About the research
Base stabilization additives are used to increase the strength and stiffness of road foundations in weak and susceptible soils. Numerous additives exist for improving performance of aggregate base layers, however, most independent studies have focused on non-proprietary additives. Additives are being used to stabilize base/subbase/subgrade layers, but engineering methods for pavement thickness design need to be better defined. In particular, determining granular equivalency (GE) factors for various proprietary geomaterial stabilizers will benefit the Minnesota Department of Transportation (MnDOT) and county engineers by establishing design parameter values and a means for comparing additive effectiveness and cost.
The research has three main goals: (1) evaluate the performance of selected proprietary additives by conducting laboratory and field tests; (2) prepare pavement designs and construction specifications based on the test results; and (3) analyze the benefits of additives in terms of pavement construction cost savings and long-term service life. The laboratory study will be based on ASTM/AASHTO/MnDOT test standards and designed to determine the relationships between strength, stiffness, moisture content, gradation, freeze-thaw durability, and leaching. The field testing will involve full-scale testbed construction using the most promising mix designs. Field testing will incorporate accelerated loading testing to evaluate performance of each test bed. The primary goals of this project will be to determine reliable GE factors for a variety of conditions and document performance, cost benefits, and life-cycle cost analysis. The outcome of this research will provide guidance for the selection of proprietary additives and optimized design for base stabilization of roads.