What is Polyrok?

Polyrok concrete is the latest innovation from Replas, a sustainable recycled plastic aggregate alternative to mineral aggregate in concrete for pathways, kerbs & channels that find a home for the most problematic waste stream, soft plastic. Polyrok consists of about 95% Red Group post-consumer soft plastic waste with about 5% engineered recycled content to ensure maximum performance in concrete. State of the art technology allows Replas to use soft plastics that are recovered from the REDcycle program in Coles and Woolworths with leading packaging brands. Fit for purpose, strong, and durable recyclable concrete from Replas is the new way for councils to be part of the Circular Economy.

This latest innovation from Replas results in a superior product that has benefits over conventional concrete. Specific plastic-to-cement binding technology has been tested to meet Australian Standards, efficiently and effectively replacing conventional mineral aggregate while diverting plastic from landfill. We are challenging every Council in the country to get on board to be part of the solution for their plastic waste.

If each Council in Australia committed to just one kilometre of footpath, 1,900 tonnes of Polyrok (approx. 470 million pieces of soft plastic material) would permanently become part of the communities’ walkways. 

Polyrok Products

Polyrok Civil

Suitable for footpaths, curbing & more

Concrete Your Future With Polyrok

The Sustainable Aggregate Alternative from Replas 

Frequently Asked Questions

20 tonnes of Polyrok are produced per week, with over 20 tonne currently in stock (April 2021)
Made from Polyolefin plastic, Polyrok has no chemical reaction with other materials or admixes. Silica fume has shown excellent interactions with Polyrok. Silica fume is an extremely fine material and helps the cement paste flow into the surface voids of Polyrok. This type of plastic is extremely stable and inert with a well-known and accepted safety profile, handling it and incorporation into concrete will not create any emissions and requires no additional PPE.
No, the concrete would need to be severely over vibrated to do this.
Lab and field-testing using table and needle vibration have not shown this to be an issue. Polyrok has an SG of 0.85 which is not low enough to stimulate buoyancy in the thick concrete mixture. Over 100 Xray CT scans of cylinder test samples, compacted by table vibration, have shown Polyrok remains evenly distributed (even in percentages above 20%).
Yes, a 10% volume of Polyrok blend delivers a 4% reduction in thermal mass.
Polyolefins in particular are so stable they are used to package the most aggressive chemicals (acids, solvents) and trusted to package the most sensitive of products such as food and pharmaceuticals. Polyolefins would need to be heated above their process temperature of 200C to begin thermally degrading.
Polyrok flows well in pumping equipment with no issues. The aggregate size is 4-8 mm and is lighter than natural, conventional aggregate, making it pump more easily.
Polyrok is a coarse aggregate and is totally encapsulated in the cement/sand in standard finished concrete. This means the Polyrok is never exposed to the external environment. Accelerated wear testing, completed by RMIT University, has shown concrete containing just 5% Polyrok has a 11.5% higher abrasion resistance compared to standard concrete.
Recovery of Polyrok from concrete crushing plants is a simple process using an air knife system (standard in most systems) or a zigzag air separator. This process has been a standard requirement for many years due to other plastic components in concrete such as bar chairs, poly film and mould inserts. Polyrok can then be reused as aggregate or for other purposes. Please see video: https://www.youtube.com/watch?v=z1mPeAoXLzk

Get in touch to make your Council next in line – find out how to concrete your future with Polyrok.

Goal: 500 Tonnes By End Of 2021



: Plastic predominately sourced from post-consumer waste

Main Polymer Constituents

: HDPE, LDPE, there may be traces of CoPP

Polymer Thermal Conductivity Range

: 0.35 to 0.5 Wm-1K-1

Polymer Specific Heat Range

: 1700 to 1900 JK-1Kg-1

Polyrok Geometry

: Specifically tailored to replicate natural aggregate

Target Aggregate size

: 4-6 mm


: 0.4 – 0.5 kg/L

Environmentally Friendly

Replas’ plastic recycling leads to low maintenance products that are designed to last. Recycled plastic is resistant to termites, microorganisms and moisture, and will never split, rot, crack or need painting. Through the REDcycle Program Replas is proud to partner with companies, such as Coles and Woolworths, who have taken responsibility for the plastic waste they create. The soft plastic material collected through the program can be recycled by Replas and turned into products designed for outdoor use within the community.

Replas Environmental Statement

With plastic use on the rise, we need to create a sustainable community that reduces, re-uses and recycles plastics. At Replas, we see waste as a valuable resource, and are part of making this world more sustainable. What is the environmental cost in not being involved in the circular economy? By re-thinking your selection and procurement to recycled plastic products, you become the true recycler. Everyone touches plastic and we must be more accountable and responsible if we are to drive demand for recycled plastic products.