Steel rebar, the world’s favorite reinforcement material for concrete, greatly increases tensile strength in concrete. Due to concrete’s rigidness and tendency to shrink and expand, reinforcement is necessary in many cases to reduce cracking and slow structural failure. This material is elementary to most of throughout the construction industry, but what you may not be familiar with is how much stress steel rebar must be under before it completely snaps in half.
Gav and Dan, also known as The Slow Mo Guys, have amassed a huge youtube audience simply by filming awesome things, mostly exploding, in super slow motion. Their most recent video shows what it looks like when a piece of #11 grade 60 steel rebar, which measures 1.41 in (35.81mm) in diameter, is put under enough force to completely snap it in half. The force is measured in kips, which the guys called “pulling apart force” (technical term), one of which equals 1000 pounds-force.
The experiment, which was filmed at the University of Purdue’s College of Engineering, showed that it took 157.401 kip of force, or 157,401 pounds of force, before the rebar broke. Watching the footage slowed down to 28,000 frames per second (fps) and again at 148,000fps allows you to see the millions of steel particles that explode into the air as the steel breaks.
On Tuesday morning, February 23, the Syracuse Fire Department responded to a call about a collapsed crane on a construction site near the university. Thankfully, no injuries were reported.