Stronger for longer | Kaha ake mō te wā roa ake
Ever wondered what goes into making a motorway tough enough to handle extreme weather and heavy loads? Well, one of the secret weapons is good old cement!
While rolling and compacting various layers of gravel (aggregate), we incorporate cement to really bind it all together before topping things off with asphalt. This super strong layer is called cement-treated basecourse, or CTB for short. CTB improves the strength of the pavement to support the big loads that come from all that motorway traffic.
Last month, the crew finished laying all the CTB on the northbound side of the motorway along the full length of this stage (Stage 1A) of the project. The team are now busy doing the same thing on the southbound side, north of Papakura Interchange.
Before the final asphalt can be laid however, there's more work to do yet. On the northbound side we're installing concrete safety barriers using a crab-like machine called an 'offset slipform paver', more commonly called a slip-form barrier machine. This work needs the motorway to be closed during it for safety reasons, meaning it can only be done at night. Later this month, the slip-form barrier crew will move over to the southbound side to the north of Papakura and build more barriers there.
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