METHOD OF MEASURING MOISTURE CONTENT IN FRESH CONCRETE, AND MOISTURE CONTENT MEASURING APPARATUS USED FOR SAME

摘要

PPROBLEM TO BE SOLVED: To provide a moisture content measuring method for easily measuring the unit quantity of water in a fresh concrete as a critical quality control object, for obtaining a reliable measured result, and for preventing the fresh concrete from being installed inappropriately. PSOLUTION: A plurality of the tested fresh concretes having different composition ratios are created, prior to manufacture (7) of the fresh concrete (1). A reference concrete (2) and the reference unit quantity of water (3) are determined, while a plurality of the tested concrete are created. The tested fresh concrete is picked up and placed in a vessel (4); correction coefficients for a calibration equation is found (6) by using attenuation ratios of the gamma ray and the neutron radiations irradiated from the outside of the vessel. A sample of the fresh concrete is irradiated with the gamma ray and the neutron radiation in the field, before installation; the calibration equation is applied to the attenuation ratios; and unit quantity of water calculated in the sample is considered as the unit quantity of water in the fresh concrete. PCOPYRIGHT: (C)2005,JPO&NCIPI