Experimental Study of Indonesian Low-Cost Glass Fiber Reinforced Elastomeric Isolators (GFREI)

Abstract

In this research, four specimens of elastomeric base isolators were tested. They were named as A1, A2, B1, and B2. The type A and B elastomeric isolators were made from the hyperelastic rubber with the hardness of 40 and 60, respectively, according to the durometer scale shore A. Prior to the making of elastomeric isolators, both rubber categories (40 and 60) were tested to obtain the mechanical properties of these types of hyperelastic rubbers. testing of hyperelastic rubbers and elastomeric isolators were carried out following BS EN 15129:2009 requirements. The A1 and B1 specimens were tested under vertical load. For lateral load tests, double shear tests were carried out. Specimen A1 which has been tested under vertical load previously was used to be combined with Specimen A2 and tested under lateral load. This double shear test was also conducted to Specimens B1 and B2 in which B1 has been tested earlier under vertical loading. From the results of the hyperelastic rubber tests, the elongation at the breaking of type A and B rubbers were more than 500 and 400 percent with the maximum stress of 8.8 and 6.2 MPa, respectively. While the testing results of type B elastomeric isolators showed better damping ratio than type A, the effective stiffnesses of type A elastomeric isolators were found higher than type B. From the test results; it can also be shown that higher-story buildings, which have high axial forces, might use type B elastomeric isolators which have higher hardness and damping ratio, whereas low-rise buildings with low axial forces can use type A elastomeric isolators. Thus, it can be concluded that the Indonesian rubber has a bright future and has a strong potential to be developed for use in the production of low-cost elastomeric isolators.