZ of AN-LAC: (a) AN-LAC-1N; (b) AN-LAC-1S; (c) AN-LAC-1W.  
* The shrinkage rate of the concrete with pre-wetted NSLA and modified NSLA at 90 days was 17.7% and 10.3% lower than that of the concrete with untreated NSLA, respectively. According to the microscopic morphology of the ITZ, these pre-treatment methods could significantly reduce the number and length of cracks around the NSLA.  
Conceptualization, P.D.; writing--original draft preparation, X.Z.; writing--review and editing, W.B.; supervision, J.G.; validation, D.C. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The data presented in this study are available on request from the corresponding author. The data are not publicly available due to the privacy of the data.  
This investigation was carried out in Shandong Provincial Key Laboratory of Civil Engineering Disaster Prevention and Mitigation, Shandong University of Science and Technology, Qingdao-266590, China.  
The authors declare no conflicts of interest.