Key Technology Of Internal GHPC Casting In Complex Steel Reinforced Concrete Composite Structures

With the development of high-rise and long-span buildings in the past decade, complex steel reinforced concrete (CSRC) composite structure has been used and develops rapidly in practical engineering. The composite structure members are very important to the safety of the construction and have certain complexity in its internal concrete casting. Without enough research, necessary concern and effective manage measure, the internal concrete cast in structure members may be in compact, which leads the defects between the concrete and complex steel. Thus, the bearing capacity of structure decreases and the function and safety are affected.Based on the research on the properties of green high performance concrete and its application in practical CSRC project, theoretical analysis and experimental study on proportioning, casting, testing and evaluation was carried out under the concept of holism, instead of resolving it into materials, construction and quality management separately. The key technology of complex composite structure with internal casting green high performance concrete was proposed in this Thesis. The study aims to provide theoretical and technical supports for similar practical application, which has certain social and economic benefits.The major work in the thesis includes:1) Analysis of the casting characteristic and environment condition and experimental study on proportion design and concrete curing from inside.2) Analysis of the difficulty in construction of CSRC composite structure and experimental study on pumping lift-up construction technology.3) Testing and evaluation on the defects in CSRC composite structure, and further study on testing method based on piezoelectric intelligent material.4) Conclusion of quality management of CSRC composite structures and control measures from four SAPects, and5) Illustration of key technologies in three practical CSRC composite structure projects.The results show that certain measures should be taken to insure the quality of structure members and to prevent the defects. Since the importance of composite structure member and its complexity in concrete casting, the following measures are suggested:The proportion design should considering more on workability rather than durability of the concrete itself and add SAP for internal curing. The pumping lift-up construction technology, Testing and evaluation method based on piezoelectric intelligent material, and quality management and control measures from four SAPects are recommended.