Pavement design using roller-compacted concrete
Pavement design using roller-compacted concrete
(OP)
O.K. for starters, I know nothing about RCC (roller-compacted concrete). What I know is they use it for gravity dams, it has about a zero slump, and it's compacted using a roller (duh). I'm assuming that it's batched on site, as a concrete delivery truck needs some slump to mix and chute from the back side of the truck. Then again. . .
Here's a few of my questions: If you design an 8-in thick industrial pavement using 4-in slump, 4,000 psi, 6 percent air content concrete, how would you design an alternate for RCC? How do you get air content into the RCC?
Of what possible benefit would you get from a program such as this:
h ttp://www. cement.org /bookstore /profile.a sp?id=2309
Thanks in advance for any/all assistance. We have a client that wants us to specify RCC for his developemnt and we are talking about a 1,100 cy pavement job. I think the scale of the job sounds too small for this design change. Then again. . .
f-d
Here's a few of my questions: If you design an 8-in thick industrial pavement using 4-in slump, 4,000 psi, 6 percent air content concrete, how would you design an alternate for RCC? How do you get air content into the RCC?
Of what possible benefit would you get from a program such as this:
h
Thanks in advance for any/all assistance. We have a client that wants us to specify RCC for his developemnt and we are talking about a 1,100 cy pavement job. I think the scale of the job sounds too small for this design change. Then again. . .
f-d
¡papá gordo ain't no madre flaca!





RE: Pavement design using roller-compacted concrete
RCC can be batched on-site or done at a central plant and delivered to the site. It is generally handled as you would handle borrow material on an earthwork project and not unlike the process for soil cement. Dump trucks for delivery, graders and dozers to spread it, smooth vibratory rollers to compact. Place in 12-inch lifts and compact to the final thickness. No finishing, just 7 day cure like any other concrete.
My question is how will you get a smooth riding surface? RCC and soil cement are usually done for the base course with a riding course placed on top.
RE: Pavement design using roller-compacted concrete
RCC is usually batched at the site or you might be able to convince a ready mix supplier to batch it at a nearby plant; however, with essentially no slump and no latent water, you can't have a long travel distance.
Otherwise, I agree with cvg's comments.
RE: Pavement design using roller-compacted concrete
Dick
RE: Pavement design using roller-compacted concrete
I also don't know anything about RCC but expect with the use of a grader you would get similar tolerances to CSM which is roadbase tolerance rather than concrete slab.
I think its the wrong spec for the job and PQ Concrete would be a better option.
RE: Pavement design using roller-compacted concrete
I had never thought of finding a local batch plant and having the zero-slump RCC delivered in a dump truck. Believe it or not, that may actually work as I have a supplier close by the job.
cvg mentioned 12-in thick lifts. I like the sound of that, but it seems thick for an industrial pavement. Is 8 in an option for placing RCC (i.e., is 12 typical minimum)?
How do you manage air content? Is it a moot point owing to the fact that even with compaction, you'll end up with an air content that'll ultimatly work for freeze-thaw conditions?
Thank you all so much for your help!
¡papá gordo ain't no madre flaca!
RE: Pavement design using roller-compacted concrete
Regarding timing for transporting and placing the mixture, these are specs from my most recent project:
A. The CONTRACTOR shall minimize the total elapsed time between the addition of water to the mixture and the completion of compaction. Time limits for handling, transportation, and compaction of the RCC shall be as follows:
a. Maximum transportation time from mixing to the start of spreading shall be 30 minutes.
b. Compaction shall start within 15 minutes of spreading.
c. Maximum elapsed time between introduction of water to the mix to final compaction shall be 60 minutes.
RE: Pavement design using roller-compacted concrete
This is an opportunity to work with/for your client so he can use the project as a demonstration project and you can document the use and application for a non-mass installation. If the client is one of the large international cement producers that have more knowledge and technical support than an ordinary concrete engineer.
The specs you posted require nothing more than a stop-watch to insure quality, which is minimal.
Do not worry about air content since that is in realm of cast concrete and not zero-slump concrete. The vibration and compaction will change the air content of the placed concrete plus there is no guarantee that the air is too much more than the normal 1.5% generally in any concrete.
When you are dealing with zero-slump or very low slump concrete, the shape of the aggregate (rounded, spherical, etc., has is a very big factor in the performance. It is not that much different than the soil proctor tests commonly run using the locally available aggregates. It is good to have a supplier that is experienced with RCC concrete, but that could be controlled by your client, since concrete suppliers have their prime cement suppliers and cement producers also have their prime customers/producers. The best of both worlds would be a concrete supplier that is vertically integrated to the cement/aggregate supplier from a standpoint of technical assistance and future projects.
Dick
RE: Pavement design using roller-compacted concrete
One item of note: We are somewhat concerned about how to handle contraction joints in RCC installation. Recognizing that all concrete cracks (and that RCC is concrete), and recognizing that the service load will be fully-loaded highway trucks that are moving portland cement cracks that loose aggregate interlock may lead to premature failure. In a slump concrete, we can use dowel baskets at the control joints as a backstop to aggregate interlock. In RCC I guess this is not an option. That said, I'm suspecting that RCC is less susceptable to slab curl and the like.
I really appreciate everybody's comments. My client has good relations with the Portland Cement Association and is working with their engineers to look at RCC design for the anticipated loading and site-specific CBR values. I'll give you all an update.
Have a great weekend!
f-d
¡papá gordo ain't no madre flaca!
RE: Pavement design using roller-compacted concrete
RE: Pavement design using roller-compacted concrete
Having had a think about this and compared to the use of CSM (cement stabilised material) I would investigate using a paver (i.e the type used with bitumenous road surfacing). I think a good level control could be achieved and the augers tend to lay the material evenly prior to compaction. The semi-dry (or dry??) concrete could then be supplied by a pugmill at site, into trucks and then reversed up to the paver.
RE: Pavement design using roller-compacted concrete
If the cement producer is really controlling things, they may have their mind on a certain type of application and want it done correctly, since it is critical for them to do it right.
Although concrete pavers use less cement they have been used successfully in international projects with heavy loads on marginal soils (heavy duty straddle loaders in ocean ports handling multiple containers or for airport taxiways). This could also be an attractive alternate, depending on the clients engineering/promotional interest.
If not, just rely on the technical support offered by the client and learn something with a different application. - you know this is not a project that the budget is not as important as the performance and educational/promotional value.
Dick
RE: Pavement design using roller-compacted concrete
Any chance when the project goes to construction you could give us a heads up? I believe you and I are in the same vicinity, and if the project is nearby I would like to see the RCC placement process if possible.
Dan
RE: Pavement design using roller-compacted concrete
RE: Pavement design using roller-compacted concrete
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: Pavement design using roller-compacted concrete
Diamond Ground RCC Replaces Failed Asphalt on US Highway 78
U.S. Highway 78 in Aiken, S.C., had deteriorated to the point where a thin resurface treatment was not a viable option. Looking for a solution to replace the failed asphalt roadway, the South Carolina Department of Transportation (SCDOT) explored multiple options, primarily focusing on minimizing traffic disruption, long-term durability, and cost of construction. The repair method chosen consisted of milling out the distressed asphalt and replacing it with 10 inches of roller-compacted concrete (RCC). To provide the desired ride quality for high speed traffic SCDOT chose to diamond grind the RCC surface rather than cover it with a thin asphalt or conventional concrete surface.
When it was successfully completed in August 2009, the diamond ground RCC pavement paved the way to add high-speed roads to the list of RCC pavement applications. For typical roads with speed limits of 45 mph or higher, a smooth road has an International Roughness Index (IRI) of 85 inches per mile or less. Approximately one week after placement, a milling machine was used to remove higher surface spots of RCC. This was followed by diamond grinding to provide the final smooth surface. After grinding, the pavement IRI was determined to be within the range of 50 to 60 inches per mile.
This project marks the first successful completion of diamond grinding RCC pavement for a major road in United States.
RE: Pavement design using roller-compacted concrete
Thanks! I'll forward this to my colleagues and client. This project is moving forward and I'll followup when I have anything.
f-d
¡papá gordo ain't no madre flaca!
RE: Pavement design using roller-compacted concrete
Even though you are rolling the concrete and getting full compaction, you will still have air entrapped withing the paste. Don't think of it in terms of "air voids." Now I am no Dam Engineer by far, but I know concrete very well. It's probablly safer to batch a mix with minimum entrapped air. All entrapped air content is really good for is workability. I personally hate entrained air in any mix. However, you can't get rid of it even if you exclude air admixtures out of the mix design. It naturally is incorporated by the mixing action. PCA makes an excellent book on this. It's really an essential book if you are into concrete structures PERIOD. Every engineer needs to read it. Good Luck!
RE: Pavement design using roller-compacted concrete
f-d
¡papá gordo ain't no madre flaca!
RE: Pavement design using roller-compacted concrete
Thnx
RE: Pavement design using roller-compacted concrete
RE: Pavement design using roller-compacted concrete
Be nice to me, as I'm really not that familiar with RCC, but do understand nobody wants a road that busts all up after the first really cold winter - ha.
f-d
¡papá gordo ain't no madre flaca!
RE: Pavement design using roller-compacted concrete
There are a few manufacture's who produce good quality liquid admixtures....
Darex is a brand I'm more familiar with.
Masterbuilders INC.
Boral INC.
Anyways, yes air admixtures are quite common!
RE: Pavement design using roller-compacted concrete
f-d
¡papá gordo ain't no madre flaca!
RE: Pavement design using roller-compacted concrete
Digger
RE: Pavement design using roller-compacted concrete
f-d
¡papá gordo ain't no madre flaca!
RE: Pavement design using roller-compacted concrete
RE: Pavement design using roller-compacted concrete
Would that the type of aggregates, percentage of fines, level of compaction have something to do with its duribility?
RE: Pavement design using roller-compacted concrete
RE: Pavement design using roller-compacted concrete
You shall be able to answer my question in general sense. Appreciate your comments.
RE: Pavement design using roller-compacted concrete
RE: Pavement design using roller-compacted concrete
RE: Pavement design using roller-compacted concrete
1. China Experience (DAM - Freeze & Thorw Resistance Study):
http://ww
2. PCA Article (RCC Pavements):
http://www.cement.org/pavements/pv_rcc.asp
3. Abstract from University of Wisconsin Milwaukee (PDF)
RE: Pavement design using roller-compacted concrete
RE: Pavement design using roller-compacted concrete
RE: Pavement design using roller-compacted concrete
RE: Pavement design using roller-compacted concrete
RE: Pavement design using roller-compacted concrete
RE: Pavement design using roller-compacted concrete
RE: Pavement design using roller-compacted concrete
RE: Pavement design using roller-compacted concrete
Newly rebuilt Missouri dam uses roller-compacted concrete
A rebuild of Missouri's Taum Sauk Upper Reservoir dam -- following a disastrous over-topping in 2005 that sent a 20-foot wave down the mountain on which it is built -- is almost finished, and the newly reinforced earth-and-rockfill dike should be ready by April 1. The new dam uses roller-compacted concrete that was made by pulverizing rocks from the old dam. Engineering News-Record (1/27)
http://enr