In Situ Evaluation of Unsurfaced Portland Cement-Stabilized Soil Airfields

The U.S. Army Engineer Research and Development Center (ERDC) was tasked to develop a method for the in situ evaluation of unsurfaced Portland cement-stabilized soil airfields. The ability of portable in situ strength and stiffness measuring devices to determine the material properties of stabilized soils was investigated using the Clegg hammer, dynamic cone penetrometer, soil stiffness gauge, portable falling-weight deflectometer, and portable seismic property analyzer. Regression and correlation analyses were performed to develop relationships between the in situ test device measurements and the unconfined compressive strength, modulus of rupture, repeated-load elastic modulus, and falling-weight deflectometer backcalculated elastic modulus of representative materials. Relationships proposed in previous studies were found ineffective, and a precise relationship for the determination of cement-stabilized soil material properties was not discovered. As a result of this study, it has been determined that further research is required for the development of an accurate cement-stabilized soil performance model.