| Title |
Effect of Fluorination on Pullout Behavior of Polypropylene Fibers from Cementitious Matrix |
| Authors |
Yun Hyun-Do ; Jeon Esther ; Lee Young-Seak |
| Keywords |
Polypropylene Fiber ; Pullout Behavior ; Hydrophobicity ; Surface Treatment ; Fluorination |
| Abstract |
High performance fiber-reinforced cementitious composites(HPFRCCs) are characterized by a stress-strain response in tension that exhibits pseudo strain-hardening behavior and multiple cracking. Such behavior is contingent on three groups of variables ; fiber(type, geometry and strength), matrix(strength, toughness, modulus) and interface related parameters such as the interfacial bond strength. In this paper, the effect of embedded length on the pullout characteristics and the effect of surface treatment with fluorination on the interfacial bond between the fiber and cementitious matrix were studied. Polypropylene fibers have a weak bond with cementitious matrix because of hydrophobicity of fibers, which does not allow for sufficient friction to develop between the two. Thus, a new method(fluorination) to improve the frictional bond by means of surface treatment of fibers was also proposed. The fluorination processing, w/b ratio of the mixtures, inclination angle and embedded length influence the pullout behavior. As a result, the fluorination process improves friction bond, maximum pullout load and end slip of polypropylene fiber. |