عنوان مقاله [English]
Considering the seismic conditions of Iran and the many damages that occur as a result, it is necessary to change the current performance of structural design to achieve better performance in the seismic system. On the other hand, environmental concerns have prompted civil engineers to identify appropriate methods of reusing construction waste. The purpose of this research is to investigate the behavior of concrete made with recycled materials as a wide foundation, which has the role of seismic isolation for low or medium height buildings. In this research, the effect of crumb rubber and recycled concrete aggregate on concrete was examined in a laboratory. The design basis of its resistance is 30 MPa. The first mixture, as a control mixture, does not contain rubber granules, Forta fibers and recycled concrete aggregate. In the other three mixtures the difference in the amount of recycled concrete aggregate is 40%, 50% and 60% instead of coarse aggregate, also the percentage of rubber granules is constant and about 15% of the total volume, and the amount of Forta fibers is about 0.5% of the total volume. Compressive strength, Flexural strength and Shear strength tests were performed on the 4 mentioned mixtures at the age of 28 days in a laboratory. The results of the compressive strength test showed that the addition of recycled concrete aggregate, rubber granules and Forta fibers has significantly reduced the compressive strength value. The results of the flexural strength test indicated that the additives cause a noticeable reduction in the flexural strength and this reduction intensifies with the change of recycled concrete aggregate percentage. The results of the shear strength test represented a considerable increase with the increase in the percentage of recycled concrete aggregate. Based on the test results, it is concluded that this type of composition material can be used as a foundation isolator, which showed a favorable shear behavior.