Each month, illustrator Leo Greenfield sketches and profiles an Adelaide character who makes this city tick. This month: Anna Bartel.
As we drive, walk or cycle around town we often forget what is beneath us, but Anna Bartel knows exactly what the city grid is constructed on, as she builds roads as a senior engineer for the state government.
“To get really technical: we are talking about pavements, and the granular materials that make up the layers and the surfaces of highways and roads,” Bartel says as we sit at a cafe near her place of work on Grenfell Street.
As we chat over the cafe’s granite table, Bartel looks to the table to describe the way she examines elements from the earth that are used in construction. The table is made of coloured components, much like a core sample drilled from the earth. The colour variations within the granite are flashes of different minerals and matter embedded within the rock.
“It’s hard to convey that you can get so excited about rocks, but people in my industry have a real passion for these materials.” And you can see why: rocks, or quarried aggregates, form the basis of our built environment.
Over Bartel’s career she has worked continually to gain knowledge of the engineering properties of these natural materials. “By understanding the qualities of the rock, you can predict the way they will perform in road surfaces.” Through this analysis, engineers like Bartel started to build the layers that make up our roads while also “ensuring the quality, longevity and safety for road users”.
Bartel considers the quality of aggregates for roads, just like an engineer in another field would consider the quality of steel before pressing ahead with the construction of a building. Explaining her role further, Bartel draws a diagram showing a cross-section of the road beneath us, mapping out the layers of the crushed rock, asphalt, bitumen and sand. It’s a hot mix that is carefully considered and engineered to be lasting and carry the weight of constant traffic.
“The most important component of road construction is that the surfaces are waterproof; enemy number one is water getting into pavements,” Bartel says. “Our favourite line is: drainage, drainage, drainage.”
Bartel is based in the CBD but fieldwork is essential and takes her to rural and remote parts of the state. Working outdoors is something that drew her to engineering. Bartel combined her career with adventure when she worked in the Diavik Diamond Mine, near Yellow Knife in Canada. The temperature was -20C when she arrived to work at the mine for a year. “You could see the Northern Lights on night-shift and I thought, ‘How on earth did I get here’?”
Leo Greenfield is a freelance illustrator