EFFECT OF HEATING ON SOME PHYSICAL AND CHEMICAL-PARAMETERS RELATED TO SOIL AGGREGATION AND ERODIBILITY
EFFECT OF HEATING ON SOME PHYSICAL AND CHEMICAL-PARAMETERS RELATED TO SOIL AGGREGATION AND ERODIBILITY
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DOI：
10.1097/00010694-198810000-00006
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发表时间：
1988-10-01
期刊：
影响因子：
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通讯作者：
GIACHETTI, M
中科院分区：
文献类型：
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作者：
GIOVANNINI, G;LUCCHESI, S;GIACHETTI, M
为了澄清的热浪，伴随着火的通道上的一些物理化学参数与土壤可蚀性的影响，我们进行了两种土壤，分类为桑迪壤土和粉质粘土，在受控条件下的人工加热。根据差热分析所测得的土壤中发生的真实热反应来安排加热程序。加热到220 ℃对有机物含量、粒度分布、塑性和液体极限只有很小的影响。超过这个值的有机质被烧毁，土壤失去了可塑性，质地砂部分增加。两种土壤的团聚体稳定性也不断增加时，公认的胶结剂，如凝胶形式，有机质，和有机金属水泥，被破坏。这意味着加热促进了新形式的胶结作用，其中铁和铝参与了与土壤红土化非常相似的过程。随着加热的增加，桑迪壤土的孔隙度连续降低，最明显的证据是对应于凝胶形式的脱水，相反，粉质粘土的孔隙度增加到460 ℃。在此温度下，孔隙率急剧下降，因为加热使粘土材料中的OH基团损失，粘土的内部结构坍塌。
To clarify the effect of the heat wave that accompanies the passage of a fire on some physicochemical parameters related to soil erodibility, we subjected two soils, classified as a sandy loam and a silty clay, to an artificial heating in controlled conditions. The heating program was arranged according to the true thermal reactions occurring in the soils previously detected by differential thermal analysis. Heating up to 220.degree.C had only little effect on organic matter content, particle-size distribution, and plastic and liquid limits. Beyond this value the organic matter was burned up, the soils lost their plasticity, and the textural sand fraction increased. The aggregate stability of both soils increased continuously also when the generally acknowledged cementing agents, such as the gel forms, the organic matter, and the organometallic cements, were destroyed. This means that heating promotes new forms of cementation in which iron and aluminum are involved in a process very similar to soil laterization. The porosity of the sandy loam soil decreased continuously, as the heating increased, the clearest evidence of this being in correspondence of the dehydration of the gel forms, on the contrary, the porosity of the silty clay soil increased up to 460.degree.C. At this temperature the porosity sharply decreased, because the heating produced the loss of the OH groups from the clay materials and the internal structure of the clays collapsed.