Electrokinetics to modify volume change characteristics of expansive soils: a laboratory based investigation

Author(s): Samudra Jayasekera
Paper category: Proceedings
Book title: Proceedings of the International RILEM Conference on Materials, Systems and Structures in Civil Engineering Conference segment on Electrochemistry in Civil Engineering
Editor(s): Lisbeth M. Ottosen
ISBN: 978-2-35158-176-6
e-ISBN: 978-2-35158-177-3
Publisher: RILEM Publications SARL
Publication year: 2016
Pages: 170
Total Pages: 1
Language : English

Abstract: Volume change characteristics of expansive soils can cause significant structural damages to built infrastructure, particularly significant in long term performance of road pavements. The objective of this study was to investigate the potential of electrokinetic processing techniques to stabilise volume change characteristics of expansive soils. The investigations were carried out in the laboratory using soil collected from Horsham, Victoria, Australia, a well-known region for highly reactive soils, causing significant damages to road pavements. A layer of soil was placed in glass tanks and compacted to a known density and water content typical of field conditions. Using electrodes inserted into the soil, a direct current was passed across the soil under different voltage gradients varying between 0.25 to 2.0 V/cm for periods of 7, 14, 30 & 60 days. After electrokinetic processing, soil specimens were tested for volume change properties using soil reactivity indicators such as consistency limits, linear shrinkage, free swell index, shrink-swell index and activity. The test results show that with electrokinetic treatments, the volume change potentials of the experimental soil reduced to a greater or lesser degree depending on the magnitude of the voltage gradient and processing time. Under certain voltage gradients and treatment durations, experimental soil transformed from extremely reactive status to a slightly or almost non-reactive condition. In general, higher voltage gradients produced more rapid results in reducing volume change potentials however, they also lead to detrimental processes such as excessive drying, shrinking and cracking of soil, thus devaluing the merit of the treatment. The experimental results suggest the potential of developing electrokinetic treatment technique to stabilise volume change properties of expansive soils effectively and efficiently.

Online publication : 2016
Publication type : full_text
Public price (Euros) : 0.00