Establishment of Mix Design Method and Work Method of Mortar for Structures

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In this study, the following was investigated in order to prepare the mix design method and the work method of the mortar for structures (the mortar, of which aggregate volume is increased by using fine aggregate with special grading to control drying shrinkage to the same level as that of concrete, for applying to structures).1. Segregation mechanism of aggregate: The process of segregation of aggregate subjected to vibrating compaction was visualized using the simulated mortar.2. Design method of grading of fine aggregate: The relationship between the grading of aggregate and the solid content was investigated. And the prediction method of the solid content of aggregate composed of two or three grain size was advanced.3. Effect of air content: The effect of air content of the mortar for structures on fresh properties was investigated. And it was determined that the yield value of the mortar is estimated comprehensively based on the distance between aggregates in dispersion calculated ignoring air content.4. Vibrating compaction method: The rheological properties and the segregation resistance of the mortar for structures subjected to vibrating compaction were investigated. And it was confirmed that the mortar for structures can be cast with the vibrating compaction method similar to that for concrete.5. Strength characteristics and drying shrinkage: The following results for the mortar for structures were obtained: 1) Compressive strength is nearly equal to that of concrete. 2) Young's modulus can be predicted by the JASS 5 equation. 3) Drying shrinkage can be controlled to the same level as that of concrete.6. Feasibility of high-fluidization: The feasibility of high-fluidization of the mortar for structures was investigated. And it was determined that if water cement ratio is less than 42.5%, the slump flow of the mortar for structures can be fluidized to 70cm.