Influence of Mineral Admixtures on Properties of Fiber Reinforced Dry-Mix Shotcrete

摘要

Both material and fiber rebound in dry-mix shotcrete are high, and the use of an appropriate mineral admixture is known to alleviate the problem. However, the exact influence of the admixture particle size, gradation and shape on the rebound and the ultimate mechanical properties of shotcrete are poorly understood. This study is divided into two parts: in the first part, the effectiveness of four mineral admixtures-fly ash, silica fume, high reactivity metakaolin (HRM) and carbon black-with varying particle size gradations and shapes was investigated from a rebound reduction point of view. In the second part, HRM and silica fume were compared on the basis of hardened mechanical properties with special emphasis on flexural toughness in the presence of fiber reinforcement.