PURPOSES : In this paper, the flow of cement paste layers that were contoured at different times were simulated by computational fluid dynamics in 2D axisymmetric conditions to evaluate the effect of yield stress on the flow of cement paste layers.
METHODS: In the 2D domain, the cylindrical-shaped bottom layer was placed on even ground and allowed to flow by gravitational force for only 25 s. The exact same shape of cement paste, the top layer, was placed on top of the bottom layer, and both layers were allowed to flow for an additional 25 s. The shape and pressure of both layers were evaluated.
RESULTS: The relationship between the yield stress and diameter of the layer was clearly observed from the numerical simulation results. It was also observed that the interface between the top and bottom layers was affected by the yield stress and fluidity of materials. The total pressure underneath the bottom layer can be a good indicator of whether the material is still flowing or not.
CONCLUSIONS: The Navier-Stokes equation with Bingham model is an excellent model to simulate the flow of contoured layers, which can be used to explain the flow of materials in various areas such as wet-on-wet pavement construction, structural member precasting, and 3D printing construction.

ABSTRACT
 1. 연구배경 및 목적
 2. 유동성 재료의 동적 거동
  2.1. 기본가정 및 물성 조건
  2.2. 전산유체역학을 활용한 유동 예측조건
  2.3. 비적층 조건에서의 재료의 유동
  2.4. 적층조건에서의 재료의 유동
 3. 결론 및 향후 연구 내용
  3.1. 결론 및 요약
  3.2. 향후 연구내용
 REFERENCES

• 윤태영(한국건설기술연구원 수석연구원) | Yun Taeyoung 교신저자