Fire Performance Of Axially Restrained High Strength Concrete (HSC) Columns In Uneven Fire Boundary

High Strength Concrete has been increasingly used in the high-rise buildings becauseof its high strength, durability, etc. Numerous studies found that spalling always occurs athigh temperature in high strength concrete, greatly reducing the fire resistance of highstrength concrete columns. Due to the different locations in a building, the columns may besuffered by1-,2-,3-, or4-face fire exposure.At present, few experimental studies on axially restrained High Strength Concretecolumns have been done. In this paper, axially restrained HSC columns in uneven fireboundary were analysed. The main contents are as follows:1. Through the study on fire-resisting tests of3axially restrained HSC columns withdifferent fire conditions under different eccentricity ratio, the temperature field, fireresistance，deformation curve and failure process were obtained.2. The suitable thermal and mechanical properties were chosen before the simulation.The finite element software, ABAQUS, was used to study the fire performance of axiallyrestrained HSC columns including a concentrated spalling. The rationality of the modelwas verified by test data.3. The concentrated spalling time, the length and the depth of spalling wereconsidered as the factors to the temperature field, axial deformation and fire resistance ofthe HSC columns respectively under4-or3-face fire attack.4. Effect of the parameters on fire resistance of axially restrained HSC columns,exposed by standard fire curve, was analyzed. The influenced factors included load ratio,axial restraint stiffness ratio, eccentricity and section size. Based on the parametric analysis,the influenced law was summarized.