| 摘要 |
PROBLEM TO BE SOLVED: To provide an evaluation method, for the initial hardening property of shotcrete, in which a change in the strength of the spraying concrete can be evaluated continuously or intermittently, simply and precisely without relying on the experience or the intuition of an operator at a construction site. SOLUTION: The elastic wave velocity (and the strength) of a sample which is taken out from a form in advance, which is to be solidified and which is being hardened are measured. Data on the elastic wave velocity of the sample which is changed with the passage of time is recorded continuously or at desired intervals. On the basis of the data on the elastic wave velocity, shotcrete which is used at every construction site is sprayed on a form. A sample 1 is manufactured. Then, the elastic wave velocity (and the strength) of the sample 1 which is to be solidified in the form and which is being hardened are measured. The elastic-wave velocity (and the strength) are compared with the data on the elastic wave velocity. A hardening state after the spraying execution of the shotcrete at every construction site is estimated. The progress state of a further construction operation after the shotcrete is sprayed is judged. |
