Full-scale load tests of Pearl-Chain arches

Abstract

Specially designed, prefabricated , lightweight, concrete deck elements (SL-Decks) can be post tensioned together into an arch shape (Pearl-Chain arch). Individual arches can then be erected adjacent to one another in order to form a bridge span. Two Pearl-Chain arches, each with a span of 13 m and a rise of 1 m, were erected onto a prepared test foundation. The aches were tested with load control by applying a gravity load to the ¼ point of the bridge span. Two tests were completed on the same specimen in order to determine the behavior of an arch bridge formed with SL-Decks. The first test investigated the system's elastic response (maximum load of 648 kN), and the second test demonstrated its collapse mechanism and ultimate capacity (maximum load of 970 kN). Analytical calculations showed that the loaded 3/8 point of the span and the non-loaded ¼ points of the span were critical locations for the structure. Failure initiated at the 3/8 and 5/8 points. Plastic hinges were observed at a load near the fracture load, and different warning signs were seen at 84% to 94% of the fracture load. The ultimate, experimental load capacity was 14 % higher than the calculated result (load of 849 kN), and the difference was mainly due to the assumed static system used in the calculations. Measurements performed in Test 1 showed that the SL-Decks, which contained lightweight aggregate concrete blocks (LAC blocks) in the bottom of their cross sections, may have benefited from multiaxial compression effects. Furthermore, the pair of test arches were connected with so called Hammerhead joints in order to transfer forces from one arch to the other. The displacement data suggested that when a load was applied to a single arch, some proportion of that load was transferred to the adjacent arch.

Design for Disassembly of Concrete Slabs with Mortar Joints

“…The case buildings had a total floor area of 106,000 m 2 and had typical layouts and no odd shapes. A large variety of HCSs was used in the buildings with different configurations of pre-tensioning strands, different lengths and widths, and adaptations (e.g., hammerhead shear joints or holes [43]). Figure 5 highlights some of the most important variations.…”

Re:crete – a Footbridge Made of Reused Concrete Blocks

“…Other examples are beam bridges made of granite segments assembled by external post-tensioning [20]. Concrete is also used for such construction as for example in the so-called "pearl-chain" arch bridges [21,22].…”

The application of modern methods for bridge diagnostics and load testing

“…The deflections may be measured using pre-assembled speckle pattern targets, firmly attached to the structure, or using the natural textures of the existing structures if they exhibit suitable properties [6], [7]. The DIC measurement is also suitable for field diagnostics, allowing to measure full-fields of strains, displacements and rotations, which may be used for crack detection, stress concentration investigation or other assessment of specific details behaviour [8], [9]. Moreover, DIC obtained data are continuous.…”