Three bridges, Adelaide Hills

Synopsis:

The problem 

These works were carried out on concrete/steel road bridges located over pedestrian walkways and creek beds. We needed to protect members of the public, the environment and the concrete elements of the bridge from the overspray of blasting and painting works.

The solution 

Before commencing any work, containment was established to ensure all debris was captured. This was facilitated by erecting scaffolding, around which we built timber framework, and lining the sides and floor with heavy‑duty, geo‑textile fabric.

The result 

All work on the bridges was completed to the highest standards, on time and on budget, to the satisfaction of DIT and all stakeholders without any harm to the environment or members of the public.

Project details:

The project scope

Initially we were contracted to carry out abrasive blast cleaning to the three bridges, plus application of a three-part protective coating system.

During the course of the project it was identified that additional works were required on two of the bridges, including repairs to steel bridge beams and concrete repairs to the sides and underside of the bridge deck. Steel beam repairs encompassed welding steel plates to the existing beams whilst concrete remediation consisted of breaking out damaged concrete and applying a zinc rich primer to exposed reinforcement. 

Larger repairs were formed-up and filled with repair mortar whilst smaller crack repairs were injected with an epoxy binder/adhesive.

These works were carried out subsequent to the initial blast and prior to the final application of the coating system.

Environmental monitoring 

Due to the presence of lead on one of the bridges, monitoring was undertaken to ensure works did not impact the local environment.

This included recording baseline data before starting work, taking readings when blasting was undertaken and taking final readings when works were complete.  

Results show that the works did not adversely impact the environment.