Asphalt Compaction
Asphalt Compaction
(OP)
I'm requesting my esteemed colleagues to provide me some details of compaction requirements for base asphalt and wearing course in your state, province, country. For example, some jurisdictions use 96% Marshall compaction of Marshall 75 blows. Others use 98% Marshall compaction at 75 blows. I am looking for national highways, major state highways (e.g., US40, US20, I-75). Added information if your specs call for it as to % air voids or % voids filled with aspahlt at primary compaction would be useful. I am looking mainly to dense graded mixes, not open graded. Thanks to all.





RE: Asphalt Compaction
RE: Asphalt Compaction
http://www.trans.gov.ab.ca/Content/doctype245/production/Specs2003.pdf
I hope this long thread works. Go to Section 3.50. The various mix types are a function of design ESALs. Oil grade selection is also a function of ESAL's as well as climatic conditions. Some guidance in selecting the mix type and oil type specific to the above reference might be found at the following link:
http://www.trans.gov.ab.ca/Content/doctype233/production/pavedm2.pdf
I hope this helps. Compaction for this jurisdiction is 97% Marshall with pentalties and bonuses applied to lower and higher field compaction. You will find all applicable mix parameter specs at the first link site. Superpave specs are also available.
RE: Asphalt Compaction
http://fhwapap04.fhwa.dot.gov/nhswp/index.jsp
This site consists of a searchable library of highway specifications from across the United States of America. The site also features Discussion Forums to enhance communication and interaction in the development and use of various types of construction specifications.
RE: Asphalt Compaction
RE: Asphalt Compaction
RE: Asphalt Compaction
95% - ASTM D-1559 - 75 blows
or
93% - ASTM D-2041 for Asphalt Int. SP-2 Gyratory method design
Reductions in payment for insufficient density if more than 1% low
RE: Asphalt Compaction
I do not like comparisons to Marshall results - what if Marshall SG is low and compaction is poor in field - you still would get a good value for %compaction versus a lower Marshall value, but would most likely be upwards of 9% to 11% airvoids (when compared to Rice values). A spec with percent compaction based on Marshall values should also be accompanied by specs for %VMA or %voids filled in order to ensure that a good mix is being placed. This can be a real problem when producer makes a fine and dry mix (the cheapest kind to make). Just my $0.02 worth - after working both sides of the fence (producer and tester).
RE: Asphalt Compaction
RE: Asphalt Compaction
Sounds like your client has the same specifier as one of our big box boys (the home improvement store that's not orange in color). Their spec says that contractor shall compact mix until 96% of Rice is achieved. If contractor does this, he/she has already killed all the voids that normally would consolidate over the pavement life cycle. Kind of hard not to expect some shoving, rutting, etc. if one tried to get 96% of Rice. As far as flushing of the binder, if such a high spec is required, specifier has to know that if you compact it so hard that binder 'leaks out', something has to be wrong. I'm sure you've already told him/her this, but the pavement can expect to become rutted very soon, particularly if any heavy truck loads are applied. Soon after the rutting, I'll bet it starts to slide and pop open, thus causing shrinkage cracks followed by the evil POTHOLE (run away!!!).
Although my call name is dirtdoctor, my first love is the hot black stuff. Scraping of fines at surface - sounds like contractor has fined up mix a tad or else the rubber tire roller is not hot enough to keep from picking up the fines in the mix.
The glory days of pavement will arrive in the US soon, as Stone Mastic (or Matrix) Asphalt will become a reality. The Europeans (particularly Germany) have been using it for years, with much success. After Georgia DOT bit the bullet and put it down on I-85 (perhaps the one stretch of pavement in the US to see the harshest conditions - heat, heavy truck loads, along with freeze-thaw cycles) around Hotlanta, the pavement guys around here could be seen smiling from ear to ear. The stuff is great, but be prepared to spend some cabbage to buy it.
RE: Asphalt Compaction
You're in Alberta, I am as well. Where are you located? If you are with the Province in Barrhead or Twin Atria, chances are we have met on occasion.
Cheers
KRS Services
www.krs-services.com
RE: Asphalt Compaction
RE: Asphalt Compaction
RE: Asphalt Compaction
Thanks for the greeting. I am a consultant although we have undertaken a significant amount of design and QA work on rehabilitation, reconstruction, and new construction projects over the years with the Province and various municipalities. I'm currently stationed in GP. Hope to see you sometime.