I Broke These Concrete Beams - Design Principles from Beam Failures

I constructed six reinforced concrete beams in the lab and then loaded them to failure. What can we learn about reinforced concrete behavior and good design principles from these tests?

Two of the beams exhibited flexural failures with lots of flexural cracking and ultimate crushing of the concrete in compression. Two beams had traditional shear failures, with a diagonal crack extending through the section. Finally, two beams had anchorage failures, where the ends of the bars pulled out at the support. Good beam design encourages flexural failures because of its ductility and predictability.

Chapters:
0:00 Beam Fabrication
0:49 Test Setup
1:23 Beam 1 Test
2:31 Beam 2 Test
3:28 Beam 3 Test
4:19 Beam 4 Test
5:31 Beam 5 Test
6:23 Beam 6 Test
7:03 Results
8:15 Lessons Learned