| Popis: |
Modern urbanization has contributed to an increase in the number of vehicles, resulting in lots of tires ending up as waste every day. It is estimated that almost 1,000 million tires reach the end of their useful life every year, with more than half of them being disposed of without being treated. One approach for making good use of discarded tire rubber is to incorporate it into cement-based materials as natural aggregate substitutes. In this work, scrap tire rubber was used as a partial replacement for coarse aggregates in normal cement concrete in the form of crumb rubber. Three different sizes of crumb tires were used in this experiment - 25.4mm (1 in) x 5mm (0.2in) x 5 mm (0.2in), 50.8 mm (2 in) x 5mm (0.2in) x 5mm (0.2in) and 76.2 mm (3 in) x 5mm (0.2in) x 5 mm (0.2in). The mix design consists of 15% of coarse aggregate content replaced by the crumb rubbers in a mix ratio of 1: 1/2: 31/2: 2: 0.001 by weight, corresponding to cement: water: gravel: sand: Sika® AIR content. Tests were conducted to determine the compressive, tensile, modulus, and air content of the concrete samples. From the test results, it could be concluded that the rubberized concrete produced higher toughness, delayed crack opening width, and ductile failure even though it had lower compressive and tensile strength than the control mix. The geometry and stiffness of the fibers had an influence on the strength of the modified concrete and the increasing aspect ratio of the crumb rubber fibers improved the post-cracking behavior of the concrete matrix. |
