Road cutting w/diamond saws

And the next question.

Several states, incl WY, are having the diamond cutting machines cutting slots about 2" apart, 12", long across the aformentioned cuts that span the lanes, Then they jackhammer out the material between, blow it clean, and fill with "somehting".

What is the purpose of this process?

thanks

On Tue, 15 Sep 2009 06:18:53 -0600, the infamous snipped-for-privacy@hotmail.com scrawled the following:

They're called "expansion joints". When concrete expands in the heat of the day, those give it some place to go. when it contracts in the cold, they open up a wee bit. If the surface was all one piece, the contraction would open up gaps so large that VW Bugs and Chebby Metros would go missing. Hmm, sounds like a plan...

-- "To compel a man to subsidize with his taxes the propagation of ideas which he disbelieves and abhors is sinful and tyrannical." -- Thomas Jefferson

=A0 =A0 =A0 -- Thomas Jefferson

And, when a heavy truck tire crosses the 'gap' and hits the next slab, over and over, millions of times, the slab tilts near-end down, far- end up, making the impact on the slab even greater, accelerating the process.

I84 near fishkill used to be great for getting a little air from slab- to-slab in a few spots.

Dave

Only times I've seen them cutting out the expansion joints was to fix craters already present, repair rebar or mesh or add rebar in for rusted out spots on bridges. They then poured concrete level with the rest and it was good to go for another few years or until they asphalted over the road surface. Common summer repair job out on I80 in the wilds of Nebraska. Miles and miles of single lane traffic and no exits...

Stan

They lay in steel dowels-(half the bar is covered with a thin metal sleeve) then fill with Hi-strength concrete--keeps the two slabs from moving vertically relative to one another(working) under a passing load..In other words a Shear joint, that still allows for expansion/contraction.