Microstructural effects of environmental salinity on unbound granular road pavement material upon drying

• Published in: Acta geotechnica 2016-04, Vol.11 (2), p.445-451
• Main Authors: Liu, X. F., de Carteret, R., Buzzi, O. P., Fityus, S. G.
• Format: Article
• Language: English
• Subjects: Climate change; Complex Fluids and Microfluidics; Crystallization; Crystals; Engineering; Environmental effects; Foundations; Freeze drying; Geoengineering; Geotechnical Engineering & Applied Earth Sciences; Hydraulics; Land use; Mercury; Microstructure; Roads; Roads & highways; Salinity; Salt; Short Communication; Soft and Granular Matter; Soil salinity; Soil Science & Conservation; Solid Mechanics
• ISSN: 1861-1125; 1861-1133
• DOI: 10.1007/s11440-015-0393-9

Areas of high environmental salinity are predicted to increase over the next 40 years in Australia, due to land use and climatic changes. This presents a risk to road assets as accumulation of salts within roads has been found to cause damage to thin bituminous surfacings. It is in this context that the present study explores the microstructural changes caused by environmental salt crystals accumulating within unbound granular road pavements. Fine-grained specimens were prepared by static compaction, immersed in different solutions, and finally either freeze-dried or oven-dried at 40 °C. The effects of different drying procedures and salinity on soil’s microstructure were explored via mercury intrusion porosimetry and scanning electron microscope observation. Results suggest that a freeze-drying process can significantly modify the microstructure, which should be taken into account when conducting any microstructural analysis on high-salinity soil specimens.