Gaining access to remote projects in challenging terrain is a significant task that requires careful consideration during renewables construction process..
There’s a growing demand for materials that can withstand heavy traffic, require minimal maintenance, and minimise environmental impact, while also ensuring workers’ safety.
For industries striving for sustainability, there’s a growing need to find new ground with innovative solutions.
Composite mats, originally developed for temporary access in remote and challenging environments, are now gaining attention and have proven their ability to tackle common geotechnical challenges.
At the 18th East Asia-Pacific Conference on Structural Engineering and Construction (EASEC-18), Griffith University researchers Hassan Karampour, Shelley Karkoodi, and Barry Kok presented their groundbreaking findings.
* Their study, ‘High Performing Lightweight Flexible Honeycomb Sandwich Geomats’, evaluated how composite mats – constructed from high-density polyethylene (HDPE) with a honeycomb core – performed under the extreme conditions.
The results validated the design’s performance in extreme settings and revealed its transformative potential across a wide range of industries, including energy, civil construction, defence, and beyond.
Rethinking ground engineering
For decades, reinforced concrete, steel, timber and geotextiles have been the go-to material for many construction needs, especially in road infrastructure, access ways, and high-traffic areas.
Due to the increasing demand on these assets, the performance of conventional solutions has come under scrutiny.
For instance, serviceability issues such as excessive deflections over time requires extensive maintenance to keep it functional.
These issues lead to high operational costs, costly downtime for repairs, and concerns about safety and stability on active construction sites.
Moreover, the conventional options involve significant environmental costs, including high CO2 emissions, which are a growing concern in industries striving for carbon reduction and sustainability.
This conventional approach to ground engineering is further challenged in locations with difficult terrain or stringent environmental standards.
Soil disturbance, contamination risks, and ecological impacts of traditional materials can hinder project timelines, increase costs, and negatively impact communities surrounding construction sites.
As industries push the boundaries of traditional practices, composite mats are emerging as a versatile, economical, and sustainable solution for temporary access and soil stability challenges.
A researcher’s journey
Kok, a 26-year veteran in the geotechnical field and industry researcher, first encountered Dura-Base, a heavy-duty composite mat system, in 2016.
Initially, it did not pique his interest — until a few years later when he faced a project with a tight construction timeline in an environmentally sensitive area.
Traditional methods offered no viable way to lay temporary access while ensuring timely ground reinstatement.
Kok needed a modular, quick-fix solution, and Dura-Base perfectly bridged the gap.
“As a designer, I design and explore different solutions based on their merit. Composite mats are semi-rigid, and this is the perfect solution for problematic soil and poor sub-grade,” Kok said.
“Concrete, timber and steel are strong but when these fail, it is catastrophic. At the other end of the spectrum are flexible options like geo-fabrics which will result in unacceptably uneven ground.”
One defining moment for Kok came while observing a team pour concrete for a temporary road.
He firmly believed that the large construction footprint was a waste of resources and had an unnecessarily heavy impact on the environment.
Furthermore, the subsequent rehabilitation efforts, including concrete removal, disposal, and ground restoration, highlighted the wastefulness and high costs associated with traditional methods.
Kok emphasised that Dura-Base’s potential to save significant time and money, particularly on semi-permanent structures used on large scale projects, which are often costly and prone to delays — sometimes amounting to millions of dollars.
Although Dura-Base has been on the market for some time, its potential in geotechnical applications remains underexplored, with few studies investigating its limitations.
Tested and proven resilience
To validate their durability, the Griffith University research team subjected composite mats to a series of rigorous mechanical tests.
Specifically, the Dura-Base heavy-duty matting system was selected for the tests due to its reputation in the market.
Compression tests demonstrated their ability to bear heavy loads without compromising structural integrity, while shear and bending analyses revealed their resilience under dynamic stresses.
The mats’ performance under extreme conditions was further simulated using finite element analysis (FEA), which assessed their interaction with various subgrade materials.
The results confirmed the mats’ ability to uniformly distribute concentrated loads through the honeycomb structure, reducing localised stress points and preventing ground failure.
The real-world trials were equally compelling. In active operations, where mats faced heavy machinery and repetitive wear, they not only retained their performance but also exhibited strain hardening — a process where materials strengthen under repeated loading.
This durability translates to extended service life and lower long-term costs, adding to the composite mats list of economic benefits.
Engineered for strength and versatility, their lightweight honeycomb structure efficiently distributes loads across all ground types, especially low strength soils, while remaining easy to manoeuvre and install.
Designed to withstand the harshest of environments, they perform reliably under diverse environmental conditions, making them an ideal choice for modern infrastructure projects.
Real-world solutions
Since Kok’s initial introduction to the composite matting system, he has witnessed its effectiveness in numerous real-life scenarios while working on multiple energy and road infrastructure projects as a geotechnical advisor.
He noticed that their flexibility allows the mats to adapt to minor ground movements without cracking — an advantage which rigid materials simply cannot match. By providing a stable, load-bearing surface with minimal soil disruption, composite mats also help mitigate the ecological impact on the ground, protecting grass roots and lessening the risk of erosion and reducing the risk of contamination.
This versatility has seen the deployment of mats beyond temporary roadways, with an increase in geotechnical applications such as working platforms.
A crane lift platform that may have required weeks of clearing topsoil and compacting with fill material, could potentially be replaced by laying out a truckload of mats.
Once removed, the mats leave the ground largely undisturbed, allowing for faster recovery and reducing the need for costly remediation.
A path forward
All the real-life findings prompted Kok and his fellow researchers to perform a comparison of traditional construction materials with composite matting solutions, focusing on their respective carbon footprints.
Given the reduced time on site, decreased heavy machinery operation time, and minimised remediation needs, it stood to reason that composite matting would have a lower carbon intensity.
To understand if composite mats present greenhouse gas savings over the conventional soil method, preliminary carbon footprint modelling was completed using the assumptions of laying down an access track for a copper string project. Based on the National Construction Code, Green Building Council of Australia and the National Greenhouse Gas Reporting Scheme, the scope of the modelling focussed only on direct emissions, indirect emissions, and embodied carbon.
“While the study is not a cradle-to-gate product carbon footprint, indicative results were promising – for an access track of 1km, using composite mats presented a 5 per cent reduction in total carbon emissions,” Kok said.
The findings of the research paper by Griffith University and independent greenhouse gas studies demonstrate that composite mats are well-positioned to meet the challenges of modern infrastructure.
As the industry shifts towards greener, less carbon-intensive, and environmentally friendly solutions, composite mats are gaining significant traction.
By highlighting the high value for money and multifaceted benefits of innovative products such as composite mats, rigorous research can help shift perceptions, transforming the way they are viewed – from mere products to holistic solutions that offer a range of advantages to the industry.
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