12 Creek Street, External Wall Condition Assessment

A commercial building at 12 Creek Street in Brisbane's CBD required an independent condition assessment of its external walls to inform the asset management strategy. Allied Commercial engaged TRSC to determine the actual condition of the concrete envelope and establish the appropriate scope of intervention based on measured engineering data.

TRSC structured the investigation as a Stage 1 Cover, Chloride and Carbonation Assessment combining non-destructive and destructive testing. Non-destructive investigation utilised Ground Penetrating Radar (GPR) for reinforcement location, Ferroscan for cover measurement surveys, and X-Ray Fluorescence Spectrometry (XRF) for material composition analysis. Destructive investigation included cored samples for laboratory chloride profiling at multiple depths and carbonation depth measurement using phenolphthalein indicator testing. Carbonation modelling was conducted to predict future penetration rates against the measured cover depths.

The investigation established that chloride concentrations across the building envelope were consistently below the corrosion initiation threshold (0.008–0.036%, well below the 0.06% threshold). Carbonation penetration of only 2–3mm was measured, minimal relative to the concrete cover depths present. Concrete cover measurements confirmed adequate protection to reinforcement. The investigation conclusively demonstrated that reinforcement was not at risk of corrosion, and that surface coating renewal rather than concrete remediation was the technically justified intervention.

TRSC's investigation confirmed that the building envelope was performing well within acceptable parameters for continued service. Measured chloride and carbonation data provided a clear evidence base for future maintenance planning. A targeted coating renewal programme was specified to protect the concrete envelope for a further design life cycle, an intervention scope proportionate to the measured condition.