Date of this Version
Sondag, Tyler. Designing an Experimental Setup for Testing Concrete to Steel Bond Transfer with and without Flexure. University of Nebraska-Lincoln. 2018.
The purpose of this thesis is to present an experiment design to investigate the steel-concrete interaction exhibited in steel pile jackets. Concrete jackets are a common fix for corroding piles in Nebraska, to restore capacity and prevent further deterioration in the presence of the state’s soil. The experiment design is developed to complement previous research performed at the University of Nebraska-Lincoln. This thesis will cover a series of four tests that are intended to strategically isolate key mechanical behavior to allow for the effects induced by flexure to be distinguished from the effects present without flexure. These tests are strategically designed to improve understanding of how flexure produces enhanced composite effectiveness of bond that is expected when a moment acts in combination with an axial load. Therefore, it is expected that composite effectiveness will be increased (greater load transfer between steel and concrete) as a result of friction induced by steel flexure reacting against the surrounding concrete. Test 1 is designed to quantify the shear transfer available, on an area basis, from chemical cohesion between steel and concrete. Test 2 is designed to investigate end bearing strength, particularly in comparison to code-based design expectations. Test 3 is designed to be a combination of Test 1 and Test 2, and will provide data for combined end bearing and the bond, resulting from chemical cohesion when a pile is subjected to axial load only. Test 3 will provide a reference for Test 4, which includes a flexure loading component. Test 4 will be similar to Test 3, but Test 4 will include moment induced by eccentricity between the centroidal axis of the test specimen and the line of action of applied external axial loads. Experiments performed using the configurations described in this thesis will yield data that will help to further the understanding of the composite effectiveness that occurs when flexure is induced in a pile retrofit scenario, and therefore an improved understanding of the capacity available from this type of retrofit.