The Effect of Concrete Cover Thickness for Reactive Powder Concrete on the Column Resistance Against Fire

Structures made of reinforced concrete are often exposed to fire of varying intensity. If the building does not burn down, a post-fire study of the building's structural integrity is necessary before determining the building's destiny. It can forecast the remaining loading capacity of the columns after a fire by knowing the temp of the fire, the thickness of the cover of concrete, the concrete's residual strength, and the tensile strength of the embedded strengthening. Over the past few years, there has been significant progress in the construction of urban cities. This progress has led to improvements in the building process, particularly in the requirements of structural design for extremely robust building products. One important factor that has been given more attention in building design is the length of building elements. Since its exceptional strength and durability, reactive powder concrete (RPC) has gained significant attention in the field of building construction in recent times. Therefore, incorporating enhancements can greatly contribute to preserving the optimal performance of concrete in various scenarios, including fire exposure. The current study seeks to examine the variations in strength of reactive powder concrete once subjected to different burning temperatures (200, 400, and 600℃) through experimental testing. The experiment involved three sets of specimens; each set exposed to different burning temperatures for one hr. Within each set, the specimens were further split into four subgroups to observe the effects on cover of concrete at depths of 15mm and 30mm, with and without secondary strengthening. The findings gained indicate that greater burning temperatures, ranging from 200-600, lead to a decrease in the compressive, tensile, and flexural strength of reactive powder concrete. In addition, the decision for increment the cover of concrete from 15 to 30 mm has proven to be effective in enhancing the fire resistance of the concrete column.