Warm Mix Asphalt

[Road Guy]

Anyone have any stories, success, failures with it?

Is there a decent cost savings compared to standard asphalt?

 

[ktulu]

RG,

I performed the first US lab evaluation of WMA technologies (ADVERA, Sasobit, and Evotherm) while I was at NCAT. Shoot me a PM and I will give you my work number if you want to discuss. My new firm recently wrote the WMA Best Practices Manual (NAPA QIP 125). And I actually wrote my Master's thesis on WMA.

As for cost savings versus HMA, there is a study going on right now (I am not sure if it's under confidentiality or not, so I will not say who) that is looking at cost savings in depth.

I think that Georgia mainly looking at WMA as a compaction aid. At least that's what Peter Wu with GDOT has told me.

The only "failure" that I have heard of was in Georgia, near Macon. But IMO it was more of a hesitation to adapt than a WMA problem. Every other field trial that I have heard of (more than 60 across the US) have been successes.

Cement has some field experience with WMA. He can give more details as to what he saw.

ktulu

 

[cement]

We did three test sections of 1000 tons each last summer to determine the feasibility of WMA for lower temperature applications that are common at higer altitudes and that are found at night, since our work is increasingly required to go at night because of congestion during daylight hours. This was particularly of interest for my office since the standard specified 50 degree paving temperatures are only reliable for a short window during the summer, when traffic counts are the highest.

The three sections tested different WMA products, with control sections of standard superpave mix tostart each night's production. All three sections appear to be holding up quite well after a severe winter, with over 100 chain law days. A research paper will be done this summer, I will post the link when it becomes available.

We used the same mix design as the rest of our resurfacing project, and addedthe admixture at about 1% and produced at 50 to 100 degrees lower temperature. The ambient temperature for construction did not cooperate though, it was pretty mild those three nights! We used the same roller pattern that was established for the regular mix, but the operators had a bit of a learning curve as the they got on the mat a little too soon sometimes since they could not see the classic fume cloud to gauge temperature. Probably good that!

the report is mostly done and will be posted here

We had lots of interest from industry and other agencies, I hope it works out!

 

[FLBuff PE]

We did three test sections of 1000 tons each last summer to determine the feasibility of WMA for lower temperature applications that are common at higer altitudes and that are found at night, since our work is increasingly required to go at night because of congestion during daylight hours. This was particularly of interest for my office since the standard specified 50 degree paving temperatures are only reliable for a short window during the summer, when traffic counts are the highest.
The three sections tested different WMA products, with control sections of standard superpave mix tostart each night's production. All three sections appear to be holding up quite well after a severe winter, with over 100 chain law days. A research paper will be done this summer, I will post the link when it becomes available.

We used the same mix design as the rest of our resurfacing project, and addedthe admixture at about 1% and produced at 50 to 100 degrees lower temperature. The ambient temperature for construction did not cooperate though, it was pretty mild those three nights! We used the same roller pattern that was established for the regular mix, but the operators had a bit of a learning curve as the they got on the mat a little too soon sometimes since they could not see the classic fume cloud to gauge temperature. Probably good that!

the report is mostly done and will be posted here

We had lots of interest from industry and other agencies, I hope it works out!

I work for a statewide firm that performs materials testing and construction obs. (among geotech and environmental engineering services), so I'll be interested to read the report. Can you disclose where the section is? If not, no big deal.

 

[cement]

the CDOT report? if you dig a little deeper in the research section, you can see it is listed as 95% done. it will be posted at the link I gave above when completed.

hey FLBuff, you going skiing at Aspen this weekend? Tempting!

 

[FLBuff PE]

the CDOT report? if you dig a little deeper in the research section, you can see it is listed as 95% done. it will be posted at the link I gave above when completed.
hey FLBuff, you going skiing at Aspen this weekend? Tempting!

Yeah, it was tempting, but I decided that with Food and Wine in town, with highs in the 80's, and evryone and their brother trying to get runs in on 12 runs, I did not feel the need. I went road biking up to the Maroon Bells instead. And meant the section of road that was wma, not the rpeort itself. I didn't see the report posted, so I'll dig deeper. Thanks!

 

[Road Guy]

thanks cement, will take a look at it.

Anyone had any success with other resurfacing methods?

Hot in Place? (for subdivision streets and low traffic roads only)

The ACI was the highest ever this month and something has to give....

 

[cement]

we do hot in place on the interstate, but it has fallen out of favor lately. It is capped with vigin mix usually, and the extra thickness requires resetting the guardrail.

the problem with the hot in-place is the variable material, and those damn geotextiles ldman:

I heard we set a road with rubberized asphalt on fire once.