Abstract
For saving of capping labor in compressive strength tests of concrete, unbonded capping systems using rubber pads and steel retaining caps have been standardized by ASTM C 1231 and AS 1012.9. These standards, however, do not sufficiently specify requirements for the testing apparatus and control of rubber pad. In consideration of such circumstances, the authors conducted detailed experiments on steel retaining caps and rubber pads in order to define proper dimension of them and to specify the quality of rubber pads. Based on these experiments, this paper proposes a new rubber pad control method and describes a reasonable unbonded capping system using the proposed method.
