Procedure for Evaluating Stabilization of Road Materials with Nontraditional Stabilizers

In response to the need to find cost-effective stabilizers, a large number of chemical products are being marketed as potential solutions. Traditional laboratory tests have not been able to predict the performance of these materials satisfactorily. A solution is for suppliers to construct experimental sections several hundred meters long. However, that becomes an expensive exercise, since each type of soil in a region would have to be used. An evaluation technique has been developed that allows test panels to be constructed in the field at low cost with a range of soils and stabilizers and that takes into account local environmental conditions and traffic. The aim of this paper is to present this evaluation technique and the results with a range of stabilizers and soils. The paper describes construction of the 1- × 3-m test panels and the subsequent testing protocol. Several materials, ranging from sandy to clayey, were tested with different generic stabilizers, such as polymers, enzymes, and ionic soil stabilizers. Control panels without additives were also constructed. The testing regime conducted over 8 months included regularly measuring the following: the in situ California bearing ratio with a dynamic cone penetrometer, both at the in situ moisture content and after soaking for 2 h; density and moisture; and permeability. Visual observations about performance were also noted. The test panel procedure is a cost-effective solution for evaluating the potential strength gain of stabilizers with a range of soils. As is known, stabilizers must be tailored to soil properties, because stabilizers do not all have the same effect.