| dc.description.abstract | Mortars generally have low characteristics and performance. Mortar technology continues to develop for better achievements. Meanwhile, there is a lot of waste or residual production materials that have not been utilized optimally, such as silica fume, rice husks, etc. In addition, in line with the increase in motor vehicle production, the number of used tires has also increased. This condition can cause environmental problems in itself. In relation to these matters, this research has utilized these waste materials, including silica fume and rice husk ash for the manufacture of Engineered Cementitious Composites (ECC) mortar, as well as the utilization of crumb rubber (CR) for the manufacture of CR- ECC. Related to the compressive strength of ECC mortar, for the purposes of the pressure test, a cylindrical specimen with a diameter of 100 mm and a height of 200 mm is used. The number of variations there are 16 pieces where each variation has 3 cylinders so that the number of test objects is 48 cylinders. Silica fume (SF) and rice husk ash (ASP/RHA) have variations of 0%, 5%, 10% and 15% by weight of cement, respectively. The ECC mix design was obtained by trial and error (trial and error in the laboratory). The compression test was carried out at the age of 1 day using a pressure testing machine with a capacity of 3000 kN. The compressive strength of the ECC mortar ranges from 19.09 to 39.03 MPa. After completing the ECC mortar pressure test, the mix proportion that produces the optimum value is then used to vary it with crumb rubber (CR), where the CR variation is 0%; 2.5%; 5%; 7.5%; 10% and 12.5% by weight of cement. Each variation also uses 3 cylinders with a diameter of 100 mm and a height of 200 mm. The compressive strength of CR-ECC at 1 day of age ranged from 21.63 to 36.48 MPa. Based on the results of the CR-ECC compression test, 1 representative mix proportion was taken, with the consideration that the compressive strength is greater than 21 MPa, and the use of sufficient CR content. The workability of the ECC and CR-ECC mortars is quite good and complies with the EFNARC standards. Mortar ECC and CR-ECC will then be used for grouting beams. The final objective of this research is to study the behavior of beams in resisting bending loads, both for normal beams and for beams grouted with ECC and CR-ECC mortar. The test object is 600 mm long, 100 mm wide and 100 mm high. Each type of beam has 3 specimens. The first type of beam is normal beam, which uses normal concrete with a compressive strength value of 29.26 MPa at 28 days. The first type of beam is also called the control beam. While the second type of beam is a normal beam with 3 holes at the bottom along the beam, where the hole diameter is 12.7 mm and the distance between the holes is 25 mm. When the normal concrete reaches the age of 27 days, the three holes are grouted with ECC mortar. Furthermore, the 3rd type of beam is basically the same as the 2nd type of beam. But on the 3rd type beam, all three holes were grouted with CR-ECC. Flexure testing is carried out when normal concrete is 28 days old. Each beam has a simple support. The 1 point bending load is divided by the spandel beam so that it becomes 2 point loads. Flexure testing is carried out until the test object collapses. Based on the results of the bending test, it was found that the control beam had a maximum load capacity of 908.672 N, and an average collapse deflection of 0.950 mm. While the second type of beam has a maximum load capacity of 2707.053 N, and an average collapse deflection of 12.722 mm. Then the 3rd type of beam has a maximum load capacity of 2100 N, and an average collapse deflection of 17.929 mm. So it can be seen that the beams that have been grouted with ECC or CR-ECC mortar show better flexural capacity values (maximum load and collapse deflection) compared to the control beams. Beams that were grouted with ECC mortar showed a maximum load capacity of 2.9 times greater and a greater deflection capacity of 13.39 times than the control beams. Meanwhile, beams grouted with CR-ECC showed 2.31 times greater maximum load capacity and 18.87 times greater collapse deflection capacity than control beams. This fact proves that ECC and CR-ECC mortar can be used as alternative grouting materials in field applications. | en_US |
