Application: Concrete scanning used for car park column starter bars

Formwork and starter bars on carpark extension

The challenge

Westfield Chermside, Queensland’s largest shopping centre, is currently undergoing a major redevelopment which includes the construction of a second level gallery mall and expansion of its car park.

The installation of starter bars for 1300 new car park columns into the existing concrete slab posed a significant challenge. The new columns being placed over the existing columns of the lower level, meant the existing closely spaced reinforcement bars and post-tensioning cables had to be avoided when drilling holes for the starter bars.

Our Hilti solution

The Hilti PS 1000 X-Scan ground penetration radar was used to locate and mark out the lower reinforcements, enabling the safe drilling of four or six 350 mm deep holes for each new column. The holes were diamond cored at 35 mm diameter and the reinforcement starter bars were then installed using Hilti HIT-RE 500 epoxy resin. HIT-RE 500 was chosen for its high strength and slow cure time making it the best option for gluing rebar into diamond cored holes.

Hilti engineers have been a constant partner to the developer and contractors on this project, providing technical advice as well as liaising with the project’s engineering consulting firm with regard to product specifications, performance and compliance.

Locating existing reinforcements with Hilti PS 1000 ground penetration radar

Concrete scanning with Hilti PS 1000 X-Scan ground penetration radar used to locate existing reinforcements.

Marking out where it’s safe to drill starter bar holes.

‘X’ markings indicate where it’s safe to drill the starter bar holes.

Formwork and starter bars glued with Hilti HIT-RE 500

Formwork and starter bars glued with Hilti HIT-RE 500.

New concrete columns in carpark

New concrete columns in the carpark.