Engineered Water Repellency for Mitigating Frost Action in Iowa Soils: Fid-Bau Portal

Engineered Water Repellency for Mitigating Frost Action in Iowa Soils

Brooks, Ty / Daniels, John L. / Uduebor, Micheal / Cetin, Bora / Wasif Naqvi, Mohammad

Organo-silane (OS) modification has been shown experimentally to render soil water repellent. Engineered water repellency has the potential for widespread use in geotechnical and geoenvironmental applications. One such application is mitigating the effects of frost action in susceptible subgrade soils, particularly for unbound, unsurfaced roads. As part of a larger project to evaluate the feasibility of post-construction treatment of such roads, testing was performed with two commercially available OS products at varying dosages. This paper summarizes experimentally observed relationships between treatment, apparent contact angle, and water entry head for four samples of frost-susceptible soil collected from different regions across Iowa. Soil water characteristic curves were used to estimate the prevailing pore size and to relate that to water entry head for a given sample. Modification with two different OS chemicals yielded apparent contact angles between 119° and 143°. The water entry head was determined to range from 15 to 63 cm of water. Inverse relationships were observed between average pore radius and water entry head. These results are expected to be useful to agencies interested in evaluating engineered water repellency for use in new construction as well as rehabilitation of existing infrastructure underlain by frost susceptible soils.