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CALIBRATION SERVICES, INC.
300 Buttertown Road
Emlenton, PA 16373
724-867-6664
ACCREDITED
724-867-1346 Fax

Web: www.calibrationinc.com
Email: info@calibrationinc.com
ISO 17025-2005
Laboratory Accreditation Bureau
CERT # L 1174
Specializing in Service, Calibration, Retrofit, and Sales of Physical Testing Equipment

INSTRUCTIONS FOR TESTING
CONCRETE CYLINDERS USING A COMPRESSION
TESTING MACHINE WITH A CS-100-2A DIGITAL
AND A GREENLEE HYDRAULIC PUMP



November 27, 2007
Author: William W. Stump III

1.

Sample Preparation
Prepare the concrete sample in accordance with ASTM C-39.
Use the capping method of choice.
If using pad caps, be sure to have the appropriate durometer pads in the bases.
Be sure to thoroughly clean the bases on a regular basis both inside and out. Concrete debris will build up on the inside of the steel bases. This will cause excessive corner breaks on samples if the debris is allowed to build up. Use a blunt instrument to remove the debris and reinstall fresh pads.
When using pad caps, the rule of thumb is to break 100 cylinders, flip the pads over test 100 cylinders and throw the pads away. Typical life expectancy of pads is 200 breaks. Over usage of pads will cause unacceptable tests results.
When installing pad caps on the specimen, always put the bottom of the specimen in the bottom pad cap base. The bottom of the specimen is the side which sits in the bottom of the cylinder mold.

2.

Preparing for application of load to the sample
Take your capped specimen and insert it into the testing machine.
Center the specimen in the upper and lower pad bases.
Center the specimen in the testing machine.

If you have a machine with a piston on the top of the loading frame, center the specimen on the top platen.

If you have a machine with a piston on the bottom of the loading frame, Center the specimen on the bottom platen.

This is very important if you want accurate testing results!!!
Your testing machine will have a Digital Display for load indication.

Please review the features of the Digital display before attempting to test samples. This information is found in the Digital Manual.

Each model of digital offers different ways to input critical information regarding your test. If an authorized calibration company is performing setup, please ask to be instructed on digital operation and features at time of setup. If this is not the case….PLEASE READ THE MANUAL.

Your machine is fitted with a CS-100-2A indicator.

This indicator allows for entry of specimen dimensions, this will allow you to show your loading rate in Stress/sec if the rate of loading menu is set up for this function. It is important to enter the proper specimen dimensions prior to testing in order to show the loading rate properly.

C-39 specifies the loading rate at 35 PSI/sec +/- 7 PSI.
When using pad caps, the rule of thumb is to break 100 cylinders, flip the pads over test 100 cylinders and throw the pads away. Typical life expectancy of pads is 200 breaks. Over usage of pads will cause unacceptable tests results.
When installing pad caps on the specimen, always put the bottom of the specimen in the bottom pad cap base. The bottom of the specimen is the side which sits in the bottom of the cylinder mold.

3.

Application of Load
Before applying load to the specimen, it is very important to understand the operation of the control valves on the pump.
The machine in this example has a Greenlee Hydraulic Pump with a Greenlee flow control valve.
The Pump

The Pump uses Dextron III ATF as the fluid of choice.
The reservoir should be ¾ full of fluid.
The vent, located on the back of the reservoir, should be open prior to testing.
The Valve

The valve contains 2 levers and 1 stem.
The lever on the right side of the valve is the pressure/release lever.

In the upright position (with the knob against the motor) the pump will Build pressure.
In the down position (with the knob against the reservoir) the pump will release pressure and allow the piston to retract.
The lever on the left is the rapid advance/controlled rate lever.

With the knob pull toward the operator, and the release lever in the pressure position, the pump is in rapid advance.



This means the piston will move rapidly. Care must be taken when using the rapid advance function. The piston only has 2 ½ inches of stroke. If left in the rapid advance position for too long, the piston will overextend causing a release of oil from the piston area. Immediately shut off the pump and call CSI at 724-867-6664 for proper instruction of how to eliminate this problem.






The rapid advance lever is used only to position the piston close to the sample for zeroing purposes, or to preload the sample once zeroing has been performed. Never use the rapid travel position to test the cylinder to total failure. This will provide inaccurate test results.





With the knob pushed back toward the pump motor (all the way back) the pump will be in the controlled rate position.



All the fluid will be sent through the stem located in the center of the valve. This stem will allow you to set the rate of loading for the machine.
ASTM C-39, for a 6 X 12 concrete cylinder, requires the rate of loading to be 35 psi/sec +/- 7 psi. Calculated in lbs, this comes out to 990 lbs per second +/- 200 lbs.
The stem in the center acts like a water spigot. Counter-clockwise increases the rate of force application per second. Clockwise decreases the rate.
Once the proper rate is achieved, you can leave the stem at that setting and the machine will continue to load at the proper rate.

YOU ARE NOW READY TO TEST YOUR SPECIMEN

Turn on the pump

1.

Put the levers in a loading position.

2.

Pull the RAPID TRAVEL lever towards you to raise the piston until approximately ¼" of daylight exists

3.

IMMEDIATELY move the rapid travel lever completely toward the consol to METERED ADVANCE position. DO NOT MAKE CONTACT WITH THE SPECIMEN YET. If you have then you must release the pressure and go back to step 1.

4.

Wait 3 seconds and Press the ZERO button on the digital display

5.

WAIT 2 to 3 seconds until the load display blinks

6.

Rotate the valve back to RAPID TRAVEL position and preload the sample

7.

Rotate the valve back to the METERED ADVANCE position

8.

Wait for a second or two and view the load rate display which is located directly under the load display on the digital

9.

IF THE LOAD RATE DOES NOT SHOW ON THE BOTTOM OF THE DISPLAY, DUMP THE PRESSURE USING THE DUMP VALVE. DO NOT PROCEED WITH THE TEST. IF YOU DO THE PEAK LOAD WILL NOT BE DISPLAYED AT TEST END. REPEAT THE ZEROING PROCEDURE AT STEP 3

10.

If the rate of load shows up, follow the load rate and keep it at 35 PSI/sec +/- 7 psi.

11.

You may have to turn the star shaped knob on the flow control valve CW if it is too fast or CCW if it is too slow to achieve the proper speed.

12.

Once you get your speed set, leave the star shaped knob in that position. Continue to load the sample until it fails.

13.

You will notice the rate of loading will drop before the sample fails. Do not attempt to compensate during yield.

14.

Unload the machine after failure by using the dump valve

You are now ready to test your next specimen.

 

CALIBRATION SERVICES, INC.

 


300 Buttertown Road
Emlenton, PA 16373
(724) 867-6664 or (800) 793-1870
FAX (724) 867-1346

 

 
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