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We received a question from an active construction project and they were hoping to get an answer today.  Their question has to do with the anchorage of a permanent concrete median barrier wall.

INDOT standards allow two options either anchor into an existing concrete pavement or counter sink the base of the median wall between two shoulders, a picture of the Current INDOT Standard Drawing is shown below. 

The project plans calls for:

• the existing median barrier wall to be removed to construct a crossover,


• the opening between the existing shoulders is to be filled with asphalt for maintenance of traffic (MOT), and


• when the MOT is complete, the asphalt is to be removed and the new median barrier replaced similar to the detailed for NEW PCC PAVEMENT, see below.


 

The contractor would rather:

• remove the existing median barrier wall to place the crossover,


• fill the opening between the existing shoulders with concrete, and


• once the MOT is complete, leave the concrete in place and anchor the new median barrier wall as drawn below, Contractor Proposed Anchorage. 


 

This proposal is a mixture of both the current INDOT anchor standards.  Can you offer any guidance as to way the contractor’s proposal will work or will not work? 

I just received some additional news, the contractor plans to place two anchors side by side on 12 in centers, see below.  We believe this proposal would allow the median barrier to work as a monolithic section and better represent the NEW PCC PAVEMENT detail shown in the original email below.

I believe the proposed anchorage method would work nearly identical to your “NEW PCC PAVEMENT” anchorage.  The only question I had – Is the depth of the concrete slab that will be placed in the median the same depth as specified for new pavements, and how does it compare with the existing shoulder thickness?  If these are all the same, and the dowel rod length and embedment are the same, the proposaed design should provide the same anchorage as the your new construction standards.

Existing mainline & shoulders consists of 12in concrete pavement.  The proposed median depth would match the depth of existing pavement matching the ‘new pcc pavement’ barrier cross section detail (with the exception of the construction joint)