Bio-stabilization of unconsolidated base materials (Abstract)
Rural roads in southwestern Manitoba and across Canada suffer from chronic rapid deterioration requiring expensive ongoing maintenance. The current research is an integral part of the initial attempt at stabilizing rural gravel roads with the introduction of aggregate gravel materials with a high content of reactive clays, organic catalysts, in conjunction with the use and application of appropriate construction protocols.
A one-mile test section of gravel road was reconstructed in the RM of Cornwallis where existing and new materials were sourced and analyzed to determine if they had the appropriate characteristics for the stabilization process. Once appropriate materials were obtained, the road was reconstructed using a mix of 32% clay and less than ¾” aggregate base along with the introduction of surfactants, organic enzymes and electrolytes via the soil stabilizing product known as EarthZyme. Road conditions were monitored before and after the successful reconstruction of the road using the dynamic cone penetrometer, nuclear densometer, Atterburgs Limit testing, and soil Proctor analysis. Test results indicated a reduction in dust of 77.3%, the bearing strength of the road improved by 51.47% after 20 days of vehicular use, and the density of the compacted material exceeded 100% of maximum dry density and continued to rise over the 21-day monitoring period. Visually, and analytically, the road performed exceptionally well after reconstruction by maintaining a hard dense surface with no visible plastic or elastic behavior, even when introduced to the heaviest of vehicular truck traffic. After the reconstruction of the roadbed surface, the only road maintenance required within a ~120 day period was one superficial grading without the addition of new materials, to which the road responded by quickly self-healing with subsequent vehicular traffic. Overall, a substantial improvement in the strength and durability of the road was and continues to be experienced, accompanied by a huge decrease in negative environmental impacts. In light of the substantial positive results of this initial research, further laboratory testing, test road construction, and monitoring is highly recommended.