Proof Rolling.....What? When? and How much?
Proof Rolling.....What? When? and How much?
(OP)
As part of the new city codes the city is requiring proof roll test on all new streets that are to be later dedicated to the city by the developer. On top of our normal QC/QA testing produceres. My question is what are some of the acceptable practices.
1) At what distance from the road surface should you be able to see movement? And is any movement allowable?
(We usually use a binder 19.5 mm asphalt mix then come back later into the development after construction loads have settled to lay a surface mix.)
2) Does a little movement (by little I mean you need to be on your knees and have the truck pull up and back up in order to notice it) in the sub-base material (limestone) matter in the long run?
3) Does movement automatically mean sub-grade failure? How can you tell if the problem is in the sub-grade pumping or just not enough compaction in the sub-base granular material? I understand the large movement pretty much means sub-grade, I am wondering more on the specifics of small non-yeilding movements.
Thanks for the advise!!
1) At what distance from the road surface should you be able to see movement? And is any movement allowable?
(We usually use a binder 19.5 mm asphalt mix then come back later into the development after construction loads have settled to lay a surface mix.)
2) Does a little movement (by little I mean you need to be on your knees and have the truck pull up and back up in order to notice it) in the sub-base material (limestone) matter in the long run?
3) Does movement automatically mean sub-grade failure? How can you tell if the problem is in the sub-grade pumping or just not enough compaction in the sub-base granular material? I understand the large movement pretty much means sub-grade, I am wondering more on the specifics of small non-yeilding movements.
Thanks for the advise!!





RE: Proof Rolling.....What? When? and How much?
Distance out to movement varies with the soil strata.
RE: Proof Rolling.....What? When? and How much?
2) "little" movement may not be a big deal depending on what it is due to. "in the long run", a pavement's performance is dependent on many factors beyond whether it holds up one or two passes with a LTADT
3) in some soils, a LTADT on the subgrade may cause surficial failure because it's so crappy as subgrade material...even if it is well compacted...but that same soil does "ok" if base course aggregate can be placed on the undisturbed material. pumping usually means not good subgrade soils...if the base course aggregate needs additional compaction, it will usually leave small ruts with no pumping.
proofrolls are subjective and almost always variable due to the different soil conditions that can exist. proofrolls are also difficult to fully explain...especially when considering all the factors at play to make a long lasting pavement section. have a trained geotechnical (or other qualified) engineer show you good, bad, ugly, perfect, etc...then have them explain how each of these situations can change dramatically based purely on the people involved in the project and everyone's expectations. i suggest that you always stay of the side of caution because a mistake or unidentified problem costs lots of money to fix. where ever possible, perform testing to design the pavement and to check in-place field conditions.
check the state DOT websites since they quite often have manuals on pavements. good luck.
RE: Proof Rolling.....What? When? and How much?
On the matter of rutting, pumping, weaving, etc. judgement is required, but none is great!
f-d
¡papá gordo ain't no madre flaca!
RE: Proof Rolling.....What? When? and How much?
We aren't proof rolling the binder. I just stated that because that is what will being going over the sub-base material and then we will wait for the constrution traffic to settle before applying the surface. We proof rolled the sub-base material and the city inspector noticed some movement and so now the contractor has to fixed the problem. I am wondering at what point do you decide to "fail" a proof roll. The area that was failed was about 3' by 6' and movement, if i had to put a number on it, was about a quarter to one half inch in the vertical direction and spread out maybe a foot. (not sure if thats how you measure or not)
Sorry about the confusion
Thanks!
RE: Proof Rolling.....What? When? and How much?
RE: Proof Rolling.....What? When? and How much?
Yeah, I guess it may not make sense why I said that - sorry. We were working a project where the binder was used to support construction traffic. I mean the binder got really messed up from all the LULLs and construction staging. So the owner had the entire binder proofrolled and in the process, cracked up the entire parking area. The original damage (i.e., from construction) too place in the winter and the proofrolling also took place when the binder/base aggretate was completly saturated. It was a huge mess!
I'd use the back wheel of a water truck. But, I'm always looking for trouble. . .
f-d
¡papá gordo ain't no madre flaca!
RE: Proof Rolling.....What? When? and How much?
RE: Proof Rolling.....What? When? and How much?
RE: Proof Rolling.....What? When? and How much?
f-d
¡papá gordo ain't no madre flaca!
RE: Proof Rolling.....What? When? and How much?
Thanks!
RE: Proof Rolling.....What? When? and How much?
RE: Proof Rolling.....What? When? and How much?
and yes, whatever goes back in needs to be placed in thin lifts and thoroughly compacted (my idea of thoroughly is certainly different than contractor's idea of the word). consult with a geotech if the contractor isn't paying to fix the area. if they're fixing it at their expense/headache, i'd consider not getting a geotech until the next time it fails proofroll.
RE: Proof Rolling.....What? When? and How much?
Thanks