Watts Press-Ur-Concrete Air Meter ASTM C231
The original Watts Press-Ur-Meter, w/Wood Case tests the percentage of air in a fresh concrete sample by measuring the air bubbles present. The test method is based on Boyle’s Law and releases a known volume of air at a known pressure into the concrete sample which contains an unknown volume of air. The resulting change in the sample’s volume is directly related to the percentage of entrained air in the sample and can be read off the gauge. Made with the highest quality components for years of service.
The air contents are measured by the method which gives consistent and accurate readings. These readings are important for both fresh and hardened concrete quality and durability.
Dimensions and accuracy exceeds ASTM. Includes: Calibration Vessel, Calibration Tubes, 24in (610mm) Tamping Rod, Aluminum Straightedge, Water Syringe, Carrying Case and instructions. Cast aluminum chamber is 1/4ft3 and can also be used for unit weight and yield determinations. Aggregate correction factor can be determined by this method.
Meets Test Methods: AASHTO T152 ASTM C 231
What is the Watts Press-Ur-Concrete Air Meter ASTM C231 Test Method and Why?
The Watts Press-Ur-Concrete Air Meter ASTM C231 is a device to measure air voids in freshly mixed concrete. It’s an important tool to check the quality of concrete and ensure it meets industry standards. The air meter ensures the concrete has been mixed properly and has enough air voids for proper curing and strength development. With this device contractors can ensure their projects are built with high quality concrete materials. ASTM C231 is not applicable to nonplastic concrete used in the manufacture of concrete masonry units. These concrete masonry units mde from freshly mixed concrete exclusive testing is needed for regulatory limitations prior to usage.
The test method and theory behind the Watts Press-Ur-Concrete Air Meter is to measure air content in fresh and hardened concrete which can vary due to consolidation methods and environmental exposure.
The pressure method gives the same air content as other methods for concrete with dense aggregates.
The test method for air content of freshly mixed concrete by pressure method is a fundamental in concrete quality testing. This is a standard procedure to measure the air content which affects the durability and strength of the concrete.
The pressure method test measures the air content of freshly mixed concrete exclusive of any air that may be in the voids within the aggregate particles. This method is suitable for concrete with relatively dense aggregate particles. A part of this process is to determine the aggregate correction factor which accounts for the air in the aggregate particles themselves.
Using a pressure meter the test measures the change in volume of the concrete sample under a known pressure. The principle is simple: the air content of freshly mixed concrete is directly proportional to the volume change under pressure. This gives a quick and accurate measurement of the air content to ensure the concrete meets the specs.
This method is applicable to concretes and mortars with dense aggregates. Not applicable to concretes with lightweight aggregates, air-cooled blast-furnace slag or aggregates with high porosity. The pressure method gives the same results as the other two methods (C138/C138M and C173/C173M) for concretes with dense aggregates so air content measurements are consistent.
Note that the air content of hardened concrete may be different from the values obtained by this method due to type of aggregate, mix design and curing conditions. So while this method gives a reliable measurement of air content in freshly mixed concrete, variations can occur in the hardened state.
The method is versatile and can be used in laboratory and field, so it’s a valuable tool in the construction industry. By giving a quick and accurate measurement of air content it ensures concrete structures are built to last and meet the high quality standards of today’s construction.
In short, this method is the test method to determine air content of freshly mixed concrete. It’s based on volume change under pressure and gives accurate and quick results to ensure the quality and durability of concrete used in construction projects.
