Why is Concrete weak in Tension?
Many, almost all of us would have come across the statement " Concrete is weak in Tension", why is it so.........
Concrete is not a homogeneous material like steel which is strong in both tension as well as compression. It is a composite material and is obtained by mixing cementing materials, water and aggregate (and sometimes admixtures).
Interfacial Transition zone (ITZ) in concrete
The "interface zone" is the weakest link in the structure. When compressing, that interface only serves to transfer compressive stresses from one aggregate to the next. That does not require exceptional strength.
Under tension, the aggregates are trying to pull away from each other so this interfacial transition zone has to bear tensile stresses to holds the whole system together. Since its strength significantly weaker than the aggregates, so the failure is at much lower stresses.
Microscopic view of concrete mixture
Now you won't be able to forget whether concrete is weak in tension or concrete.
Comments