The benefits of subgrade lime stabilization are incorporated, for the first time, into the design of a major interstate highway pavement in Pennsylvania. The project comprises widening and complete reconstruction of 21 km of the Pennsylvania Turnpike in Somerset County. Field explorations indicated that the subgrade is fairly homogeneous and consists primarily of medium to stiff clayey soils. To safeguard against potential softening due to rain, lime modification has been traditionally utilized as a construction expedience for highway projects with clayey subgrade. Such an approach, however, does not take advantage of the added strength of the lime-stabilized subgrade in pavement design. Lime improves the strength of clay by three mechanisms: hydration, flocculation, and cementation. The first and second mechanisms occur almost immediately upon introducing the lime, and they have been investigated in the study; the third is a prolonged effect. Laboratory tests were performed to accurately capture the immediate benefits of lime stabilization for design. Both treated and natural clayey samples were subjected to resilient modulus and California bearing ratio testing. To prevent cementation, the lime-treated specimens were not allowed to cure. Nevertheless, they showed significant increases in strength, which, when incorporated into design, reduced the pavement thickness and resulted in substantial savings.
Incorporating Subgrade Lime Stabilization into Pavement Design
Transportation Research Record
2000-01-01
Article (Journal)
Electronic Resource
English
Lime Stabilization of Railway Track Subgrade
British Library Conference Proceedings | 1997
|Evaluation of Structural Contribution of Lime Stabilization of Subgrade Soils in Mississippi
Transportation Research Record | 2001
|Subgrade Criteria for Airport Flexible Pavement Design
British Library Conference Proceedings | 1997
|