Why is the compressive strength of reinforced concrete important and measured via cylinder breaks during construction?
The answer to this questions lies within one of the most basic concepts of reinforced concrete behavior. When a beam, slab or column is loaded, some parts of the element go into compression and some parts go into tension. In designing the structure, the engineer will determine both how much compression and tension in “pounds per square inch” (psi) each element will see when loaded. Calculating these forces then allows the engineer to properly select the concrete design mix compression strength and the amount of rebar to meet the loads. Slabs/Beams (bending controlled behavior) vary in concept from columns (compression controlled behavior). • For Beams and Slabs – When a load is applied to a slab or beam, the element will deflect downward. In order for this to happen, the bottom of the slab or beam must “stretch” – or become longer. Any material that becomes longer must go into Tension. However, concrete itself is actually very weak in tension which is why an engineer places reinforcing
