This year I am taking a module taught by Dr Saverio Spadea, about the Structural design of concrete structures. This module uses legislation and shows us how to apply them when designing structures. As part of this, we have been designed prestressed concrete beams. Beams that have steel cables in tension compressing the concrete beam prior to loading. As part of this, we got to build and test some in the laboratory.
The first step was making the beam, using a mold and steel tendons we created a t shaped mold and pre-stressed cables in the mold. Mixing concrete in the concrete laboratory we added it into the mold and left it to cure for 28 days.
28 days later..
In our next laboratory session, we were based in the structural lab. Using a hydraulic jack and a computer to operate the loading system we loaded it. Every 0.5 tonnes we would stop and using pencils mark out any cracks visible.
Using the software, we were able to track the displacement and compare this to hand calculations we performed as part of the coursework. You can see in the picture below the failure of the concrete beam after 14 tonnes were applied.