Fire Response And Fire Resistance Design Of HPC Shear Walls

In this paper the formulas of thermal conductivity and specific heat of high-performance concrete (HPC) were suggested according to the Campbell-Allen and Thorne's calculation model and Harmathy' calculation model. The relationships between thermal parameters and elevated temperatures for concrete and steel bars were summarized and compared based on the literature review from home and abroad.Three HPC shear walls with sustaining vertical loads were tested under fire. Based on the study of the fire responses (including temperature field and deformation), it can be found that PPF (polypropylene fiber) is effective in reducing the out-plan deflection of the shear wall.The fire response of HPC shear walls was investigated by the finite element program ANSYS. It is proved that the values of thermal parameters (including calcareous aggregate of normal concrete (NC), siliceous aggregate of NC, calcareous aggregate of HPC, siliceous aggregate of HPC) have only nominal influence to the temperature field distribution. Whereas speed of temperature's elevation has intensive effect on the gradient of temperature, the higher the bigger.The post-fire ultimate load of HPC shear walls was also calculated by using the finite element program ANSYS. The ultimate load of shear wall is reduced with the increase of the exposed temperature.Taking the two step model to consider concrete compressive strength at elevated temperatures, the equivalent area of concrete section was reduced. The formula calculated the ultimate bearing capacity of HPC shear wall was established.