A New Test Method for Determining the Shear Modules of Elastometric Bridge Bearings

The shear modulus of elastomeric bridge bearings has to be determined reliably for a satisfactory design. Current test methods cited by the design codes are applied to small samples and are not reflective of the full-size bearing performance. Although there are test setups to evaluate the performance of full-size bearings, they cannot be used extensively due to their cost and difficulty of construction. Due to these reasons, there is a need for a new test method that can evaluate the shear modulus of full-size elastomeric bridge bearings easily and cost effectively. This paper concentrates on the evaluation of a new proposed test method. Certain full-size bearings were tested with the new and existing test methods to find out the applicability of this new test method. Test results revealed that the new test method is capable of giving good estimates of shear modulus for laminated bearings but cannot give good estimates for plain pads. In addition, certain test parameters were investigated to standardize this new test method. It was found out that, for a standardized test, the testing time, surface and edge conditions of the bearings have to be specified.