Civil Engineering/RCC structure
QUESTION: Hi Dear BEH,
What is the first symptom if the RCC structure does not have sufficient steel reinforcement and it is loaded beyond the capacity. Say for example RCC roof, RCC beam or RCC column.
Just to educate my self.
I have seen in few RCC structures, cracks along the horizontal axis of the RCC beam. Is it due to the above factor ?
ANSWER: Dear Sudarshan
Cracks may have shear (shear or torsion) source or bending. When you have a beam with moment resisting supports, the failure is more likely to occur from supports and be ended in mid span. You can observe a bread stick bending and trace the cracks for your curiosity. You can take a look at the Internet too.
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QUESTION: Thank you.
From your answers I understand that if the RCC structure does not have sufficient steel reinforcement and it is loaded beyond the capacity. Say for example RCC roof, RCC beam then the first symptom is bending of the beam at the center with cracks usually at the column support and will end in the midspan.
If there are no such symptoms then the structure is with in the safe limits.
Surely not. Cracks are signs of probable damage. But no crack doesn't mean a reliable safety. Because safety has 2 branches : loading and material properties. You can be safe only when you have a reliable analysis along with site observation matching with your calculations. No magic behavior exists in this field.