# Effects of Aging on the Dry Shrinkage Cracking of Lime Soils with Different Proportions
## 1 Introduction  
Lime soil, which is composed of lime, clay, quartz sand, and other materials, exhibits a compact structure, high strength, and good compatibility with ancient buildings [1; 2; 3; 4]. Particularly, lime soil is used in the construction of existing sites [5; 6; 7; 8; 9; 10]. Although the remediation of lime soil sites does not require high mechanical properties, the susceptibility of insufficiently aged lime soil to hydration results in a reduction in its internal moisture, which results in dry shrinkage cracking [11; 12; 13; 14]. Particularly, the alternating action of dry and wet cycles results in the generation of a large number of cracks and peeling to varying degrees, which adversely affect the stability and long-term preservation of earth sites [15; 16]. In addition, the durability requirements of newly restored soil sites [17; 18] reveal that the dry shrinkage cracking mechanism of lime soil is one of the key factors for analyzing the deterioration and disease prevention of soil sites. To improve the characteristics of lime soil and reduce the hydration of lime, the \"aging\" of lime soil has been tremendously investigated. For example, [PERSON] and [PERSON] explored the mechanism involved in the effect of aging time on the crystal transformation of calcium hydroxide (Ca(OH)\({}_{2}\))[19; 20]. In addition, [PERSON] and [PERSON] reported that the aging time affects the particle size and high reactivity of Ca(OH)\({}_{2}\), and can improve the mechanical properties, such as strength and hardness, of lime soil [21; 22]. Furthermore, [PERSON] investigated the effect of aging time on the size distribution and crystal formationof lime particles. The results revealed that an increase in the aging time of lime soil resulted in a change in the shape of Ca(OH)\({}_{2}\) crystal from a prismatic to a plate shape, which resulted in an increase in the average crystal particle size [23]. [PERSON] investigated the effects of water consumption during aging on the size distribution, chemical composition, and crystal formation of lime particles. The results revealed that the average particle size of lime decreased with an increase in water consumption; however, the water consumption of the lime particles had no significant effect on the Ca(OH)\({}_{2}\) and calcium carbonate (CaCO\({}_{3}\)) contents [24]. Moreover, it is worth noting that [PERSON] confirmed that increasing the aging time of lime soil samples can reduce pozzolanic reaction in the soil and improve their durability [25]. [PERSON] investigated the effects of factors, such as aging time and water to lime mass ratio, on the dispersion and activity of lime milk. The results revealed that the optimum water to lime mass ratio was 5:1. In addition, without aging, the Ca(OH)\({}_{2}\) produced by lime digestion exhibited good dispersion and high activity [26]. [PERSON] investigated the effects of aging time and lime content on the mechanical properties of lime-improved clay. The results revealed that the density and compressive strength of the lime soil samples decreased with increasing aging time. In addition, the aging time increased with increasing lime content, which reduced the plasticity index of the sample [27]. Moreover, an insufficient aging time resulted in the hydration reaction and expansion of calcium oxide (CaO), which resulted in the uplifting and cracking of lime soil [28; 29]. In addition, a long aging time and low lime activity affect the mechanical properties of lime soil [30; 31; 32]. These indicate that the reasonable aging time plays an important role in guiding lime soil construction technology. Current research on the aging of lime soil mainly focuses on the effect of aging on Ca(OH)\({}_{2}\) and engineering application; however, research on the mechanism involved in the aging process of lime soil under the combined effects of lime and soil is rare.