According to Indian Roads Congress (IRC) standards, which loading class is generally adopted for bridges located in industrial areas or on prestigious routes like National Highways?
- AIRC Class B loading
- BIRC Class A loading
- CIRC Class AA or Class 70R loadingCorrect
- DIRC Class C loading
Solution
Concept
IRC Bridge Loading Standards
Formula
N/A
Step-by-step solution
1. Identify the IRC loading standard required for heavy traffic in industrial areas and National Highways. 2. Recall that IRC Class AA or Class 70R loading is designed for extremely heavy and heavy-duty traffic. 3. Select Option C as the correct choice.
Explanation
IRC Class AA or Class 70R loading is designed to handle extremely heavy loads, such as heavy machinery, commercial freight, and military vehicles. Because National Highways and industrial areas carry this heavy and heavy-duty traffic, bridges on these routes are designed using these higher loading standards to ensure safety and structural strength.
Shortcut
To remember IRC bridge loading for Industrial Areas and National Highways, use the rule "Heavy Industry = Top Grade (AA / 70R)": - Class AA / 70R: Think "Above Average" heavy loads (industrial machinery, freight, military vehicles) used for National Highways and industrial routes. - Class A: Standard loading for regular permanent bridges. - Class B: Temporary or timber bridges.
Common mistake
A common mistake is selecting Option B (IRC Class A loading) by assuming that because Class A is the standard loading used for all permanent bridges, it applies to all National Highways without exception. Students often overlook that industrial routes and heavily industrialized National Highways carry exceptionally heavy loads and military-grade traffic, which specifically require IRC Class AA or Class 70R loading standards.
Correct answer: C) IRC Class AA or Class 70R loading