Time-varying Law of Mechanical Properties of Scrap Tire Rubber Pads Under Thermal Aging

In order to study the mechanical properties of scrap tire rubber pads (STP) under different aging time, a 6-layer STP of 180 mm×180 mm was selected as the test object. The accelerated aging tests of STP specimens were carried out for 113 h, 223 h, 336 h, and 449 h, respectively, at a constant temperature of 100℃. The mechanical properties of STP after aging were tested and studied, such as compression properties, shear properties, shear strain correlation and so on. The changes of compressive elastic modulus, vertical stiffness, post-yield stiffness, yield force, and horizontal equivalent stiffness of STP with aging time were analyzed. This paper proposed a test method of compressive elastic modulus which was suitable for STP and could shorten the test time. Based on the results of the improved test method, the compressive elastic modulus of STP before and after aging test was compared and verified by vertical stiffness calculation theory. The test results showed that the improved compressive elastic modulus test method suitable for STP saved time and the result was accurate. When the STP was aged for 223 h (50 a at room temperature), the compressive elastic modulus and vertical stiffness were the highest, after 223 h, it showed a slight downward trend, and then it was basically flat. At the same time, the Arrhenius equation was used to fit the time-varying regularity formula of the STP compression perfor-mance index under different aging time. When the shear strain was in the range of 25%-100%, the horizontal equivalent stiffness and the post-yield stiffness of STP decrease with the increase of shear strain under different aging time. Its yield force increases as the shear strain increases. © 2020, Materials Review Magazine. All right reserved.