Experimental study on the effect of macro and microfibers on the mechanical properties of reactive powder concrete

Abstract

Due to the outstanding mechanical properties of the reactive powder concrete (RPC), it has attracted a great deal of attention. In which, incorporating fibers can improve its behavior and properties. The main objectives of this study were to consider different mixing methods and the effect of fiber content and type on the mechanical properties of RPC. The best mix proportion was selected for the final tests among 13 initial mix designs based on the 7‐day compressive strength and flow value of the fresh concrete. Different macro and microfibers (including steel, polyvinyl alcohol, glass, carbon, and basalt fibers) with volume fractions of 0.5% and 1.5% were added to the final RPC mix by two different mixing methods, and mechanical properties such as compressive, tensile, and flexural strengths and energy absorption capability were investigated. Based on the results of experiments, the addition of 1.5% hybrid (macro and micro) steel fibers had the most positive effect on increasing the mechanical properties of RPC compared to other fibers. The hybrid fibers increased the compressive, tensile, and flexural strengths and flexural toughness of the specimens by 42.5%, 26.9%, 87.6%, and 396%, respectively. According to the results, the addition of 0.5% fibers to RPC did not significantly enhance the mechanical properties of the concrete.

Influence of Anticorrosive Surface Treatment of Steel Reinforcement Fibers on the Properties of Ultra-High Performance Cement Composite

“…The values of compressive strength for composites with brass plated fibers, composites with fibers treated in HCl, and composites with fibers treated in NH 3 /H 2 O 2 are almost the same at every age. However, this indicates that the grooves in the fibers do not contribute very much to compressive strength, although the addition of fibers alone can significantly increase the compressive strength of UHPC [ 6 ].…”

“…Ductility and high flexural strength can be achieved by blending steel fibers into the UHPC [ 2 , 3 ]. Fibers of varying sizes can be used [ 4 , 5 , 6 , 7 ]. Fiber composites can be used in applications such as impact protection [ 8 ].…”

Dynamic fracture toughness of ultra‐high‐performance fiber‐reinforced concrete under impact tensile loading

“…Ultra‐high‐performance fiber‐reinforced concrete (UHPFRC) is a new class of cement‐based materials which exhibits not only very high compressive strength (more than 150 MPa) but also high tensile strength, ductility, and energy absorption capacity owing to the unique strain hardening behavior 1–4 . The superior performances at the static level have attracted the interest of many researchers to discover the impact resistance of UHPFRC.…”

Analysis of actual confinement provided by high‐strength steel spirals in reactive powder concrete of anchorage zones

“…flexural strengths, and superior durability, which can be perfectly combined with modern prestressed technology. [1][2][3][4] The application of RPC has become a development tendency, which makes the structure effectively reduce the section size under the same dominant compression stress states. 5 However, the problem of bearing concentrated prestressing force is more sensitive owing to the reduction in the section.…”

“…Reactive powder concrete (RPC) is a cement‐based material with ultra‐high compressive, tensile, and flexural strengths, and superior durability, which can be perfectly combined with modern prestressed technology 1–4 . The application of RPC has become a development tendency, which makes the structure effectively reduce the section size under the same dominant compression stress states 5 .…”