Abstract
The hybrid effect of twisted steel (T) fibers with an aspect ratio of 100 and polyethylene (PE) fibers with four different aspect ratios of 400, 600, 900, and 1200 on the mechanical performance of ultra-high-performance cementitious composite (UHPCC) was investigated. This involved a total of 17 different sample types at an identical fiber volume fraction of 2% being made and subjected to compressive and tensile loads. Samples were made by replacing 0.5%, 1.0%, 1.5%, and 2.0% of T fibers with four different types of PE fibers. In addition, the pullout behaviors of fibers at cracked sections and the cracking behaviors of specimens were evaluated in order to determine the effect of the pullout mechanism of each fiber on the overall tensile performance. Test results indicate that the compressive strength decreased in proportion to the amount of PE fibers, regardless of their aspect ratio. The fiber hybridization had a great synergetic effect, successfully improving the tensile strength and strain capacity of UHPCCs; this effect was dependent on the aspect ratio of the PE fibers. Finally, the cracking behaviors were determined to be more related to the fiber type and pullout mechanisms than the tensile strength or strain capacity of UHPCCs.
Highlights
The two most widely used strain-hardening high-performance cementitious composites were the ultra-high-performance cementitious composites (UHPCCs) and engineered cementitious composites (ECCs)
The compressive types on the compressive strength are generally less than the tensile properties of UHPCCs
Based on the test results of this study, it was found that the PE fibers noticeably fiber types on the compressive strength are generally less than the tensile properties of UHPCCs [6,21]
Summary
The two most widely used strain-hardening high-performance cementitious composites were the ultra-high-performance cementitious composites (UHPCCs) and engineered cementitious composites (ECCs). A significant amount of research has already been conducted in an attempt to enhance the pullout resistance of steel fibers and the tensile or flexural performance of UHPCCs. Since the mid-2000s, the effect of geometric deformation of steel fibers has been investigated as an efficient way to improve the mechanical properties of UHPCCs [6,7,8,9]. In order to overcome the limitations of UHPCCs and ECCs, a fiber-hybridizing technique was adopted to obtain high-strength and high-ductility properties in cementitious composites. T fibers has been limited due to the formation of splitting cracks in the cement matrix surrounding the T fibers; these are caused by the excellent bond strength and untwisting moment of T fibers For this reason, our study focused on mitigating the premature deterioration of the matrix caused by the pulling-out process of T fibers. Micrography was conducted at the localized crack surfaces to rationally analyze the tensile test results based on the pullout mechanism of each fiber
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
