Tensile behavior of fiber reinforced cement mortar using wastes of electrical connections wires and galvanized binding wires

Abstract

This study aims to improve the tensile strength of cement mortar using recycled short copper fibers (CE) from wastes of electrical connection wires and long steel fibers from galvanized binding wires (GB). Therefore, a series of direct tensile tests were performed to investigate the tensile behavior of mono and hybrid fiber reinforced cement mortar in addition to compressive and flexural strengths properties. Different hybrid ratios (CE: GB = 0: 100, 100: 0, 50: 50, 30: 70, and 70: 30) % and fiber volume contents (0.5, 0.75, 1, 1.5 and 2)% were studied to investigate their effects on the tensile behavior. The test results revealed the following: (i) the (GB) fibers improve the flexural strength in all volume fraction ratio when compared with (CE) fibers and the optimum ratio was 1%. While for mixtures with hybrid fibers, the (30%CE to 70%GB) combination gives the highest percentage increase in flexural strength at 1.5% volume content when compared with all other mixtures; (ii) for both types (GB) and (CE) fibers, the direct tensile strength increases with the increase in volume fraction ratio till 1.5%. While, for hybrid fibers, the direct tensile strength increases with the increase in fibers ratio for all volume contents and for all combinations; (iii) the largest increase in direct tensile strength is observed at 1.5% volume content of (GB) fibers and give the highest values in comparison with (CE) fibers and hybrid fibers in all mixes; (iv) the brittleness ratio ranges between (4%-8%), (5%-10%) and (4.5%-9.5%) for (CE), (GB) and hybrid fibers cement mortar, respectively. And the direct tensile strength is nearly about 55% of flexural tensile strength as average for all fibrous cement mortar.