| Scope of study. This study is part of a research project to establish the effectiveness of shear transfer mechanism by aggregate interlock at contraction joints in highway pavement made with high-strength concrete. For this research, it was necessary to develop equipment to apply a known magnitude of fully reversed cyclic shear force across an open crack in a pavement joint specimen. In addition, suitable instrumentation must be provided to monitor the deterioration of joint resulting from loading.;Findings and conclusions. A test system was developed to test pavement joint specimens. The system consists of four components: a load application system, a restraining and crack width adjusting system, a crack forming facility, and a data acquisition system. Speciments were designed to represent an element of pavement joints. Results from performance tests showed that the system functioned satisfactorily and reliably. Because the initial restraint system involved the use of rod end bearing which had several thousandth of an inch of 'play', difficulties in setting of crack width were found. In order for the restraint system to function for constant crack width tests, modifications of these linkage hinges were made by using flexure assemblies in place of the rod ends. Calibration tests showed that the modified system had no sloppiness and has the total restraint stiffness of 653 kip/in. which is approximately 4 times greater than the initial system. |
