Air Entrainment Meter (also known as Air Content Meter) line from QUALITEST-TESTING, is widely used to measure the air content of freshly mixed mortar and fresh concrete in accordance with the air pressure compensation principle. The Air Entrainment Meter has a pressure chamber in which a predefined pressure is generated. When the overflow valve is opened, the pressure is compensated with respect to the test pot, which is filled with the freshly mixed mortar. The pressure drop is measured to give the air content in the mortar.
Air entrainment is the intentional creation of air bubbles in concrete or mortar. Excess water is often trapped within the mix as it hardens. The excess water eventually evaporates and leaves behind porous cavities. These pores create weaknesses in the concrete or mortar during freeze-thaw cycles. An air entrainment meter is used to measure the amount of air that is trapped within the mix. The sleek design of each of these units allow for easy storage on top of any workstation.
Qualitest offers Air Entrainment meters in different capacities adhering to DIN EN 459-2; DIN EN413-2; ASTM C 185 and other international standards. These meters are either with a sturdy hand-operated pump or with an electrical mini compressor for rapid and uniform provision of pressure.
To improve the workability of mortar and concrete mixtures, and to enhance the durability of mortar and concrete under conditions of frost and thawing weather conditions, admixtures are mixed in with the concrete during its preparation that promote the development of air voids (air entrainment). If properly applied, this technique can achieve an optimum in the feasible technological enhancement of the concrete mixture in the total volume. Frequent tests are essential in order to maintain at a constant level the air entrainment level that has been determined as optimal for a particular kind of concrete. The air entrainment meters being described here monitor the effects of air-entraining admixtures. These air entrainment meters measure the air void content in fresh concrete and directly show this content on a pressure gauge in percent.
The Air Entrainment meters are made of cast aluminum; locking bolts with palm grip give the test pot and upper section an airtight seal. The air is compressed by means of a built-in hand or electric pump. The connection valve for the initial pressure and the overflow valve are integrated into the pressure chamber. The connection valve is a sensitive needle valve with a knurled head screw. The over flow valve for the pressure compensation between the pressure chamber and the test pot is operated by means of a valve rocker. The pressure valve is installed directly on the pressure chamber and the scale shows readings with a range of 0-100 vol %.
Air Entrainment Meter - Air Content Meters For Freshly Mixed Mortar & Masonry Cement
Air Entrainment Meter - Air Content Meters For Freshly Mixed Concrete
The purpose of this test method is to determine whether or not the hydraulic cement under test meets the air-entraining or non-air-entraining requirements of the applicable hydraulic cement specification for which the test is being made. The air content of concrete is influenced by many factors other than the potential of the cement for air entrainment.
For testing freshly mixed mortar and masonry cement, have been designed and built in accordance with the following standards: DIN EN 459 T.2, DIN 18555 T.2, and ASTM C 185. To improve the workability of the mortar mixture, and to enhance the durability of mortar under conditions of frost and thawing weather conditions, admixtures are mixed in with the mortar during its preparation that promote the development of air voids. If properly applied, this technique can achieve an optimum in the feasible technological enhancement of the mixture of air and mortar in the total mortar volume. Frequent tests are essential in order to maintain at a constant level the air entrainment level that has been determined as optimal for a particular kind of mortar. This Air Entrainment Meter monitors the effects of air-entraining admixtures for the specified mortar mixtures. The purpose of this series of Air Entrainment Meters is to measure the air entrainment (air-void content) of fresh mortar. The pressure gauge gives a direct reading of the air content in per cent (%).
This test method covers the determination of the air content of freshly mixed concrete. The test determines the air content of freshly mixed concrete exclusive of any air that may exist inside voids within aggregate particles. For this reason, it is applicable to concrete made with relatively dense aggregate particles and requires the determination of the aggregate correction factor.
This test method and Test Method C 138/C 138M and C 173/C 173M provide pressure, gravimetric, and volumetric procedures, respectively, for determining the air content of freshly mixed concrete. The pressure procedure of this test method gives substantially the same air contents as the other two test methods for concretes made with dense aggregates.
The air content of hardened concrete may be either higher or lower than that determined by this test method. This depends upon the methods and amount of consolidation effort applied to the concrete from which the hardened concrete specimen is taken; uniformity and stability of the air bubbles in the fresh and hardened concrete; accuracy of the microscopic examination, if used; time of comparison; environmental exposure; stage in the delivery, placement, and consolidation processes at which the air content of the unhardened concrete is determined, that is, before or after the concrete goes through a pump; and other factors.