Assertion (A): Minimum shear reinforcement using stirrups must be prov...
Assertion (A): Minimum shear reinforcement using stirrups must be provided even if TV 0.5 Tc
Reason (R): In the above statement, minimum shear reinforcement is to take care of sudden accidental increase of shear force in rare occasions.
The given assertion states that minimum shear reinforcement using stirrups must be provided even if TV 0.5 Tc, and the reason provided is that this minimum reinforcement is required to handle sudden accidental increases in shear force in rare occasions.
Explanation:
Shear reinforcement, in the form of stirrups, is provided in reinforced concrete structures to enhance their resistance against shear forces. Shear forces are developed in a structure due to various factors such as vertical loads, lateral loads, and moments. These forces tend to cause a sliding or shearing effect between the different layers of concrete and steel reinforcement.
Minimum Shear Reinforcement:
The minimum shear reinforcement requirements are specified in design codes such as the Indian Standard Code for Reinforced Concrete (IS 456:2000). According to IS 456:2000, minimum shear reinforcement should be provided when the shear force exceeds 0.5 times the nominal shear capacity of the section (TV > 0.5 Tc).
Importance of Minimum Shear Reinforcement:
The provision of minimum shear reinforcement is crucial in ensuring the safety and integrity of a structure. Even if the shear force is less than the nominal shear capacity of the section, the minimum shear reinforcement is necessary to prevent sudden failures or brittle shear failures. These failures can occur due to several reasons, including accidental overloading, dynamic loads, construction errors, and unforeseen events.
The minimum shear reinforcement acts as a backup system to handle sudden increases in shear force that may occur in rare occasions. It helps in redistributing the shear forces and preventing localized shear failures. By providing the minimum shear reinforcement, the structure becomes more resistant to shear forces and can withstand unexpected or abnormal loading conditions.
Conclusion:
In conclusion, the assertion (A) is true as minimum shear reinforcement using stirrups must be provided even if TV 0.5 Tc. The reason (R) provided is also true as the minimum shear reinforcement is required to handle sudden accidental increases in shear force in rare occasions. Therefore, both the assertion and the reason are true, and the reason correctly explains the assertion.