In this study, viscosity was minimized for production of viscosity-agent type high fluidity concrete with normal strength, and segregation resistance was maximized with viscosity agent and use of superplasticizer. Their applicability and physical property were examined.

This research deals with the anti-washout underwater concrete applied for cast-in-place piles constructed by RCD(Reverse Circulation Drill). The anti-washout underwater concrete exhibits a compressive strength larger than 35 MPa and a slump flow of 600 mm. It is also a high fluidity anti-washout underwater concrete with an intended mass of suspended solid smaller than 150mg/ℓ. And then, we evaluated the quality performances and the fludity characteristic of the developed high fludity anti-washout underwater concrete in this study.