Principle and application of air content in the ho

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Principle and use of air content in mortar

Guide: air content in mortar is used to measure the air content in mortar. The air content of mortar conforms to jgj/t (standard for basic performance test method of building mortar) and jisa1228 and can improve the reproducibility of PD point, which is used to measure the air content in mortar

working principle of air content in mortar

according to the gas equation, between the air chamber with a certain pressure and the container full of test materials, when the opening and closing pressure is balanced, when the pressure of the two containers reaches equilibrium, the amount of reduction in the air chamber pressure is the percentage of the air content in the mortar, and what is shown on the pressure gauge is the air content in the test materials

air content of mortar usage method

1) weigh the empty bowl and record it

2) put the sealing ring on the bowl, and then hang the clamping ring on the frame of the bowl

3) fill the bowl with mortar and shake/compact it

4) uncover the sealing ring and use a big hammer to make the mortar exceed the edge of the bowl

5) weigh the full bowl, and then subtract the recorded weight of the empty bowl to calculate the bulk density

6) now clean the edge of the bowl with a clean cloth

7) put the upper part on the cleaned bowl, and then fasten the clamps around

8) open the stop valve and the control lever is up. Then use the washing bottle to inject water into the stop valve until the water overflows from the stop valve and there are no bubbles

9) turn the left semicircular handle to turn on the air pump until the pointer of the pressure gauge points to the position 3 below "%air". Now slowly turn the screw of the exhaust valve to the left until the pointer of the pressure gauge accurately points to "%3 below air". If you point to this position, please turn the screw clockwise to close the exhaust valve. ("%3 position below air", that is, the initial pressure point, has the same effect as the air content of concrete.)

10) close the stop valve

11) when the pointer returns to zero, start to check that its size is within a specific range or the range specified in the standard. Press the rocker for about 20 seconds until the pointer of the pressure gauge stops moving

12) directly read the percentage of air content on the pressure gauge

13) slowly open the stop valve. Then turn the screw to the left to release the excess pressure

14) open the upper part, empty the bowl, then clean it, and wipe all parts dry

air content test method of mortar:

1. Put the mixed concrete into the bowl twice,

2. Vibrate separately, eliminate bubbles, scrape off the excess part of the surface,

3. Cover the cover, and screw the compression valve lining evenly. If there is a torque value, close all valves

4. Inflate to ― with the inflation valve. Point position, stop for seconds,

5. Press the air inlet valve, and the position indicated by the gauge needle is the measured value of the air content of the concrete (red)

6. After the measurement, slowly loosen the pressure regulating valve,

7. Slowly return the gauge needle to the zero point, and do not loosen it violently, so as to prevent the pointer from hitting the zero point positioning column and affecting the accuracy

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