Title: New Method and Apparatus for Testing Air Content of Fresh Concrete In Situ

Author(s): K. W. Nasser and R. Beaton

Publication: Journal Proceedings

Volume: 77

Issue: 6

Appears on pages(s): 472-476

Keywords: air-entrained concretes; air entrainment; air meters; fresh concretes; measuring instruments; quality control; workability.

DOI: 10.14359/7022

Date: 11/1/1980

Abstract:
This paper describes a new apparatus to measure the air content of fresh concrete in situ. The apparatus is basically a hollow tube which is open at one end and contains an electric heater at its center. The tube is pushed down into the concrete and the heater turned on for about 30 sec. The rise in temperature expands the entrained air which, in turn, raises the pressure in the confined space. The air content of the fresh concrete seems to be a direct function of the rise in pressure.