30∼150㎫급 콘크리트에서 채취한 모르타르의 레올로지 특성과 콘크리트의 유동특성과의 상관성에 관한 실험적 연구

Abstract

The high strength concrete in general has widely been used in many construction fields since mineral admixtures like silica fume and the high-range water reducing agents were radically developed in the 1990s. As high strength concrete usually contained many different materials, it is difficult that workability of fresh concrete was quantitatively established by existing test methods like slump and slump flow which people had used in many construction sites. Therefore, many researchers have suggested that workability was measured by using parameter of rheology in fresh concrete. However, established methods used cement paste unfortunately have some problems which cement paste rheology is measured under different conditions which are experienced by cement paste in concrete. In this paper, parameter of rheology was measured by gained mortar by passing sieve on fresh concrete after finishing mixing. Also, the rheological results of gained mortar by passing sieve were compared with existing test methods like slump, slump flow and O-lot. The investigated results are that yield stress of gained mortar by passing sieve was related to slump flow and plastic viscosity was directly concerned in reached time of to 500㎜ slump flow and O-lot flow time.