THE construction company behind the Toowoomba Second Range Crossing has shared a video of a controlled blast near Mount Kynock.

Nexus TSRC took to Facebook to share the video.

"We've been digging our way through the rock on the eastern side of the New England Highway at Mount Kynoch," Nexus TSRC wrote on Facebook.

"Now we need to carry out some drilling and controlled blasts to help with the hard rock we can't break up with machinery."

On its website Nexus said controlled blasting was a safe and precise method for loosening hard rock which was used alongside conventional construction methods such as excavators and scrapers.

"The Toowoomba Second Range Crossing is being built using a cut to fill process, whereby earth is 'cut' or excavated and moved to then 'fill' a new area or embankment which is formed by adding materials from the cut," the company said.

"To excavate the cuts, a variety of methods may be used depending on the ground material and include excavators, scrapers and blasting.

"For hard or high-strength rock, controlled blasting may be required once all other excavation methods have been exhausted. The scale of the blasting depends on the daily progress of excavation earthworks and is subject to changing weather and site conditions."