50 kg load cells found in bathroom scales are quite cheap to buy or pull out of an old / broken scale.
with four pieces (as provided by the scale) will be no problem holding 100 kg, a pair of them supporting one resting head of the bridge.
HX711 has two available speeds 10 and 80hz. So yes, if you send the raw readings directly to a computer via usb, there are some chances to plot a meaningful chart of what happens during or near the braking of the bridge. It depends a lot on materials, size and how abruptly it brakes. For faster readings (through arduino analog line) you’ll have to provide an amplifying circuit, the load cell signal is very weak, a few mV
I feel for this experiment great accuracy is not the concern, but the “shape” of the curve during braking is more interesting?