METHOD AND DEVICE FOR MEASURING QUANTITY OF AIR IN CONCRETE

PURPOSE:To measure a minute quantity of accompanied air easily, quickly, and accurately by charging a dry concrete into a vessel of 7l volume after about 2l water is charged there and saturating the concrete in the vessel with water and using a pressure gauge with a scale subjecting to correcting calculation. CONSTITUTION:About 2l water is charged into a vessel 1 of 7l volume, and 10kg a sample of dry concrete where an AE agent to be measured is mixed is charged into the vessel 1, and a side face 1a of the vessel is tapped to substitute spaces in the concrete with water completely. After water is supplied up to an upper face 10 of the vessel 1, bubbles floating on the upper face 10 are removed, and an upper cover 2 is set and fastened to the vessel 1 by a screw, and thus, the vessel is closed. After air in spaces 5 is discharged completely, the pressure of an air chamber 11 is raised until a needle indicates an initial pressure normal line 12. Next, air in the air chamber 11 is released to read a measure indicated by a needle 7a of a pressure gauge 7. This indicated measure is subjected to correcting calculation preliminarily, and the numerical value of the indicated measure indicates the quantity of air mixed in the concrete.