Agree with Ron. Theoretically you should see a conical failure as lateral strain on the top and bottom of the specimen is restricted by friction against the loading plates which would result in bulging of the mid area of the specimen.
Can be a big undertaking to establish and maintain a database. Ground penetrating radar might be the best NDT approach to obtain pavement structure thicknesses although nothing can replace borings or cores where actual road structure thicknesses and subgrade can be measured and categorized.
Interesting input to a simple question. I agree that it is not or at least should not be a spec. It is a terminology thing though, and I run in to the same question occasionally. When proof rolling I like to see a loaded vehicle pass the prepared area in at least 2 directions. Same thing when...
You should monitor the compaction of intermittent lifts. Adequate compaction of material below grade is important to avoid excessive settlement. Testing frequencies are commonly specified by a local/municipal authority or, on private sites, the project specifications. As the others have...
The PCA (Portland Cement Association) has a good guideline for this kind of application.
http://www.cement.org/bookstore/profile.asp?id=235
For supplementary information, I commonly obtain the technical specs for the forklift being considered. The specs will provide the vehicle wt, tipping...
I would only apply nuclear density testing of ACP during construction to help obtain an optimum rolling/compaction pattern or, possibly to obtain a general idea of the compaction in much the same way that rebound hammer results would be applied as a qualitative measure of concrete compressive...
Underpinning, to me, implies that there is an existing foundation requiring additional support to fix a problem or to carry additional load. Perhaps start with defining what the underpinning is to provide and, if known, summarize the soil conditions inherent to the site.
Negative skin friction is usually associated with settling soil relative to a pile that extends through and to depths well below the settling zone. The settling material imposes a downward force on the pile shaft. There are a number of semi-empirical formulas that can be considered to estimate...
Sometimes it is the small add-ons or similar modest projects that can open up unforseen adverse conditions. Former excavations, in-fill, landscaping, old utility trenches, drainage issues, etc. Dry, crusty, poorly compacted fill will settle when moisture softened, no matter how conservative the...
As usual, Ron provides good guidance. I would suggest that 6" lifts are OK with material upto 3/4" in size although you have to be careful with segregation as you lay out the larger sizes.
Thanks for the photo. It would not appear to be a large area justifying a costly testing program. Its hard to get a handle on the depth affected from the photo provided. To rectify the deficiency I would probably have the pavement within and surrounding the affected area ground uniformly to...
BigH - Agreed, the mix, delivery, and placing of RCC are very much the same as CSBC, more powder though. Other than that, not a whole lot different. CSBC was used here for years as the base structure (or component thereof) for road pavements. The main draw back has been seasonal movements in...
We recently cored a segment of ACP along a taxiway subject to fuel spill leaking from a fuel truck (malfunctioning valve) returning to its docking station from the apron after fuelling an airplane. Upon examination of the cores it was amazing to see the depth of impregnation of fuel as the...
