The Effect of Steel and Basalt Fibers on the Shear Behavior of Double-Span Fiber Reinforced Concrete Beams

Abstract

This study investigates the effects of adding different types of fibers to concrete mixes on the shear behavior of double-span fiber-reinforced concrete beams with or without shear reinforcement. As a part of the experimental study, a total of twenty-seven natural-scale double-span beams were tested. The beams, made of concrete with steel or basalt fiber, with fiber dosages of 78.5 and 5 kg/m3, were tested under shear force. The three tested series consisted of three beams with dimensions of 120 × 300 × 4150 mm, with various numbers of stirrups and contents of fiber reinforcement. During the tests, the shear capacity of the elements was determined. The values of support reactions, deflection in the middle of the span of both beam spans, deformations on the surface of the concrete member in the middle of the span in the compressive and tensile zone, and cracking (crack development and crack width) were also measured. The beams were tested using a digital image correlation (DIC) technique. Test results show that shear capacity increases in beams made of concrete with steel (1.87) or basalt fibers (1.23). Moreover, the failure mode changes from shear (brittle) to flexure-shear (less brittle). The experimental shear capacity of beams was compared with the theoretical values predicted by different design codes, i.e., fib Model Code 2010 and RILEM TC 162-TDF 2003. The results show that all the design codes underestimate the contribution of fiber-reinforced concrete beams to shear resistance and greatly overestimate the contribution of shear reinforcement.

Theoretical and Experimental Substantiation of the Efficiency of Combined-Reinforced Glass Fiber Polymer Composite Concrete Elements in Bending

“…All this is proposed for use not only in compressed elements, as in [18,19,[28][29][30][31][32][33], but, of course, in tensioned bending elements, which emphasizes the more rational operation of fiber-reinforced elements, since fiber reinforcement is primarily directed for bending and tensile loads. In this regard, our result surpasses the results of [6,9,14,17,18,27,[33][34][35][36][37][38].…”

“…Research on improving the characteristics and operation parameters of compressed [18,19,[28][29][30][31][32][33] and bending elements [6,9,14,17,18,27,[33][34][35][36][37][38] because of fiber reinforcement continues to expand and open new possibilities for their application. At the same time, researchers have studied the behavior of columns and beams made of steel fiber concrete [6,30], ultrahigh strength fiber concrete [36], glass geopolymer concrete with hybrid fibers [29], steel fibers [34,35], basalt fibers [34], hybrid epoxy resin, reinforced with flax or fiberglass [28], and steel fibers from scrap tires [31].…”

Effectiveness of Selected Strain and Displacement Measurement Techniques in Civil Engineering

“…In the case of measurements on elements made of brittle materials such as concrete, the DIC system is well suited. This system enables a very effective measurement of crack propagation, as shown, for example, in [31][32][33]. This is due to the appearance of much larger values of displacements between the pattern points.…”

Comparative Performance Analysis of Small Concrete Beams Reinforced with Steel Bars and Non-Metallic Reinforcements

“…Recently, numerous studies have explored the intricate properties of fiber-reinforced polymer (FRP)-reinforced concrete beams, as evidenced by a growing body of research [14][15][16][17]. Many of these investigations have focused on the behavior of concrete beams that are reinforced with a single type of fiber reinforcement, comparing their performance against that of conventional steel-reinforced concrete beams [16][17][18][19][20][21][22]. Conversely, other studies [23][24][25][26][27][28][29] have chosen to examine FRP bars in isolation, subjecting them to various conditions to elucidate their intrinsic properties without integration into concrete structures.…”