Tonnes of artificial plasticine made from concrete and fly-ash are being pumped under the Ipswich Motorway near Redbank Plaza to stabilise old mines underneath the $3 billion road project.

Already, 7000 cubic metres have been pumped beneath the motorway, with more to be added over the next 12 months.

The site in Redbank where authorities are filling old mine shafts beneath the Ipswich Motorway.

The Queensland Government has also commissioned the CSIRO to spend $2.3 million to see if it is feasible to use the same technique under the nearby homes at Collingwood Park affected by mine collapses.

Member for Bundamba Jo-Ann Miller said fly-ash - a waste product from burning coal - from the nearby Swanbank Power Station was now being mixed with cement and crusher dust and packed into the mines.