Applicability of Crush Stone Powder and Recycled Concrete Powder to High-Fluidity Concrete
Takayuki FUMOTO and Masaru YAMADA
Abstract:Crushed stone powder is produced when crushed stone are produced. And recycled concrete powder is produced with producing of recycled aggregate. Those powders are hardly reused. High fluidity concrete needs appropriate amounts of power for preventing concrete segregation. So, the purpose of this study is to investigate the applicability of the crushed stone powder and the recycled concrete powder to high fluidity concrete and the influence of powder quality. At first, evaluation index for concrete segregation was examined for evaluating effects of the powder to flesh concrete. At the result, the ratio between coarse aggregate weight in lower concrete of cylindrical vessel and one in upper after tamping by steel rod more accurately expressed the segregation in contracting. Then, it was found that plastic viscosity of mortar and volumetric percentage of coarse aggregate in concrete mainly influence the index. Next, it was investigated the influence of the 15 powders on properties of high fluidity mortar. The mortar segregation is expressed by plastic viscosity of the mortar because of the previous result. At the result, the surface of the crushed stone powder and the recycled concrete powder is rougher than other powder. Thus, the mortar flow with those powders is decreasing with increasing the plastic viscosity when quantity of the using powder is increasing. Key Words:Segregation, Crush stone powder, Recycled concrete powder, High-fluidity concrete, Specific surface area