Title: Repair of Concrete “In-Service” Rail Headstocks Port Kembla Rail Facility

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Publication: CIA

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Date: 2/28/2011

Abstract:
The bridge lies on the main rail access to the Bluescope Steelworks at Port Kembla & the remediation process involved the concrete repair and coating of two concrete capping beams whilst they continued to be in service with up to 30 irregular and at times unscheduled crossings per 24-hour period, with some trains carrying up to 63 tonnes per axle. The bridge pier concrete capping beams exhibited significant spalling of the concrete, with reinforcement exposed in many places and with the embedded reinforcement showing signs of corrosion in all exposed areas. Cardno Engineering, in conjunction with Fluor Global Services, called for a repair system that could be installed using a high early strength mortar, along with Cathodic protection systems, to combat high levels of chloride contamination within the concrete matrix. The proposed method of repair by the winning Contractor included demolition of the spalled concrete using high-pressure water blasting from the truck-mounted equipment & experienced operators. The equipment delivered 1,250 bar at the nozzle and was able to carefully and accurately remove concrete from around the corroded reinforcement with out “over break” and micro-cracking often associated with mechanical removal processes.