MEASURING METHOD FOR WATER/CEMENT RATIO OF CONCRETE BEFORE HARDENING

PURPOSE:To quickly measure a water/cement ratio with high accuracy, by using jointly a unit water quantity measurement and a viscous resistance value measurement. CONSTITUTION:A vibration terminal 2 is inserted into concrete 1 before hardening, a prescribed vibration is given by an exciting part 3, a vibration attenuation value is detected by a pickup 4, and a result is displayed on an indicator. Simultaneously, an iodine ion is thrown as an indication ion into concrete in a mixer 7 of a concrete mixer car 6, stirred, and thereafter, sampling is executed, an ion concentration is measured, and from a dilution value, the unit water quantity of concrete is calculated. Subsequently, a viscous resistance value of concrete obtained by a vibration test is corrected, based on the calculated unit water quantity as a reference, the quantity of cement in the concrete is derived, and a water/cement ratio is calculated.