Research on the Mechanism and Prevention Methods of the Drying Shrinkage Effect of Earthen Sites

Abstract

In view of the fact that it is easy for the ancient city soil site of Cai Kingdom to expand and crack when encountering water, this paper explores the methods to improve the expansion and shrinkage deformation, dry shrinkage cracks and easy water absorption characteristics of the expanded site soil based on a lime and silicone hydrophobic agent. In this paper, the expansive clay in the old city site of Cai Kingdom in Zhumadian was taken as the research object, and the dry-shrinkage fissure test of saturated expansive soil was carried out, to study the influencing factors of the dry-shrinkage cracking of expansive soil in this area. The site soil was modified with lime and glue powder, and the fissure image was quantitatively analyzed by MATLAB. The test shows that the smaller the particle size, the faster the evaporation of water and the smaller the surface fissure rate; the thicker the thickness of the soil sample, the greater the surface fissure rate and the greater the crack width; and with the increase in the number of drying and wetting cycles, the surface fissure rate of the soil sample increases. In this paper, lime and waterproof materials are used to improve the expansive soil. This not only reduces the dry shrinkage crack rate, but also improves the waterproof performance and durability of expansive soil.

Experimental Study on the Cracking and Mechanical Properties of Lime Soil with Different Slaking Conditions of Newly Repaired Earthen City Walls

“…Lime and soil are mixed to form lime soil, which has the characteristics of high strength, good integrity, economic material and convenient construction [1,2]. As a repair material, lime is widely used to improve the mechanical properties of rammed soils in the restoration of ancient rammed earth projects [3][4][5][6][7][8][9][10][11]. However, due to the differences in external environment, material composition and construction technology [12][13][14][15][16][17], a large number of cracks, flakes and other diseases often appear on the outer surface of earthen city walls repaired with lime soil.…”

The Impact of Microwave Drying on the Structure of Exemplary Soils—Insights Using X-ray Microtomography

“…Different soil drying methods can have various effects on the structure and, thus, on the geomechanical and filtration features (thermally induced thermo-hydro-mechanical behavior of saturated or unsaturated soils [ 1 , 2 , 3 ]). The rapid change in conditions can affects the soil fabric [ 4 ] and therefore, it can weaken the soil grains or solid material, leading to cracking, fracturing, and crushing.…”