Synthetic resins offer a possible method of soil stabilization for roads; aniline-furfural is a synthetic resin showing commercial possibilities. Differential thermal analysis is a useful tool for interpreting the relation between aniline-furfural and the soils that have been stabilized by this resin.

Differential thermal curves were run on several loess soils that had been stabilized with varying amounts of aniline-furfural. The clay fraction of these soils had previously been identified as predominantly interlayered illite-montmorillonite minerals. The <2 micron clay fraction varied from 7.4 to 37.0 percent. The thermal curves showed characteristic exothermic organic reactions in the treated soils and relationships were found between the thermal reactions, the percent aniline-furfural, and the percent clay.

Double peaks were observed on the curves of all soils containing 2 percent or more of aniline-furfural. The area under the organic double peaks was found to be a function of the percent aniline-furfural. The double peak is believed to be caused by initial burning of readily available aniline-furfural followed by final burning of the remaining aniline-furfural. The release of the resin responsible for the second peak may be due to a breakdown of the clay crystal structure at about 550° C. This indicates a close association of the resin and the clay minerals. The foregoing statement is further strengthened by a linear correlation of distance between peaks and the amount of clay present. Higher aniline-furfural contents increase the area under the second peak; this increase indicates that a larger amount of the resin is being utilized in cementation of grains and is reflected by the mechanical strength of stabilized soil specimens.