Development of Residual Stress Measurement for Concrete Pavements through Cantilevered Beam Testing

Concrete Residual Stress;Concrete Pavements;Concrete Surface Strain Gages;Residual Stress

Marks, David G. ; Lange, David A. ; Lange ; David A.

关键词: Concrete Residual Stress;    Concrete Pavements;    Concrete Surface Strain Gages;    Residual Stress;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/14663/Marks_David.pdf?sequence=2&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Knowledge of residual stresses is important in understanding and predicting a concrete pavement’s performance. However, there is not a standard test for residual stresses in pavements. Prior pavement research was inspired by the hole-drilling straingage method used in metals. This method involves drilling a small hole into the specimen and measuring the resulting stress relaxation near the hole with strain gages. The strain change is then used to calculate the residual stresses in the metal. The pavement research at the Federal Aviation Administration’s National Airport Pavement Test Facility showed the promise of using core rings to create a similar stress relaxation in cantilevered concrete beams. The cantilevered beams were used to create a known and moderately-uniform stress state in the specimens. Testing at the University of Illinois continued the use of core rings and cantilevered beams and also introduced a method using notches. Strain gages on each beam measured the strain relaxation due to a core ring, one notch, or many notches. Strain relaxation was clearly seen in the core ring and notch beam tests, and this relaxation was most pronounced with the notch tests. Sawing a notch on both sides of a strain gage was able to relax all of the strain induced by the cantilever loading, making the residual stress calculation quite simple. A two-dimensional finite element analysis was used to parallel the testing and to learn more about the stress distributions through notched cantilevered beams.