Improving the engineering behaviour of residual soil with fly ash and treated natural fibres in alkaline condition

ABSTRACT

This study explores the possibility of using sustainable materials in the form of fly ash as a precursor in alkali activation (AA) reactions, as well as coir fibres as discrete reinforcement. For enhancing the longevity of fibres in an alkaline environment and improving the mechanical performance of the soil–fibre composite, an effort was made in this study to physically coat the natural fibre surface with linseed oil and turpentine oil. The effect of surface treatment on coir fibres was initially analysed by field emission scanning electron microscopy and energy dispersive x-ray tests. To evaluate the effects, unconfined compressive strength, indirect tensile strength, and flexural strength tests were performed at 7 and 28 days of curing on AA-treated soil reinforced with treated and untreated coir fibres. The test results demonstrated that treated fibres significantly enhanced the mechanical properties of the AA-treated soil in terms of peak stress and post-peak behaviour.

KEYWORDS:

• Alkali activation
• coir fibre
• fly ash
• soil reinforcement
• mechanical properties

Acknowledgments

The authors wish to express their gratitude for the financial assistance provided by the Research Management Centre (RMC) of University Putra Malaysia under Fundamental Research Grant Scheme (No. 5524745) ‘Sustainable soil stabilization by olivine and its mechanisms’.

Disclosure statement

No potential conflict of interest was reported by the authors.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by the Research Management Centre (RMC) of University Putra Malaysia under Fundamental Research Grant Scheme [no. 5524745] ‘Sustainable soil stabilization by olivine and its mechanisms’.

Notes on contributors

Teingteing Tan

Teingteing Tan is a master student of Geotechnical Engineering at the Civil Engineering Department, University Putra Malaysia.

Bujang B.K. Huat

Bujang B.K. Huat is Professor of Geotechnical Engineering at the Civil Engineering Department, University Putra Malaysia.

Vivi Anggraini

Vivi Anggraini is Lecturer in Geomechanics at the Civil Engineering Discipline, School of Engineering, Monash University Malaysia.

Sanjay Kumar Shukla

Sanjay Kumar Shukla is Associate Professor of Civil Engineering at the School of Engineering, Edith Cowan University Australia.