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| Distribution and function of cementing materials of soil aggregates on the Loess Plateau, western China |
| Zhang Yaofang1,2, Zhao Shiwei1,3, Wang Zilong1,2, Li Xiaoxiao4, Li Mingrui1,2, Du Can3 |
| 1.Institute of Soil and Water Conservation, Chinese Academy of Scinences and Ministry of Water Resources,712100,Yangling,Shaanxi,China; 2.University of Chinese Academy of Sciences, 100049, Beijing, China;3.Institute of Soil and Water Conservation, Northwest A & F University, 712100, Yangling, Shaanxi, China;4.People's Government of Jiaocun Town of Lingbao City, 472501, Lingbao, Henan, China |
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Abstract Cementing materials are the foundation and key component of the formation and stability of soil aggregates. Combining with the regional characteristics of cementing materials of soil aggregates on the
Loess Plateau, western China, this paper reviews the existing aggregates forming theory and the functions of cementing materials in the process of aggregate formation. The typically regional characteristics of the cementing materials distribution in the soil aggregates of the Loess Plateau are summarized. The clay content is rare with considerably different spatial distribution, and decreases as it goes deeper along the soil profile. The calcium carbonate content, which is around 10% in most area, increases at first and then decreases as it goes deeper along the soil profile. The organic carbon content decreases when it goes from the southeast to the northwest and from the surface to deeper inside. The main problems include: the differences of the cement type in the process of aggregates formation,and the lack of systematic and targeted research on the specific mode and intensity of action of different cements as well as the bonding mechanism of cementing materials. Therefore, the corresponding research directions are proposed.According to the regularity of the cementing materials in the soil profile, future researches should be focused on cementing process, strength and mechanism of three kinds of soil aggregates,which are organic carbon as the main cementing materials on the humus layer, the interaction of organic carbon and calcium carbonate cementing material on the transition layer, and calcium carbonate as the main cementing materials on the illuvial layer.
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Received: 27 May 2014
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