Air content of fresh concrete is normally measured, by the use of a special air meter, to assess whether the concrete contains the required amount of air. This would be measured when air’s entrapment or entrainment is required by the concrete design. The method uses the principle of replacing the air in a known volume of concrete with water, the volume of which can then be measured.
The apparatus consists of a pressure tight flanged cylindrical measuring bowl of specified volume in accordance with size of aggregate to be tested. The bowl is fitted with a removable flanged conical cover assembly with the help of a airtight sealing gasket. The conical cover has an air valve and a pet cock for bleeding off the water. A transparent cylindrical stand pipe, which is graduated in air content, is fixed to the conical cover assembly.
Pressure is applied to the specimen with the help of pressure bulb and the pressure is recorded on the pressure gauge which is mounted on the stand pipe. The whole assembly is mounted on a flat base.
Calibration cylinder with spring clamp,Trowel,Tamping rod,Straight edge,Rubber mallet andmeasure. – 1 No. each