Remember to rev the truck 30 rotations after the addition of on-site water or plasticizer. There is no problem with tuning in your load like this, as long as you get those revs and test after words.
I would immediately check the calibration of the equipment at the testing lab, then the supplier (sounds like you may not have all the cement you are paying for). 1500 psi is very very odd. Start using a 3,000 or 4,000 psi mix and save yourself real money.
I assume that the hole in your bottle is the limiting factor, not the liquid outlet. Cut the end off of your bottle which should produce the maximum possible flow rate. Time how long it takes to empty the bottle with a huge hole (you know the volume). Back into the size of your hole based on...
The posts above show the definition of each varies for different projects. Check contract documents/agreements or your management, not your specs, for the answer and how it applies to your task.
Have to agree strongly with earlier post. Don't waste time trying to calculate, call the local quarries and find out the real answer to the truck/weight question. Do not rely on DOT restrictions.
Run some ASTM D 1196, static plate load tests on the subgrade and see if the results suit your applicaiton. Suggest multiple tests to get data on various depths of fill. If subsurface water levels vary seasonally, perform testing when the levels are highest. Install settlement markers. Have...
Check out the American Concrete Institute (ACI) 224.3R concerning contraction joints. As Ron stated previously, you won't find absolute guidance in the ACI but will find a few standard sections and reccomended advice. Also, many state/municipal websites offer standard drawings online for...