Concrete is porous nature, and as such absorbs and accumulates PFAS into its internal crystalline matrix. Left untreated and unprotected, PFAS-impacted contaminated concrete acts as an ongoing reservoir of PFAS, which continues to leach into surface water and the subsurface during rainfall events. Testing undertaken on PFAS-impacted concrete has shown that PFAS can penetrate to significant depth (>10cm) into the concrete pavement, and potentially right through into the underlying soil and groundwater, whilst still diffusing back up to the surface during substantial rainfall events.

Ambiolock employs a specialised mechanism by which the crystalline structures formed within the treated concrete matrix, prevent or significantly reduce the ability for PFAS to mobilise both into, or out of, the treated material, effectively locking PFAS into the solid matrix. This is beneficial, as when compared to chemical sorbents because common changes in the environment are unlikely to impact Ambiolock effectiveness or allow the release of PFAS.

Ambiolock permits the safe and effective on-site reuse of PFAS-impacted concrete, building materials, and granular soils and gravels. This avoids significant costs associated with the cost of transport and off-site disposal of the materials, which may need to be transported significant distances (i.e. NT to VIC), to a facility capable of receiving the material. Costs can range from a few hundred dollars per tonne, towards a thousand dollars per tonne or more for moderately to highly impacted material requiring transport across significant distances. This is without taking into account the greenhouse impact!

Reusing the PFAS-impacted materials on-site not only avoids the disposal and transport costs, and consequential environmental impacts and risks, but it also reduces the cost of new structural materials to be created on-site. Using recycled concrete aggregate on-site can reduce the cost of new concrete by around $100-130 per cubic metre, and even more for remote sites.

Where there are moderate to large volumes of PFAS-impacted materials requiring treatment, and opportunities for on-site beneficial reuse of the materials, significant cost savings can be realized.

Why is a bench trial required?

Ambiolock bench trials are undertaken to ascertain two key items:

1. That the product is fit for purpose, wherein product design or matrix does not impact product strength, workability or lifespan, and
2. That PFAS immobilization has been optimised to ensure maximum PFAS immobilisation and minimize cost.

What is undertaken in the bench trial?

Initially, Material Characterisation, which involves the assessment of client materials with respects to particle size distribution, PFAS concentration and leachability. This information alongside client end use brief will inform Ambiolock testing applications and product mix design.

Materials characterisation is followed by the core bench testing activities wherein approximately 60 monoliths are created using the product specific Ambiolock mix design and variable dosing, typically 5 set points are used to for the application curve (if there are two variables to be tested as is often the case for a complicated matrix, this would effectively double the number of tests to assess impacts of Ambiolock on concrete properties in combination with the waste material itself). Monolith are tested in triplicate for compressive strength and permeability which is compared to values preselected by the Ambiolock team as "fit-for-purpose" hurdles. Hereafter all materials are submitted in triplicate for PFAS LEAF leaching tests at timepoints 2, 4, 7, 14 days – the leaf test is modified to maximise surface area to sample mass ratio. Longer LEAF test periods can be used if required by any given regulator.

The data collected allows the compilation of performance curves with high statistical confidence, these are then submitted to the client alongside an appropriate application rate and the associated cost, as justified by the scientific data.


How much is a bench trial likely to cost, and how long does it take?

Due to the large factorial and the time needed to assess leachability, bench trial reports are typically issued between 2-3 weeks from commencement date. In the case of single variable bench trials where only dosing is being tested, trials typically range between A$15,000 to A$25,000, depending on the range of materials being tested, and number of applications proposed for the treated product. In situations where a complicated matrix results in the testing of 2 variables (dosing and matrix) testing may range from A$25,000 to A$35,000. These fees cover all works related to characterisation and Ambiolock application optimisation for your specific project.