Electrical cables used for fire-resistant cladding

A researcher from the University of Melbourne has found that the plastic insulation around electrical cables can be used to make an organic, non-combustible and lightweight cladding core.

The rapid spread of the 2017 Grenfell Tower fire was blamed on the cladding, which was a widely used, plastic-backed aluminium, and resulted in 72 people losing their lives. Following this tragedy, the University of Melbourne said building codes have tightened to reduce the use of plastic-backed cladding, causing higher cladding costs, and the building industry has been working to create a lightweight cladding material that does not catch fire.

Lightweight cladding is typically made from organic, carbon-based, composite materials like plastic which are combustible, while non-combustible materials like steel, ceramic tiles or concrete are heavier and more expensive to produce and install.

University of Melbourne Fire Engineering Group research leader Kate Nguyen found that the plastic insulation around electrical cables uses tiny ceramic particles that activate and chemically interact with each other, forming and spreading a heat-resistant network through the material.

In partnership with construction materials company Envirosip, who commissioned the research, Nguyen experimented with different ceramic particles at the university’s testing furnace, and helped formulate a material that could withstand heat of 750°C.

The lightweight, pale grey material feels like a compressed powder and contains tiny ceramic particles that appear as dark specks. At high temperatures these particles blend with the rest of the material, turning it a dark grey colour and rendering it non-combustible.

The lightweight cladding core material showing the tiny ceramic particles. Image credit: Sarah Fisher/University of Melbourne.

The material has been tested by an independent testing facility approved by the National Association of Testing Authorities, and has achieved Australian and International Standards on combustibility of construction materials, specifically AS1530.1:1994 (R2016) and ISO1182:2010.

Envirosip and the university will now work to commercialise the development, which has been carried out as part of the Australian Research Council’s Centre for Advanced Manufacturing of Prefabricated Housing.

“When you are doing research, not all ideas will be successful. To go from success to commercialisation is another big step, but we believe we have developed something special that will be significant for the industry,” Nguyen said.

The research was presented at the 2nd Edition Fire Safety and Cladding Summit in Sydney.

Top image credit: ©stock.adobe.com/au/Nomad_Soul