Asphalt alligatored: Crush & Shape or Mill & Cap?

vtsnowedin · Jun 11, 2014

A durable fix though not a cheap one is to pulverize all the existing pavement along with part of the six inch agg. layer. Then spread trap rock (or whatever you call it locally) 1 -1/2" to #4 at the rate of 0.17 tons per square yard over the surface and mix it in with another pass of the reclaimer. Then repave with two one and a half inch lifts of half inch top mix. You will end up about six inches higher then you started. In places where you have to match edge grade cut out and remove enough material to make room for the new stone and pavement before you add the stone.
The reclaimer should cost about $1.50 per square yard, the stone $3.75 and three inches of new pavement $16.24 for a total of $21.50 per square yard. More of course if your lot is small with a lot of odd corners etc.

Egon · Jun 11, 2014

A few core samples should tell you what is going on. Then base a repair on that information.

With costs being consider the chances are milling some off and adding a top lift will be your preferred choice.

paulharvey · Jun 11, 2014

vtsnowedin said:
A durable fix though not a cheap one is to pulverize all the existing pavement along with part of the six inch agg. layer. Then spread trap rock (or whatever you call it locally) 1 -1/2" to #4 at the rate of 0.17 tons per square yard over the surface and mix it in with another pass of the reclaimer. Then repave with two one and a half inch lifts of half inch top mix. You will end up about six inches higher then you started. In places where you have to match edge grade cut out and remove enough material to make room for the new stone and pavement before you add the stone.
The reclaimer should cost about $1.50 per square yard, the stone $3.75 and three inches of new pavement $16.24 for a total of $21.50 per square yard. More of course if your lot is small with a lot of odd corners etc.

I agree, except I have no idea what trap rock is. You can add asphalt emulsions to the mix or Portland cement. Neither is a cheap method,, and few "site" contractors have the equipment. Around here only about 3 out of 5 road builders have reclaimers; and almost none of the site/parking lot types do. And those prices sound about right for 5000 square yards and up; but would be a lot higher for a 100 Sq yard lot.

vtsnowedin · Jun 11, 2014

paulharvey said:
I agree, except I have no idea what trap rock is. You can add asphalt emulsions to the mix or Portland cement. Neither is a cheap method,, and few "site" contractors have the equipment. Around here only about 3 out of 5 road builders have reclaimers; and almost none of the site/parking lot types do. And those prices sound about right for 5000 square yards and up; but would be a lot higher for a 100 Sq yard lot.

Trap rock is hard durable stone made from blasted and crushed bedrock. it has sharp edges from the crushing process that keep the the layer interlocked under load instead of rolling around like marbles as in river or glacier polished material. It's hardness keeps it sound through repeated freeze thaw cycles where other softer rocks turn to mush. In short "the good stuff". Adding Portland cement is a waste of time and money as it works against the asphalt cement in the old pavement and can create a slab with joints problem that makes frost heaves much worse then other options. Adding asphalt emulsion or cut back asphalt is also of dubious worth as you are not trying to make a pavement out of the base but a superior base. When you brake up an old pavement you are limited by the maximum size of the original aggregates. Unless you are talking an old interstate pavement the maximum size is most certainly one half inch and the reclaiming process breaks down those aggregates so if you removed the residual asphalt and screened the remainder you would have a material that passed for sand, not gravel or crushed gravel. you need to add the missing parts, not hope some extra glue can hold together the wrong parts. The 1.5 inch to 0.25 inch hard crushed rock is what is missing. You are right about the difference between small jobs and main line construction. It dose cost a minimum amount to move the required machinery to a job site so there is a point where it would be cheaper to just have the small contractor to just remove everything that is there and replace it with new material, but times are tough and some of these machines are sitting idle so a cash customer might get a very competitive price. Don't expect anyone to understand the adding stone component though, it hasn't made it's way through the bureaucratic maze. They are happily specifying things like Portland cement and micro seals that have been shown to not work but still have support at the highest levels.

square1 · Jun 12, 2014

I think I now have just enough knowledge to be dangerous! Thanks

Not to slight anyone, but would the contributors from the northern US & Canada mind if I asked about your credentials. I think presenting these findings as from "a 20 year business owner/asphalt contractor in the Northeastern US", "a PE / Civil Engineer specializing in highway design from the Pacific Northwest" or "an Asphalt Supplier from Canada" would hold more sway then saying "some guys on the internet"

I appreciate the input from the southern States as well, but the freeze thaw conditions we share up here are a different animal than the torture your applications have to endure from sun & heat.

Thanks again, you all have been very helpful :drink:

vtsnowedin · Jun 12, 2014

square1 said:
I think I now have just enough knowledge to be dangerous! Thanks

Not to slight anyone, but would the contributors from the northern US & Canada mind if I asked about your credentials. I think presenting these findings as from "a 20 year business owner/asphalt contractor in the Northeastern US", "a PE / Civil Engineer specializing in highway design from the Pacific Northwest" or "an Asphalt Supplier from Canada" would hold more sway then saying "some guys on the internet"

I appreciate the input from the southern States as well, but the freeze thaw conditions we share up here are a different animal than the torture your applications have to endure from sun & heat.

Thanks again, you all have been very helpful :drink:

Thirty two years with the NH DOT as a technician and contract administrator.

Egon · Jun 12, 2014

square1 said:
I think I now have just enough knowledge to be dangerous! Thanks

Not to slight anyone, but would the contributors from the northern US & Canada mind if I asked about your credentials. I think presenting these findings as from "a 20 year business owner/asphalt contractor in the Northeastern US", "a PE / Civil Engineer specializing in highway design from the Pacific Northwest" or "an Asphalt Supplier from Canada" would hold more sway then saying "some guys on the internet"

I appreciate the input from the southern States as well, but the freeze thaw conditions we share up here are a different animal than the torture your applications have to endure from sun & heat.

Thanks again, you all have been very helpful :drink:

Knowledge; I'm afraid mine has been slowly falling by the wayside as the years build up.

Do have CET credentials from back in the sixties. ( not bright enough to be an engineer ) Spent five years working for a General Contractor involved in railway grade construction, highway construction and general road/sewer/water line construction. Did a variety of things, whatever was called for, as I was on salary. That meant very long hours and being the lowest paid fellow out on site.

Did learn that soft ground is different than muskeg and sticky wet clay handles a lot different than shot rock.

Asphault was hot, sticky and gave off a lot of fumes. Heaven
help you if the sub grade could'nt keep ahead of the plant. No matter what the clothes and truck could attract the stuff from miles away.

Concrete was heavy, required sub grade on the money as it was expensive and there were always inspectors taking samples so things like adding water and truck time might have to require so inventive thinking. It also sticks to every thing.

Deep trenching was just plain scary even with proper shoring and carefully following all the safety guidelines.

The dream was a competent operator in # 16 finishing sub grade ! Or a fellow on the chute that knew his business. Or any and all the other competent folks that made a job go easy!

And yes, I'm just some guy from the internet with vague memories and even a tale or two about the shenanigans construction involved.

adirondackmtnman · Jun 12, 2014

square1 said:
I think I now have just enough knowledge to be dangerous! Thanks

Not to slight anyone, but would the contributors from the northern US & Canada mind if I asked about your credentials. I think presenting these findings as from "a 20 year business owner/asphalt contractor in the Northeastern US", "a PE / Civil Engineer specializing in highway design from the Pacific Northwest" or "an Asphalt Supplier from Canada" would hold more sway then saying "some guys on the internet"

I appreciate the input from the southern States as well, but the freeze thaw conditions we share up here are a different animal than the torture your applications have to endure from sun & heat.

Thanks again, you all have been very helpful :drink:

NYCMA certified asphalt quality control technician, as well as NPCA/ACI PCC concrete certified with 8 years experience in design, testing, adjustment and application of superpave and marshall mix designs. I live in the adirondacks of northern new york, working for the area's largest asphalt and concrete supplier. Our three person team is responsible for 7 quarries, 8 concrete plants, 7 asphalt plants, and numerous sand and gravel operations. I've been responsible for meeting the quality control requirements for many, many thousands of tons of mix, my biggest year being over 170,000 Ton supplied to a single job on Interstate 87 in northern NY in 2009. I can smell the asphalt oven as I write this. It's what I eat, sleep, and breathe. While I don't claim to know all there is to know, my knowledge puts the food on the table for my kids.

Sent from my LGL35G using TractorByNet

paulharvey · Jun 12, 2014

square1 said:
I think I now have just enough knowledge to be dangerous! Thanks

Not to slight anyone, but would the contributors from the northern US & Canada mind if I asked about your credentials. I think presenting these findings as from "a 20 year business owner/asphalt contractor in the Northeastern US", "a PE / Civil Engineer specializing in highway design from the Pacific Northwest" or "an Asphalt Supplier from Canada" would hold more sway then saying "some guys on the internet"

I appreciate the input from the southern States as well, but the freeze thaw conditions we share up here are a different animal than the torture your applications have to endure from sun & heat.

Thanks again, you all have been very helpful :drink:

County Engineering Inspector in North Florida for 4.5 years, another 5 years in general site work. Couple FDOT certs, but more experience and sense than paper. I know nothing about freeze thaw stuff. Probably been lead inspector on $20-30m worth oof road work.