Cohesive Clays for Construction and Stabilization of Unpaved Roads

Cohesive clays and organic catalysts are tested and used for the construction and stabilization of the wearing surface of unpaved haulage and high-maintenance municipal roads in Manitoba. The process requires a typical A-base aggregate with good particle size distribution and a very high (>25%) fines and clay content. For this application, the inherent electronic bonding potential of natural reactive clay is harnessed to maximize clay to clay mineral bonding while limiting clay to water bonding and water ingress. Catalysts are used to promote densification, clay bonding with cationic polymers (present in natural soils and in the catalyst), and water egress. The result is a strong, semi-permanent clay cemented matrix that effectively bonds the aggregate mix. This produces a dense road surface with high bearing strength, superior durability, excellent road functionality, and low maintenance requirements. Only natural materials are used with no deletrious environmental impacts, and dust is reduced to a minimal level. An added benefit is the significant reduction in the use of high-quality aggregates, extending the life of known resources. Both high-traffic heavy haul roads and municipal roads have been construction and monitored in the Brandon region over the past five years, with no indication yet when the road surfaces will require a significant upgrading or reconstruction. This paper discusses the electronic bonding properties of clays, how and why the process works, the types of materials that can be used, road performance to date, and some of the applications where these types of roads can be very beneficial in terms of performance, cost and environmental impact.

Author

Mumin, Hamid

Session title

Green Technology in Geotechnical and Materials Engineering (PS)

Organizers

Soils and Materials Standing Committee

Category

Soils & Materials

Year

2020

Format

Paper

File

 


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