Question for Highway/Civil Engineers out there!!

[usbusin]

In my travels in recent years I have noticed a method for smoothing out the "truck lanes" on concrete highways.  It appears that the expansion joints are somehow tied together to remove the horrible undulations set-up by heavy truck traffic on concrete highways.

What I see is:     l l l      l l l

                        l l l      l l l

                        l l l      l l l

                        l l l      l l l

What are these and what is the process for taking out the undulations?

Curious minds would like to know!

[boogiethecat]

They cut these notches at the junction of two slabs, toss in big thick hunks of something similar to rebar and then fill it back in with cement...at least that's my observation...
Then at least around here they grind the entire highway flat. It makes it all REALLY smooth to drive on!
Still, I frequently see the notches loosing their cement to form a messy hole... guess sometimes it just doesn't work right...

[Iceni John]

Some of I-405's lanes in Orange County CA had this done a few years ago, but since then their surface has begun to deteriorate again.   I don't know if this is an accepted remediation method or just a short-term expediency, especially considering  California's present fiscal woes.

[robertglines1]

I ran milling machines on highways and runways if the marks you are referring to or on surface they are leveling (milling) if on new construction (baskets) rods between expansion joints are designed to let the Slab sections room to expand and contract the rods are usually about 1 1/2 inches dia and 2 ft long about 12inches apart...if repair they drill into good concrete and extend into fresh Slab to act as a reinforcement/expansion joint...If put in to shallow they could be breaking Thur surface..I hope this helps and will be what your talking about..I also ran the slip form (concrete pavers) also..we injected pins in side of slab also to form joint with ajoining lane when poured...Bob

[Eagle Andy]

Wow They are doing that right now on I 94 in Glendive mt inconjunction with some bridge work I wondered what the heck they were doing . Thanks

[rusty]

The old norm for concrete paving was to pour the slab and cut control joints every 15 feet or so without dowels to tie the slabs together. Over time with movment and freeze thaw the slabs will move and you end up with an uneven road. What you see is them adding the dowels to help the slabs to move together. The new paving method is to add the dowels as they are paving and saw the control joints over where the dowels are.

Wayne

[usbusin]

Thanks for all the interesting info on highway construction.  I knew I could find the answer on this board with the diverse backgrounds around here!  And, yes, it sure smooths out the roadbed!

Thanks again.