Behaviour of enzymatic soil stabilization at elevated temperatures using advanced micro structural investigations

ABSTRACT

Soil moisture variation plays a key role in maintaining the engineering properties of soils. One of the main factors that impact the soil moisture content is the temperature, which has a strong impact to change the initial or design moisture and results in significant soil volume changes. This study aims to investigate the effects of temperature on the performance of enzymatically stabilised soils. The enzyme used in this study is Eko-soil and the soil used is clayey silt of low plasticity (ML). The mechanical behaviour was first assessed through the unconfined compression strength and weight measurements based on samples exposed to a series of operational temperatures. X-ray μCT tomography images were then used to assess the microstructure. Porosity, size and geometrical shape of the pores were analysed at elevated temperatures. Results revealed that the enzyme is effective in maintaining the initial pore structure under the tested temperature range.

KEYWORDS:

• Enzyme
• soil stabilisation
• X-Ray μCT
• temperature variation
• soil volume changes

Acknowledgments

This research was conducted by the Australian Research Council Industrial Transformation Research Hub for nanoscience-based construction material manufacturing (IH150100006) and Transformation of Reclaimed Waste Resources to Engineered Materials and Solutions for a Circular Economy (IH200100010). The X-ray facility and Microscopy & Microanalysis facility provided by RMIT University is acknowledged.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The work was supported by the Australian Research Council [IH150100006 & IH200100010].

Notes on contributors

Amir Sidiq

Dr Amir Sidiq is a Research Fellow at RMIT University, Australia. He obtained his first degree in 2012 followed by his Master’s degree in 2016 and Ph.D. degree in 2021 at RMIT University. He has 2 years of industrial experience in geotechnical engineering in Australia and has conducted multidisciplinary research works. His research areas are construction materials investigation, structural design, asset management and structural digital twin development.

Dilan J. Robert

Dilan Robert is a Chartered Civil Engineer and an Associate Professor in Engineering at RMIT University. He obtained his first degree (2005) from University of Moratuwa, Sri Lanka, and the PhD degree (2011) from University of Cambridge, UK. His research areas include road pavements, soil stabilisation, soil–structure interaction analysis, offshore geotechnics, unsaturated soils and waste recycling in construction. He is a Fellow of Engineers Australia and has over 20 years experience in geotechnical and underground infrastructure projects.

Brian O’Donnell

Mr. O’Donnell is the Chief Executive Officer of Center for Pavement Excellence Asia Pacific (CPEAP), established to provide standards and guidance on innovative stabilisation techniques for road pavements. His career spans more than 50 years in local government, culminating as a City Engineer/City Planner at municipalities in Melbourne Australia, and his interest in design of pavements commenced in 1970 when he had to manage highly reactive clays for constructing roads. He has been recently awarded a Shobhit University Honorary Doctorate for Research.

Susanga Costa

Dr Susanga Costa is a senior lecturer in geotechnical engineering at Deakin University, Australia. He completed his PhD in geomechanics from Monash University Australia. He has expertise in expansive soil behaviour, fracture in clay soils and soil stabilization. Dr Costa’s research interests include use the reclaimed and recycled waste for soil stabilization, mitigation of desiccation cracks, application of microbial calcite precipitation to fine grained soils and impact of climate change on shallow ground.

Sujeeva Setunge

Sujeeva Setunge is the Associate Deputy Vice Chancellor Research and Innovation for Science, Engineering and Health at RMIT University in Melbourne, Australia. She is the director of the ARC research hub on transformation of reclaimed resources to engineered materials and solutions for a circular economy (TREMS). She leads other large multidisciplinary research projects in the areas of climate resilience, digital twins of infrastructure, smart cities and zero emissions. Professor Setunge is a Fellow of Engineers Australia and a chartered professional engineer.

Usha Iyer-Raniga

Professor Usha Iyer-Raniga is at the School of Property and Construction Management, RMIT University. Usha was co-lead of the UN’s One Planet Network’s Sustainable Buildings and Construction Programme (SBC), where the work directly impacted SDG 11 on Sustainable Cities and Communities and SDG 12 on Responsible Consumption and Production. She is on the editorial board for refereed journals and has led Special Issues. Usha serves on the Boards of various not for profit organisations and has also served as panel judge for state, national and international awards.