(Roller Meter) Volumetric Air Meter Method ASTM C173 on How To Run A Concrete Air Test
How To Run A Concrete Air Test, (Roller Meter) Volumetric Air Meter Method – ASTM C173
Procedure To Run a Concrete Air Test, (Roller Meter) Volumetric Air Meter Method
Today, we’d like to demonstrate how to preform the concrete air test and find the air content of concrete according to ASTM C173
Step 1: Tools Needed
Tools required for this test are the appropriate size mallet, a concrete scoop, a strike off bar, a 5/8 inch diameter tamping rod with hemispherical ends, a volumetric air meter, and 70% isopropyl alcohol.
Step 2: Start the Test
Collect your concrete sample according to ASTM C172. To start the test, dampen the inside of the bowl.
Step 3: Fill Concrete inside Volumetric Air Meter Bowl
Using the scoop, fill the bowl with concrete in two equal layers.
Step 4: Fill the first layer half way
Moving the scoop around the perimeter of the bowl, fill the mold approximately half of its volume.
Step 5: Rod the layer 25 times
Rod the layer 25 times, making sure you distribute the rods uniformly over the cross section.
Step 6: Tap the outside of the pressure meter bowl
Tap the outside of the mold 10 to 15 times with a mallet to close the voids left by the tamping rod.
Step 7: Fill the bowl completely with concrete
Use a scoop to completely fill the pressure meter bowl with concrete.
Step 8: Rod the layer 25 times
Rod the layer 25 times, making sure you penetrate the first layer by about one inch.
Step 9: Tap the outside of the pressure meter bowl
Distribute the rods uniformly over the cross section. Tap the outside of the mold 10 to 15 times with a mallet to close the voids left by the tamping rod.
Step 10: Strike off excess concrete
Strike off excess concrete with a strike off bar.
After tapping with the mallet, a slight excess of concrete above the rim is acceptable. Add or remove concrete as necessary.
Step 11: Wipe the flange of the bowl clean
Once you wipe the flange of the bowl clean, then you need to dampen the inside of the top half of the meter.
Step 12: Attach top half to the bowl
Then attach the top half of the meter to the bowl, creating a watertight seal. Fasten the clamp. Insert the funnel into the air meter.
Step 13: Add funnel
At this point, insert the funnel into the air meter.
Step 14: Add Water
Then add approximately 500 milliliters or one pint of water.
Step 15: Add isopropyl alcohol
Next add the isopropyl alcohol. Most tests require about a thousand milliliters or two pints.
Step 16: Add remaining water
Then add additional water until it appears in the neck of the top section, near the zero mark.
Step 17: Remove Funnel
Then remove the funnel from the neck of the top half of the volumetric pressure meter.
Step 18: Adjust the liquid level
After that, you need to adjust the liquid level with the syringe by adding a removing liquid until the bottom of meniscus is level with the zero mark.
Step 19: Attach the cap
Next you need to attach and tighten the cap, producing a watertight seal.
Step 20: Invert the pressure meter
Quickly invert the meter, shake the base, and return the meter to the upright position. Do not invert the meter for more than five seconds at a time, repeating this process for a minimum of 45 seconds.
Step 21: Place the concrete pressure meter on a solid surface
Next, place the meter on a solid surface. Tilt the meter approximately 45 degrees. Vigorously roll the meter a quarter to a half turn, forward and back several times, quickly starting and stopping the roll.
Step 22: Turn the base a third turn
While you are rolling the meter a quarter to a half turn, turn the base a third turn and repeat the rolling procedure for approximately one minute. If at any time the liquid is leaking, the test is invalid.
Step 23: Loosen the cap
Next you need to loosen the cap and allow the liquid level to stabilize. The liquid level is stable when it does not change for more than 0.25% within a two minute period.
Step 24: Initial meter reading
Then watch to see If the liquid level does not stabilize within six minutes, the test is invalid and you will have to rerun the test with a new sample using additional alcohol. If there’s more than 2% foam in the neck, the test is invalid. When the liquid level is stable, read the bottom of the meniscus to the nearest 0.25%. This is the initial meter reading.
Step 25: Retighten the cap
After you get your initial meter reading you then need to retighten the cap and repeat the rolling procedure.
Step 26: Second rolling procedure
Next you need to vigorously roll the meter a quarter to a half turn, forward and back several times, and repeat the rolling procedure for approximately one minute.
Step 27: Set the meter upright
Once you are completed rolling the pressure meter set the meter upright, loosen the cap, and allow the liquid level to stabilize.
Step 28: Liquid level not visible
If by chance the liquid level is not visible, add calibrated cups of water to the meter.
Step 29: Add calibrated cups of water
Continue to add calibrated cups of water, until you can see the liquid.
Step 30: Record amount of cups of water added
Then Record the number of cups of water added. After the liquid level has stabilized, and our results are within 0.25% of the initial read. Record the result, this is the second and final reading.
Step 31: Air changes by more than 0.25%
If the second reading differs from the initial reading by more than 0.25%, record the second reading and repeat the rolling procedure.
Step 32: Third rolling procedure
Since the second reading differed from the first by more than 0.25%, you will need to vigorously roll the meter for a third time, rolling a quarter to a half turn, forward and back several times, and repeat the rolling procedure for approximately one minute.
If the third air test reading of the liquid level has not changed more than 0.25% from the second meter reading, record the third reading as the final. Otherwise, the test is invalid.
Step 33: Before dissembling the base
Before dissembling the base, pour out the liquid.
Step 34: Remove the clamp
Then you need to remove the clamp.
Step 35: Remove the lid
Next you need to remove the lid.
Step 36: Discard the concrete
Afterwards you need to discard the concrete that is left in the pressure meter bowl in your wheelbarrow or alike.
Step 37: Invalid test
Examine the base for portions of undisturbed, tightly packed concrete. If such material is present, the test is invalid.
Step 38: Valid test
Examine the base for portions of undisturbed, tightly packed concrete. If such material is NOT present, the test is valid.
The air content is equal to the final meter reading, minus the correction for large amounts of alcohol. Plus the number of calibrated cups of water added. Report the air content to the nearest 0.25%.
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