Recommendations for Track Curing Time

[Rhonda Mims-Brown]

For those with track construction experience, what's your recommendation for track curing time on a newly poured asphalt circuit. For that matter, what also would you feel are ideal conditions to pour. What would be most detrimental in your opinion?

Thanks!

[michael coello]

quote:

---

Originally posted by Rhonda Mims-Brown:
For those with track construction experience, what's your recommendation for track curing time on a newly poured asphalt circuit. For that matter, what also would you feel are ideal conditions to pour. What would be most detrimental in your opinion?

Thanks!

---

Hello!

First of all asphalt is laid and concrete is poured.
Asphalt starts out extemely hot thus giving the product workability. It hardens as it cools. The cooler it gets and the faster it can over an extended period of time the better the strength. The tighter the compaction the better the strength.
With that said the problem with karting applications is the size of the compaction roller needed to get adequate compaction but still be able to get around the tight radius's needed for a karting layout. For example the larger the roller the better the compaction. However, as it goes around the corner the roller/drum starts to slide and tug on the previously placed asphalt. the more tugging or pulling the more voids between the aggregate the less strength. The smaller the roller the easier it is to make the corners without tugging but it will not compact as tight directly below the compaction drum. Obviously it is the corners that are most important with the sticky tires and high g's that the karts pull today in regards to which way you should lean for proper compaction. Therefore, a good balance of compactor size and compaction needs to be addressed.
Anyway getting back to the best weather to do this in is one that allows for moderate setting while laying it down(50-60 degrees fahrenheit) and then getting colder over night for gaining strength. The time to let it cure depends on how cold it gets and for how long. If it gets too cold then frost heaving the track before it is strong enough becomes a factor also. Therefore 32 to 50 degrees for a couple of weeks should provide an adequate atmosphere for the asphalt to set well enough for club racing on a fairly moderate compound (ex. SL4, YHC, etc.) You will need more time than that to get the strength needed to sustain YEX rubber from 125's on a hot day.
The other important factor is if the asphalt is being put on a fresh nicely compacted base or on top of other asphalt. As the asphalt sets it gives off chemical gasses and moisture. If this moisture has no where to go but up(ex. in the case of going over an existing track) the chance of the bottom not setting idealy may be a problem to take into consideration. If I have not confused you enough just ask me about concrete. The medium I deal in every day. Hope the facility turns out as good as your planning. Good Luck!

Michael Coello

[Mike Weaver]

When we did Badger, we closed our track a little early in the season and had the entire track redone in Sept/Oct and let it cure over the winter. Then we opened a little later than normal in the spring to give it every last minute we could.

[Drew Cleaver]

PLEASE TELL ME YOU'RE BUILDING A NEW TRACK IN TEXAS!!!

We could use a track in the Houston area,
Drew Cleaver www.vmaxracing.cjb.net

[Jimmy Moore]

Are there different asphalt compounds? I hear there is an asphalt compound they use on the roads in Sweden that is far superior to what they use here in the USA. What's the best way to patch a torn up corner?

[Rhonda Mims-Brown]

Thanks to all for the input so far...I love these discussion forums! No, we are not getting a new Texas track (wish it were so).

I ask because of a new track in Colorado I am working with. They asked me what I thought and this is not my area of expertise. The new track is a brand new Road Course, Sprint Track and more! Hopefully, I can get the promoters to make an announcement about this wonderful facility soon!

Michael...as always, your input is priceless! Thanks for the lesson and for bringing up the difference between asphalt being laid and cement being poured and making me sound really stupid! If it's okay, can I have the owner e-mail you for any additional input?

[lynn haddock]

Another good trick for brand new asphalt that has worked well.....while the pores of the material are still very open, cover the corners with pure cement powder and broom it in.........then just wait til it rains. It tends to hold the asphalt together.

[michael coello]

If it's okay, can I have the owner e-mail you for any additional input? [/QB][/QUOTE]

That would be fine if the owner wants to email me or some other contact. Also Lynn's ideas as always are spot on with the cement powder being applied to the corners.

Michael Coello