Method for determining the proportion of finely divided powder in shotcrete, method for dividing and mixing the shotcrete obtained by this decision method and method for determining the proportion of thickener added to shotcrete

摘要

PPROBLEM TO BE SOLVED: To determine the compounding-addition ratio of fine powder or a thickener without carrying out a spray test in each construction field or minimizing, to thereby reduce costs. PSOLUTION: Shotcrete with a rebound reduced is produced by incorporating cement blended in a prescribed ratio, water, a fine aggregate, and coarse aggregate and blending/kneading fine limestone powder. With regard to the blending of mortar excluding the coarse aggregate of the shotcrete, a plurality of kinds of mortar are produced by replacing part of the fine aggregate with the fine powder, changing the content of the fine powder in turn, blending, and kneading. A fluidity test and a viscosity test concerning a plurality of kinds of the mortar are carried out, curves indicating the characteristics of the fluidity and the viscosity is obtained, and the inflection points P1 and P2 of the fluidity and the viscosity are detected. A compounding amount in the mortar is determined by the compounding ratio of the fine powder on the vicinity of the inflection point P1 or P2 of the fluidity or the viscosity. PCOPYRIGHT: (C)2009,JPO&INPIT