Alkalinity production is one of the most typical and widespread salinization hazards on the Loess Plateau. Based on the characterization of typical flooding sites and the results of salt monitoring, this study investigates the deterioration mechanism of salinization on Zhouqiao site. The orthogonal test was used to simulate the effects of different concentrations of MgSO4, NaCl and CaCl2 under natural conditions on the quality change, salt analysis out location, surface phenomenon, strength and electrical conductivity of the soil at the Zhouqiao site, and to make a preliminary analysis on the mechanism of saline deterioration of the site soil. The results show that the soil column mass increased significantly under the action of salt, and the rate of salt absorption in the soil column decreased when the critical value was reached, and the critical values were different under the action of different kinds of salts. The rate of salt analysis is also influenced by the salt concentration and the number of cycles, which gradually increases with the increase of salt concentration and the number of cycles. The nominal strength of the soil column with the number of cycles, but occasionally increases. The conductivity increases with the number of cycles, and the magnitude distribution of the conductivity of the soil column under the action of different salts is not exactly the same.
The reciprocating action of the external environment gradually reduces the mechanical properties and water stability of original heritage buildings, resulting in the gradual loss of their cultural value. In this paper, the adobe for the construction of raw soil and cultural relics in western Henan is taken as the research object. The local plain soil is used as the raw material, and the adobe samples are prepared with modified materials such as quicklime and sodium methyl silicate, in order to improve its mechanical properties and water stability. The degree of correlation between the compressive strength, capillary water absorption, pH value, particle size distribution, and the electrical conductivity of modified raw adobe, as well as the modification mechanism of the microstructure, was studied. The results show that the addition of quicklime and sodium methyl silicate can enhance the compressive strength and water resistance of the modified raw adobe, and the optimum dosage is 1.5% sodium methyl silicate; with the increase of the curing age, the compressive strength of the single-mixed quicklime sample, the single mixed sodium methyl silicate samples, and the composite sample were increased by 1.94 times, 12.6 times and 2.61 times, respectively, compared with the plain soil samples, and with the increase of compressive strength, the pH, conductivity and capillary water absorption of the samples decreased continuously. It is evident from the particle gradation test and SEM images that the internal pores of the samples in the modified group become smaller, and the particle structure of the sample doped with sodium methyl silicate is the densest. The results of the study provide support for the restoration of the soil and cultural-relic buildings.
Due to the special geographical location, climatic characteristics, special soil properties and the flood zone of the Yellow River in Kaifeng, the groundwater level in the lower reaches of the river basin is high and contains much salt. The matrix suction and surface free energy of the Kaifeng city wall earthen site changed under capillary action, resulting in cracking, peeling and efflorescence to varying degrees. In order to reduce the deterioration of the Kaifeng city wall caused by environmental erosion, a select lime with excellent mechanical properties and waterproof methanesiliconic acid sodium salt with excellent water resistance were chosen to reinforce the earthen sites. In this paper, 0%, 3%, 5% and 7% lime, and 0%, 1%, 2% and 3% waterproof materials were selected to determine four types of imitation site soil with 16 different mix proportion samples. Further, samples with different mixing ratios were subjected to direct shear, a disintegration test, and a microscopic scanning electron microscope test. The results show that under different normal stresses, with the increase in waterproof material content, the growth rate of shear strength of imitation site soil ranges from 1.82% to 10.81%. With the increase in lime content, the shear strength of imitation site soil increases rapidly, up to 38.16%. Both materials can improve the shear strength of the soil site. Under reinforcement with the two materials, the cohesive force of the imitation site soil can be improved at a maximum rate of 59.23%, and the internal friction angle changes in the range of 36.72°–41.61°. Compared with the sample without waterproof material, the mass water absorption rate of the sample with waterproof material decreases in the range of 2.76–27.77, and with the increase in waterproof material, the mass water absorption rate of the sample gradually decreases. The chemical reaction products of the waterproof materials and lime can play a filling role in silty clay; filling micro-pores and micro-cracks between soil particles.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.