Synthetic Study on Self-Placeable Concrete

点击翻译按钮获取中文摘要

Experimental and analytical studies were carried out in order to develop concrete for self- placeable concrete and to establish the manufacturing and construction system for the concrete. Through this research, following results were obtained.1.Development of cementitious materialTesting methods of the qualities of cementitious material were proposed. Using these methods,many kinds of powder material were evaluated. It was concluded that the moderate heat cement is suitable as the standard powder material for self-placeable concrete. On the other hand,it was pointed out that the deformability of concrete depends on the combination of the cement and the super plasticizer.2.Development of material design systemMaterial design system for concrete was established. The system is composed of the mix design system and the durability check system.3.Development of manufacturing systemControl system of the filling capacity of concrete by using two-step mixing was established based on the investigation of the mechanism of mixing. In the upper mixer,surface water of sand is adjusted using the torque of mixer. In the lower mixser, slump flow and funnel passing time are controlled. Filling capacity of concrete are successfully controlled by this system.4.Development of construction systemIt was clarified that the construction system can be rationalized by the improvement of construction method which includes the application of self-placeable concrete and the decision of structural type. Confirmation method of filling of concrete to the structure using infrared rays was developed. Appraisal system of new construction technology,which includes self-placeable concrete,was established from the viewpoint of constructability,durability(quality) of structure and economizability.