One Dimentional Consol AASHTO T216 / ASTM D2435

[Jaden1017]

I was told I needed a Screw Arm for my loading apparatus but I read Both AAshto and ASTM Methods but I cant find anything on either that say its required. I can't find anything that remotely says a screw arm was needed... Does anyone have any idea where in these methods it says we need a screw arm?

 

[emmgjld]

The old (I mean old!!!) machines used a screw assembly to move the loads on the lever arm. Many machines have a set lever length and predetermined weights are applied, as required.

Automated equipment uses 'stepper' motors to apply the load, controlled by a load cell.

 

[BigH]

Ah, but I like those old Wykham Ferrance consolidation set-ups!! Simple and effective. When I was in Guyana, they bought one with a motorized self-leveling arm - waste of money - no one knew how to maintain, use or repair. KISS was needed but they got Snafu'ed.

 

[emmgjld]

I actually remember the equipment when wandering around my Father's lab in Colorado Springs, in the late '50s. It was fascinating to this young lad. This was back in the days when knowing a good machinist was important. My Father built his own Triaxial setup, and most attachments for the misc. compression/tension testing and his first Hveem Compactor.

The disassembled remains of an old T&O concrete compression machine comes to mind. Actually, I think the consol equipment was also T&O, but a mind can be a frightful thing to put to use.

Actually, the old equipment consol was extremely versatile.
The present equipment is quite limited in how the tests are run and require some real thought if doing testing 'outside the box'. I have gotten back much of that versatility by going to automated consol and direct shear machines.

 

[Jaden1017]

Well basicly I was told that My loading device does not have a screw arm installed in the apparatus to permit quick application of a given load increment without significant impact to the test specimen there for it is out of spec.

Now I used to have an ELE version for my consol that had a screw arm underneath the loading arm to suspend the arm before the intial loading on to the sample. Although i found the part convenient I still dont understand why my equipment requires it. Specially when I could not find it in either ASTM or ASSHTO. Unless I missed it and if I did does anyone know where it is in either ASTM or ASHHTO books?

 

[emmgjld]

I went back over the ASTM D-2435 and could find no requirement for a 'screw arm'. I do not remember anything new coming through the ASTM D committee regarding this test. I am afraid that I can be of no help. I appear to read the ASTM the same way you do. I would ask for a specific sketch, photo or reference to a machine model/manufacturer.

 

[BigH]

Jaden1017 - by the way, who told you? and does it matter?

 

[Jaden1017]

Who told me? The funny part is its AMRL assesment. The AMRL Rep told me. But when I asked where in the ASTM its located she could not find it and told me to find out myself. So I've done my research and could not find anything even called the manufacturer of my consol apparatus and they did not find anything as well. So before I go to AMRL and say they dont know what i'm talking about. It was more prudent if i dig a little further.

 

[emmgjld]

Ah Yes, The checkers are now running the show.

My rule has always been---Show Me!! Prove Yourself!!

I remember an experience with CCRL a few years ago. Do to timing, we ended up with 2 inspectors, to get our lab checked in short order. They got into an argument , over something inconsequential. My techs loved it. They left, not speaking to one another. I was expecting a minor addition to my bill ... the price of admission to one of the best side shows in the area.

 

[Stoph]

AASHTO T-216, Section 6.1 Load Device says "...should permit quick application of a given load increment without significant impact."

AMRL must be assuming that a screw arm is the only way to accomplish this because their own inspection worksheet only states that Load Device "permits quick application of a given load increment without significant impact."

 

[Jaden1017]

Well I have been in contact with one of their quality annalist and after I brought this up I stopped getting any responce. Also the screw arm is only beneficial at first loading. It suspends the loading arm and allows you to lower it very slowly. I admit it is a convinience but does not affect the apparatus unless your throwing the weights on when you load. But if you place the intial load slowly you can get the same effect.

 

[BigH]

yes - checkers don't like to be checked!! Is it surprising? I see putative safety people writing comments like "you need shoring" and they have no technical knowhow at all - it wasn't even classified as an excavation since it was at the toe of a slope. Go figure; but life's a beach - or should be.