Concrete Air Content Tester, CA-3 Direct Reading Type

CA-3 type direct reading concrete air content testerOverview:

Used to determine the air content in concrete mixtures, suitable for concrete with aggregate particle size not exceeding 40mm, air content not exceeding 10%, and slump.

This machine has the advantages of easy operation, accurate measurement, and intuitive reading, and is an advanced concrete mixture air content measuring instrument. The measuring method of the concrete air content meter complies with the relevant provisions of GBJ80-85 (Performance Test Method for Ordinary Concrete Mixtures) on the testing of air content in concrete mixtures.

Technical specifications

1. Measuring bowl capacity: 7 liters (with an inner diameter equal to depth)

2. Gas content range: ≤ 10%

3. Particle size of coarse aggregate used: ≤ 40mm

Concrete Air Content TesterScope of application:
Widely applicable to construction, highways, railways, water conservancy and hydropower, ports. Measurement of air content in concrete at various construction sites such as airport construction, supervision and management of engineering quality, and scientific research and teaching experiments on concrete materials.
The stable and accurate measurement results provide reliable data basis for scientific research and testing, and play an important role in controlling the air content of concrete. The simple operation method and concise safety facilities bring convenience to operators, especially in harsh construction environments where the labor intensity is reduced, work efficiency is improved, and construction quality is reliably guaranteed.

HC-7L Concrete Air Content TesterOverview:

This product is used to determine the air content in concrete mixtures, suitable for concrete with aggregate particle size greater than 40mm, air content not exceeding 10%, and slump. The determination method complies with the relevant provisions of GB/T5008-2002 "Test Method for Performance of Ordinary Concrete Mixtures" regarding the air content test of concrete mixtures.

This instrument is widely used for measuring the air content of concrete in various construction sites such as construction, highways, railways, water conservancy and hydropower, ports, airports, etc., supervising and managing engineering quality, and conducting scientific research and teaching experiments on concrete materials. The stable and accurate measurement results provide reliable data basis for scientific research and testing, and play an important role in controlling the air content of concrete. This measuring instrument has the advantages of easy operation, accurate measurement, and intuitive reading, and is an advanced concrete mixture air content measuring instrument.

Technical parameters:

Measuring bowl capacity: 7 liters

Gas content range: ≤ 10%

Large particle size of coarse aggregate: ≤ 40mm

Minimum reading: 0.1%

Design high pressure: 4MPa

High working pressure: 0.4MPa

Airtightness test pressure: 0.4MPa

Weight: 11Kg

Usage:

1. Wipe the measuring bowl and the inner surface of the bowl cover with a damp cloth, and place the measuring bowl horizontally.

2. Evenly pour the fresh concrete mixture into the measuring bowl, so that a small amount of the concrete mixture is removed from the measuring bowl. When loading materials, a tamping rod can be used to slightly insert and compact them. After installation, when using a vibration table (vibration frequency 50Hz, amplitude 0.5 ± 0.1mm when unloaded) to vibrate, if the concrete mixture sinks below the inner mouth during the vibration process, the concrete mixture should be added at any time. The vibration should be stopped when the concrete surface is flat and glazed.

When using a tamping rod instead of a vibration table, the concrete mixture is divided into three layers and compacted. After each layer is compacted, it is about one-third of the height of the measuring bowl. When compacting the bottom layer, the tamping rod should penetrate the entire depth. When inserting the upper layer, the tamping rod should be inserted into the lower layer by 10-20 mm. After each layer is compacted, the tamping rod can be placed at the bottom of the measuring bowl, and the measuring bowl can be alternately shaken left and right on the ground 15 times.

3. After compaction, excess concrete mixture on the surface should be immediately scraped off with a scraper. If there are any depressions on the surface, they should be filled, and then smoothed with a trowel to make the surface smooth and free of bubbles.

4. Clean the edges of the measuring bowl and bowl cover, place the "O" - shaped rubber seal ring (238 × 8.6) in the groove on the edge of the bowl cover, cover the bowl cover, clamp it with a clamp to ensure good airtightness, and check the level with a spirit level.

5. Open the small faucet and exhaust valve, use a water injector to inject water from the small faucet into the measuring bowl until the water flows out from the outlet of the air valve, and then close the small faucet and exhaust valve tightly.

6. After closing all valves, use an air pump to inflate and increase the pressure, making the gauge pressure slightly greater than 0.1MPa.

Note: ⑴ Whenever reading pressure, lightly tap the dial with your fingertips and wait for the pointer to stop swinging before reading.

The 0.1MPa pressure line is the initial pressure line of the instrument, and 0.1MPa is the initial pressure of the instrument.

7. Press the valve 2-3 times and lightly tap the circumference of the measuring bowl with a wooden hammer to evenly distribute pressure throughout the sample. Press the valve stem again and wait for the pressure gauge pointer to stabilize. Measure the pressure gauge reading and obtain the apparent gas content value A1 of the concrete mixture sample measured by the instrument based on the calibrated relationship curve between gas content and pressure reading

After the test is completed:

⑴ Open the vent valve and release air from the measuring bowl. If it is necessary to determine the gas content for the same sample weight, repeat steps 5-7 above.

⑵ Open the small faucet, loosen the clamp, and remove the bowl cover.

⑶ Pour out the concrete mixture sample from the measuring bowl, clean the bowl cover and the inner surface of the measuring bowl.

If the gas content measuring instrument is not used continuously, the fine adjustment valve should be opened to release air and make the chamber pressure consistent with atmospheric pressure.

Note: During the operation, if the air pressure in the chamber is released through the fine adjustment valve and there is still pressure in the measuring bowl, the valve rod cannot be pressed, otherwise water will be sucked into the chamber, causing errors in future testing.

Applicable standards: The product references the following standards:

Test Method for Performance of Ordinary Concrete Mixtures GB/T5008-2002;

Technical Specification for Application of Ordinary Concrete Admixtures GB50119-2002;

Ordinary Concrete Admixtures GB8076-1997;

Test Code for Hydraulic Concrete (DL5150-2001);

Test Code for Cement Concrete in Highway Engineering JTJ053-94.

The gas content is calculated according to the following formula:

A=A1-C

Among them: A-concrete mixture quantity (%)

A1- Instrumental determination of gas content (%)

C-aggregate gas content (%)

Take the average of two measurements as the experimental result. If there is a difference of more than 0.2% between two gas content measurements, the cause must be identified and the test must be redone.