Use of Stabilized Lateritic and Black Cotton Soils as a Base Course Replacing Conventional Granular Layer in Flexible Pavement

• Published in: International journal of geosynthetics and ground engineering Vol. 6; no. 1
• Main Authors: Amulya, S., Ravi Shankar, A. U.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 2020; Springer Nature B.V
• Subjects: Aluminosilicates; Aluminum; Ambient temperature; Base course; Building Materials; Calcium aluminum silicates; Calcium ions; Calcium silicate hydrate; Compressive strength; Cotton; Crystal structure; Curing; Engineering; Environmental Science and Engineering; Fatigue life; Flexible pavements; Flexing; Foundations; Geoengineering; GGBS; Granulation; Hydraulics; Original Paper; Silicon dioxide; Sodium hydroxide; Sodium silicates; Soil analysis; Soil investigations; Soil stabilization; Soil stresses; Soils; Black cotton soil; Durability; Alkali solutions; Microstructure; Lateritic soil; Stress–strain analysis
• ISSN: 2199-9260; 2199-9279
• DOI: 10.1007/s40891-020-0184-8

The present work investigates the improved properties of lateritic and black cotton soils stabilized with ground granulated blast furnace slag (GGBFS) and alkali solutions. The alkali solution includes a mixture of sodium hydroxide and sodium silicate. The lateritic and black soils are treated with 30% GGBFS and the alkali solutions consisting of 6% Na
2
O having silica modulus (
Ms
) of 0.5, 1.0 and 1.5 at a constant water binder ratio of 0.25. The treated samples were air-cured for 0 (immediately after casting), 3, 7 and 28 days at ambient temperature. The treated lateritic soil with 0.5 and 1.0
Ms
is found durable after 3, 7, and 28 days curing. Whereas, the treated BC soil found durable with
Ms
0.5 at modified Proctor density after 28 days curing. The formation of calcium silicate hydrate and calcium aluminosilicate hydrate structures resulted in a remarkable improvement of compressive strength, flexure and fatigue life of treated soils due to dissolved calcium ions from GGBFS, silicate and aluminium ions from alkali solutions. The microstructure image of the durable soil sample shows the crystal orientation of particles. The design of high and low volume roads is proposed by replacing the conventional granular layer with the durable stabilized soil and stress–strain analysis is carried out using pavement analysis software.