Base Course for Asphalt Parking Lot
Base Course for Asphalt Parking Lot
(OP)
I have a client who is interested in using asphalt grindings as the base course material for a new asphalt paved parking lot. Lot size is a little over an acre. Wondering if anybody has done this before. My concerns are getting it compacted well enough and it's longevity/durability. Should typically see just passenger vehicle traffic and box delivery trucks occasionally. Very few if any semi-truck traffic is expected. Also, what thickness would you suggest?





RE: Base Course for Asphalt Parking Lot
You cannot use typical moisture density relationships (Proctor), because you will not be able to accurately establish a moisture relationship. Determining the moisture content of the material is fleeting and somewhat irrelevant, unless it is mixed with soil. Even then it is difficult to get repeatability.
If you stabilize with asphalt emulsion, some soil and the millings, you will create an excellent base, but your whole criteria of acceptance will change from a soil based premise to one of asphalt.
Alone, the millings are not stable enough to use as a base material.
Do some analysis on your pavement loads to determine the proper thickness you will need.
RE: Base Course for Asphalt Parking Lot
With the processed material, usually the top screen size is either 1/2" or most likely 3/8" and this does not make for a good base material, there is not enough larger aggregate in the composition.
If the material came straight from the mill, the material will be too inconsistent. You can get large chunks as well as the fines. Also, if the milled material was stockpiled, the heat can bind the millings back together and then you can get even larger chunks, that do not break down easily.
It sounds like your client is trying to save money, where I am from in the Eastern US, millings, when we do sell them (we typically use them for RAP in our asphalt plants), are half the price of a good base material. Trying to manipulate the material as Ron has stated may work, but it will be a lot of work and in the end would likely be more costly and as stated above, hard to get repeatability. Also, the reclaimer used to for this type of work really is not set up for a small lot.
As for thickness, again as Ron stated, you will need to do some analysis of the pavement loads and I might add you will also need to know the underlying material's CBR value.
RE: Base Course for Asphalt Parking Lot
RE: Base Course for Asphalt Parking Lot
That's a good suggestion, I will check into that in the upcoming week. Thank you.
RE: Base Course for Asphalt Parking Lot