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Concrete must have tremendous compression resistance strength, but I often see concrete beams, and wonder how the concrete adds any flexural strength to the int
by euroclydon 9y ago
Concrete must have tremendous compression resistance strength, but I often see concrete beams, and wonder how the concrete adds any flexural strength to the internal steel.
- dsfyu404ed 9y agoYou're seeing "reinforced" concrete beams. Parts of a beam are in compression, others are in tension and which part is in which can vary. The mechanical properties of the concrete and steel compliment each other.
- euroclydon 9y agoSo if the beam is holding a load over a span, then the concrete on the bottom of the beam, which is experiencing tensil force, is doing little? I mean, I assume concrete has poor tensile strength.
- angersock 9y agoWorse than little--it's getting pulled apart. https://www.youtube.com/watch?v=CC_yYLZac_s https://www.youtube.com/watch?v=CC_yYLZac_s
- euroclydon 9y agoThanks. That's reassuring; does not catastrophically fail.
- ghaff 9y agoConcrete's tensile strength is about 10% of its compressive strength. So, yes, unreinforced concrete is quite weak in tension.
- bluthru 9y agoThat's where the rebar is located.
- ars 9y agoFor even greater strength you pre-tension the concrete by externally stretching steel cables inside the concrete, and letting it cure. When you release the external load the concrete is under tremendous compression, and is able to easily resist tension.