Rigid Pavament Buckles on Cimarron T'pike

[HeavyCivil]

http://www.newson6.com/story/15059775/heat-buckled-highway-blamed-for-pawnee-county-crash

I understand concrete will undergo some thermal expansion, but I didn't realize to this extent. Usually we're more worried about it shrinking.

I wonder if AE concrete is not used in the south since there's less need for freeze-thaw resistance, and if, say, 5-6% entrained air would have helped here.

 

[ACtrafficengr]

I'm not sure if air entrainment would have helped, but better joint sealing would. Incompressible material in the joint is often a contributing factor to these.

However, preventive maintenance isn't sexy and therefore one of the first items politicians cut from the budget. No one ever does a ribbon cutting ceremony on a crack sealing contract.

Maybe the tyranny of Murphy is the penalty for hubris. -

http://xkcd.com/319/

 

[Ron]

VTEIT...long, narrow strips of concrete (i.e., pavement) will buckle in some areas of the US when high temperatures are experienced over extended periods of time. This is one of those areas that has a sufficient winter/summer temperature differential to cause this sort of thing.

There are lots of variables involved, but generally, if the temperature at the time of placement of the concrete was relatively low (usually lower than 60F) and the summer temperatures can exceed 100F, this potential is there. It usually also happens after a few years of the joint sealants getting harder (losing compressibility) from exposure and/or impacted with debris so that the ability for joint movement in compression is greatly reduced.

 

[HeavyCivil]

Ron:

Isn't the idea to keep a ratio of 1.5:1 or less? It looks like they achieved that here - not too long or narrow. Still I understand the cause. I guess doweling across CJ's is out of the question on highway projects.

 

[hokie66]

Dowels are used at the transverse joints, but they don't stop buckling at the joints if there is enough force

 

[BAretired]

Even in our temperate climate in the Edmonton, Alberta region, I have seen breaking up of concrete pavement due to expansion in the sun. It seems to me that wider expansion joints would resolve the problem but that would require more joint sealant, and that costs money.

BA

 

[a2mfk]

That is a motorcyclists nightmare! He flew about 150 feet! Poor guy...

It was interesting that the slabs stayed intact and lifted each other off the ground, reminds me of ceramic tile "tenting" failures. The slabs must have been relatively thick and/or well-reinforced.

As hot as it gets in Florida, you think that would happen more often here. Although it seems the FDOT uses mostly flexible pavement. Have you ever seen this Ron?

I wonder if AC isn't right about the non-compressible joint filler, though with DOTs and expressways they usually are VERY strict about what is used. It would seem as often as those joints were spaced there would be enough room for thermal expansion.

 

[hokie66]

I think this pavement was unreinforced. Look at how it failed in bending midway between the joints.

It is likely quite an old pavement, so has had time for the joints to fill with debris as Ron suggested. Poor rideability of this type pavement means that it is not in favour today.

 

[Ron]

a2mfk....I think the key to our pavements in Florida not doing this is the differential between temperature at the time of placement and maximum service temperature. Ours is not that great. Some places in the midwest can approach 100F differential.