2015-03-31 I&S Committee - Item 5 - Attachment 1 - Munna Pt Bridge Repairs Level 3 Bridge Report

        §   Carbonation had not penetrated far into the pilecap concrete, except at TMR
             Core 7 on Pier 5, where the concrete had cracked.
        §   Alkali Silica reaction (ASR) was found in the pilecap concrete, by petrographic
             analysis.
             Notes: The TMR analyst noted the potential for ASR was “very mild” and
             described the actual ASR reaction as “mild”. The concrete was made with
             unblended [Portland] cement. Modern concrete in Queensland is batched with
             a blend of Portland cement and flyash (pozzolanic cement) to prevent ASR
             problems.
        §   Concrete compressive strength can be taken as 39 MPa, from testing of TMR
             Core 13.

o   Piles
        §   5 of the 6 piles that were inspected by divers had vertical cracks on all faces.
             Notes: Pile 1 (Pier 1), Pile 10 (Pier 2), Pile 2 (Pier 3), Pile 2 (Pier 4) and Pile 5
             (Pier 5) were cracked. Pile 10 (Pier 6) was not.
        §   TMR advised that alkali silica reaction (ASR) must be present in the piles.
                Notes: TMR comments were based on the crack width, orientation and
                consistent appearance with TMR piles with similar ASR problems. No lab
                testing of piles for ASR was carried out.

o   Repair actions
       § None taken

2004: NSC arranged for a visual inspection and diving inspection

o   Pilecap Beams
        § Cracks in the pilecap beams had worsened

o   Piles
        §   Pile 1 (Pier 2) and Pile 3 (Pier 2) had cracks that a ruler could be pushed into.

o   TMR recommendations
      § Repair cracks/delaminations in pilecaps [beams]
      § Control corrosion of steel in pilecaps [beams] by cathodic protection
      § Confine piles with encasement

o   Repair actions
       § None taken

2009-2010: OPUS prepared bridge condition reports for the SCC

o   Deck units
       § Chlorides were just below the corrosion threshold value for the tested deck
          units
          (Deck unit 2 and 4 were tested, adjacent to Pier 3)
       § Carbonation had not penetrated far (5-15mm) into the deck units

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