This research focuses on testing reinforced concrete beams with steel layouts designed using topology optimization. With an initial truss layout, the computer can modify the sizes of tension-only truss elements representing steel within a matrix of compression-only continuum elements representing concrete.
A hammerhead pier load case is selected with 4 point loads on the top, and a simplified vertical support along the bottom.
Three different reinforcement patterns are tested. A complex and simplified optimized layout are used, as well as a control example designed by hand. All layouts have the same volume of steel.
For these small-scale prototype tests, the steel reinforcing cages are cut from plate steel using a waterjet cutting machine. This allows for high precision of steel sizing and placement. At full scale, standard rebar would be bent to achieve the designed layout.
The steel is placed into poured concrete for testing.
The two samples of each beam were tested for strength and stiffness. Experiments found that stiffness of both optimized structures increased by roughly 25% compared to the control design, while strength increased by about 30%.
These were exciting and promising results, and inform the next phase of research we are conducting on optimized reinforced concrete structures.