INVESTIGATION OF THE EFFECT OF STEEL FIBERS ON FAILURE EXTENSION OF RECYCLED AGGREGATE CONCRETE BEAMS WITH LAP-SPLICED BARS

In this research, the effect of adding 0\% and 2\% volumetric percents of steel fibers in beams containing three patches (43 cm, 34 cm, and 26 cm in length) and recycled aggregate 0 and 100\% on the cracking and expansion path. The cracks were examined under static loading. The purpose of this study is to reduce the minimum crack width for adding steel fibers to reinforced concrete beams made of recycled aggregates and tensile reinforcement patches. Hence, twelve specimens of the beam were made at 150, 200, 1500 mm lengths with a length of different tensile adherence rates and different percentages of steel and recycled aggregates. The experiments were performed as a quadrilateral bend. In experiments, the load-displacement curve in the middle of the span of the specimens, the trajectory expansion along the beam and at the maximum flexural anchor, the width of cracking, and the effect of adding steel fibers on the compression and elongation of the specimens were indirectly investigated. In addition, the results were compared with those presented in the ACI, CSA, NS, CEB FIP, and EuroCode2 regulations. The results of the experiments showed that the addition of steel fibers reduced the slip of the tensile reinforcement in the patched area and decreased the crack-cracking width. Also, with addition of steel fibers in beams made of 2\% recycled aggregate, the patch length can be reduced by 40\%.