Air Content In Concrete Pressure Meter Method

The assembled meter with cover is filled with water removing all entrapped air.

Air content in concrete pressure meter method.

Once the valve is depressed and held equalization occurs when the known air in the air chamber releases into the unknown air content in the concrete sample in the bowl below. Two types of pressure method air meters. This is carried out by means of a column of water over the known volume of concrete. The differences between air content measurements by the two methods were within 2 percentage points.

Later drilled cores were taken from the pavement at approximately the same location as the samples. Overview of astm c231 standard test method for air content of freshly mixed concrete by the pressure method this is a test required to pass the american co. Pressure methodaci technician workbook cp 1 aggregate testing limitations th. Type a meter helps in the direct measurement of the change in volume in the concrete.

Pump air into the pressure meter until you have reached this line. Concrete pressure method. You are filling it so the only air present inside the meter is the air that s inside the concrete. Uses pressure to displace water into concrete.

The results show that the pressure meter and astm c457 measurements of concrete cylinders were in reasonable agreement. We think the pressure method is most reliable for normal weight concretes provided that you keep the air meter in calibration and use the aggregate correction factor. Every air meter has its own calibrated initial pressure value. After closing the petcocks the pressurized air is released into the bowl using the needle valve lever.

Csa a23 2 4c. Uses equalization to determine air content in the concrete. Testing for air content in plastic. Place the representative sample of concrete in the measuring bowl in three equal layers consolidating each layer by rodding 25 times.

In the gravimetric method air content is determined based on differences in actual and theoretical air free unit weights of the concrete. The air chamber is pressurized by pumping until the gauge needle stabilizes at the initial pressure line. Astm method of air content measurement in concrete the astm test method for pressure air measurement specifies two meters to measure the air content.