CRC has repairs that are over twenty years old which haven’t moved; however, we also have warranty work. Consider the slabs we work on. There are panels that took over fifty years to move and others that aren’t even a year old.  These disparities are sometimes easy to explain such as a pipe failure or a tree next to a slab. But, the true reason is usually a bunch of little factors that lead to the problem.

I like to say past performance is usually indicative of future performance.  If a slab took five years to fail, then odds are our repair will start to move in about five years.  Now some will say this is a failure, but if you instead went with tear out and replacement the odds would still say that the new slab will move in about five years. The truth is you are where you are, and the soils in that particular area are going to do what they want to do.  Of course, there are usually ways to engineer around most of these issues, but for residential or commercial projects the cost is usually prohibitive.

So, where does that leave us. We have repairs that are long term fixes, and we have others that are just managing issues (soils, trees, drainage, etc).  Looking at the problem from a cost perspective you should try to extend the length between tear out and replacement as long as possible. Imagine a leaky roof. Sometimes you just need to patch the leak and other times you need a new roof. That is where our repair fits in. Our method of repair extends the useful life of your concrete, but the time between repairs is dependent on the soils underneath.  After all we are just along for the ride.

This job could have been repaired with cementitious grout (mud jacking) or polyurethane foam.  The client in this case went with polyurethane, due to the smaller injection holes.  If we went with mud jacking, then we would have needed to core the holes adding time and expense.  If aesthetics weren’t a concern, then mud jacking would have been the cheapest option.  Luckily, with CRC you have options and the know how.

Just wanted to show off our recent wrap of our foam lifting rig.  It’s now decked out in the Red, White and Blue.

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SPALLING

While the world isn’t ending, this concrete is moving.  A void has developed under the slab, which in turn has allowed the slab to flex as traffic goes by.  There are many factors that can cause the initial void, but at this point water will expand the damage.  Water gets under the slab and fills the void, then traffic travels across pushing out the water.  This water contains some of the base material, which means the void increases in size as each vehicle passes.  This damage spreads out, slowly destroying the pavement as it goes.

Our process can stop the spread by a process we call stitch grouting.  We drill holes on either side of the joint and pump our cementitious grout to displace any water and replace the lost base.  There could be some additional steps depending on usage, but that’s about it.  Sometimes you can even avoid the spalling if you are very observant.  If you are walking on a street or drive and notice a lot of sand(especially at the joints), then it’s possible this process could be in the beginning stages.

We are often asked about slabs that are severely broken – “Can I repair this with mud jacking or is it time for tear out and replacement?”.  The answer really is “It depends”.  Specifically, it depends on your expectations and our experience.  Have a look at the pictures below.

My recommendation to this homeowner’s association was the drive needs tear out and replacement.  The manhole most likely has some issues which are causing settlement along the centerline of the drive (over six inches of drop at its worse).  In addition, the concrete has cracked up.

Of course, from the pictures you can tell there isn’t any new concrete.   The association’s budget couldn’t handle the price tag of tear out and replacement, so we came in and did the best we could.  It is also safe to say that our material sealed up some of the manhole issues.  After many years this area has moved around a little, but it is still usable and has yet to be replaced.  This additional time has given the association flexibility with their budget and in this case the cost vs. time gained was definitely worth it.  So, as I said in the beginning – It depends.