하이브리드 纖維 補強 高強度 콘크리트의 耐火 및 構造的 特性에 관한 研究

Abstract

Abstract

A Study on the Fire Resistance and Structural Properties of Hybrid Fibers Reinforced High Strength Concrete

By Li, Zhi Min Adviser : Prof. Kim, Jeong-Sup Department of Architectural Engineering Graduate School of Chosun University

In this experiment, in order to prevent the explosion of high strength concrete and improve the fire resistance of the concrete, we use the method of putting in the steel fiber, polypropylene fiber and hybrid fibers into high strength concrete to make not only fire resistance specimen but also bending and shear specimens. The fire resistance specimen heated for one hour when the temperature is 200℃， 400℃， 600℃， 800℃respectively to do the fire resistance, carbonization, as well as the mechanical experiment. After the analysis of the fire resistance and the structural properties of hybrid fibers reinforced high strength concrete, It could be concluded as below.

First, in all the high strength concrete which has been put in fiber, the hybrid fibers reinforced one gives excellent performance about the explosion-proof.

Second, After the fire resistance experiment, the hybrid fibers reinforced high strength concrete is better about the residual rate of the compression strength, compared with ordinary high strength concrete.

Third, the carbonization of the hybrid fibers reinforced high strength concrete increases as raising of the fire resistance temperature. When the temperature is above 600℃, the carbonization is more serious. Moreover, although the carbonization of the hybrid fibers reinforced high strength concrete increases as raising of the fire resistance temperature, but the depression of carbonization is remarkable.

Fourth, steel fiber reinforced specimen and hybrid fibers reinforced specimen express remarkable bearing capacity in crazing of early stage. So we can use the fiber to prevent crazing in the early stage. There are also some experiment specimens used for bending resistance test gave similar data about the ductility. But the ductility of the hybrid fibers reinforced experiment specimens show 4% higher than the standard specimen.

Fifth, compared with the standard experiment specimen, the bearing capacity of the without stirrup reinforced experiment specimen with steel fiber, when the crazing appeared in the early stage, increased 62.0%. But the hybrid fibers reinforce one increased 44.6%. So, putting the hybrid fibers in the without stirrup reinforced experiment specimen which will depress the crazing significantly. The largest bearing capacity of the without stirrup reinforced experiment specimen with steel fiber or hybrid fiber increased 28.5%, 19.4% respectively, compared with the standard specimen. For the ductility of experiment specimen used for the shear behavior experiment, compared with standard one, the ductility of the steel fiber reinforced specimen increased 30.7%. And the hybrid fibers reinforced one increased 29.2%. So, the without stirrup reinforced experiment specimen with steel fiber or hybrid fiber shows better ductility.