STABILIZER MECHANISMS IN NONSTANDARD STABILIZERS

An improved understanding of the mechanism of nonstandard chemical stabilizers is sought in the mineralogy and chemistry of clays and stabilizers. The mineralogy of clays and the chemistry of stabilizers are described. The complete hydrolysis of the rock mineral feldspar produces the rock minerals opaline and gibbsite. This pathway provides a most probable route for the chemical stabilization process. In the natural weathering process, the presence of alkali metal cations prevents completion of hydrolysis and results in an end product of clay minerals except where lateralization occurs. The process of lateralization is paralleled by the effects of chemical stabilizers. Certain organic ring compounds provide a strong attraction for metal cations. Chemical stabilizers contain these compounds in ionized form so that they can remove cations from the clay environment and permit the hydrolysis to proceed to a stage of lateralization. In a certain construction procedure involving injection, development of a high electrochemical potential results in rapid infiltration through normally impervious clays. In another construction procedure limited to scarification, the developed potential is low, and mixing is required. For either procedure, the behavior of resulting stabilized materials resembles that of natural concretions in various stages of lateralization, and the materials are resistant to moisture penetration and frost action. Strength increases with density, which results in higher intermolecular attractions. The physical manifestation of the proposed mechanisms at work has frequently been observed in the case studies, which are referenced in detail for illustration. A review of recent case studies and some supporting laboratory data are provided.