jointing detail between existing and new pump paving

[Ariel Reyes]

Hello there,

Kindly provide some comments on the attached jointing detail between an existing and new 6" paving. As indicated on the plan and detail, the existing
curb will be demolished to enable extension of the concrete pavement which will serve as containment for additional valves and fittings w/c may leak
during maintenance.

Regards,
Ariel

 

[Ron]

This approach will not provide adequate load transfer across the joint. It's difficult to measure and assure you'll get the roughness you specified and using hardened to wet concrete epoxy is tricky, so a more straightforward approach would be better.

Provide hardened dowels drilled into the old concrete at 300mm spacing. Use 20mm +/- smooth dowels that are 450mm long. Drill the dowel holes 2mm larger than the dowel diameter. On the hardened side, glue a piece of foam on the end of the dowel before inserting it into the hole. Foam should be full diameter and 12-15mm thick. This is to allow expansion and movement of the dowel as the concrete expands and contracts. Grease the half of the dowel that goes into the hardened concrete, but don't grease the other half.

Now glue a piece of extruded polystyrene block that is 25mm x 13mm with the 25mm dimension in the vertical direction. Make the top of the block flush with the top of the hardened concrete. This will create a void when the concrete is placed and hardened that will allow you to put a proper sealant in place with a backer rod.

Place the new concrete using a concrete mix with the largest coarse aggregate you can reasonably get. This will reduce shrinkage.

When cured, remove the polystyrene block, install backer rod and use a sealant capable of withstanding traffic.

 

[Ariel Reyes]

Hi Ron,

Apologies for the late reply and many thanks. However, I've got a question to that approach. For a small paved area containing pumps with no likelihood vehicular traffic, is the use of dowels still applicable?

Regards,

Ariel

 

[Ron]

Yes, though they don't have to be as robust