A basic concept of concrete design relates to how the load is applied. It’s no surprise that a concentrated load puts more stress on a structure than the same load spread over a larger area—but how much? If we calculate the stress of 20,000 pounds resting in a small area on a 20-foot span slab versus spreading that same load at 1000 pounds per foot, the concentrated load creates two times the stress! At this level, problems occur. Knowing this, always spread out construction materials, equipment, and debris onsite—and consult an engineer with technical questions.

This seminar, Engineering 101 for Contractors Part I: Reinforced Concrete Design Basics, was presented by Jay Thomas at World of Concrete 2012.