# Effects of Aging on the Dry Shrinkage Cracking of Lime Soils with Different Proportions
## 5 Conclusions  
In this study, the effects of the different aging time, lime content, and particle size on the dry shrinkage properties of lime soil were investigated using a dry-wet cycle, screening, and pH detection tests. In addition, the micro-scale change in the particle structure and the formation of new substances were analyzed using an SEM and XRD analysis, and the internal factors causing the micro-scale cracking of lime soil were discussed. The following observations were made in this study.  
1. The reasonable aging time of the samples can be determined by pH and particle size distribution. At the reasonable aging time, the pH of the samples exhibited a notable decreasing trend (the decreasing rate was 0.57-1.1%). Simultaneously, the contents of CaO and Ca(OH)\({}_{2}\) crystals in the sample decreased and gradually stabilized. The reasonable aging time can improve the particle agglomeration effect of lime soil. The decrease in the content of particles with a size of 0.01-0.1 mm was consistent with the increase in the content of particles with a size of 0.1-0.5 mm, and the difference in the particle size was 0-13%.  
2. At the initial aging stage, with an increase in the aging time, the volume crack and expansion shrinkage rates of the samples increased with the increasing lime content and particle size, decreased, and then stabilized. With an increase in the lime content, the aging time of the samples increased. In addition, with an increase in the aging time, the decline rate of the volume crack and expansion/shrinkage rates increased with the increasing lime particle size. Furthermore, the decline rate in the volume crack and expansion/shrinkage rates of the 20%-0.5-2 mm sample was higher than that of the 20%-0.01-0.074 mm, and 20%-0.074-0.5 mm samples.  
3. The reasonable aging times of the 10%-0.01-0.074 mm, 20%-0.01-0.074 mm, and 30%-0.01-0.074 mm samples were 48, 72, and 120 h, respectively. In addition, the reasonable aging times of the 20%-0.01-0.074 mm, 20%-0.074-0.5 mm, and 20%-0.5-2 mm samples were 72, 120, and 120 h, respectively. The research results provide a reasonable aging time for different proportions of lime soil. In addition, the moisture content, humidity, and temperature during the aging process all have an impact on the shrinkage and cracking of lime soil, and further research is needed.  
Funding acquisition, J.Y.; Writing--original draft preparation, Y.C.; Test design and implementation, Y.C.; Data curation, Y.C.; Put forward ideas, J.Y. and Y.C.; Writing--review and editing, J.Y., Y.C., S.W., X.Y., Y.Z. and L.Z.; Supervision, W.L., H.G. and H.S.; All authors have read and agreed to the published version of the manuscript.  
The research was supported by the National Natural Science Foundation of China (51978634), the Discipline Cultivation Project of Henan University (2019 ylzdcg05) and the Science and Technology Development Plan of Henan Province (212102310287, 212102310271).  
Not applicable.  
The data provided in this study can be obtained from the second author [PERSON].  
The authors declare that the work is original research that has not been published previously and is not under consideration for publication elsewhere. No conflicts of interest exist in the submission of this paper, and the paper is approved by all authors for publication.