BCE063 – REPAIR AND REHABILITATION OF STRUCTURES
Time: 3 Hours | Max Marks: 70
SECTION A – Short Answer Questions
(2 × 7 = 14 marks | Attempt ALL)
Write definition + 1–2 key points
Important Questions with Ready Explanations
1. Common Causes of Deterioration in RCC Structures
Two common causes are: Corrosion of reinforcement
Poor quality concrete / improper curing
2. Factors Affecting Permeability of Concrete
Water–cement ratio Degree of compaction
Curing conditions Presence of cracks
3. Ferrocement and Its Uses
Ferrocement is a thin composite made of cement mortar reinforced with wire mesh.
Uses: Water tanks, shells, repair works, roofing units.
4. Repairs for Marine-Exposed Structures
Marine structures need: Anti-corrosion treatments
Protective coatings Cathodic protection
Use of special concrete with low permeability
5. Low Member Strength
Low member strength means insufficient load-carrying capacity due to deterioration or design deficiency.
Addressed by: Jacketing, FRP wrapping, steel plates, section enlargement.
6. Role of Data Acquisition Systems in Health Monitoring
They collect, store, and analyze structural data such as strain, vibration, and displacement for early damage detection.
7. Difference Between Repair and Rehabilitation
Repair: Restores original condition
Rehabilitation: Improves strength, durability, and service life beyond original state
SECTION B – Medium Answer Questions
(7 × 3 = 21 marks | Attempt ANY THREE)
Write cause → explanation → example
1. Causes of Distress in Concrete Structures Poor design and detailing
Construction defects Environmental exposure
Overloading Lack of maintenance
Examples: Cracks, spalling, deflection, corrosion.
2. Mechanism of Corrosion in RCC Carbonation or chloride ingress reduces alkalinity
Passive layer on steel breaks Electrochemical reaction causes rust
Rust expansion leads to cracking and spalling Corrosion reduces durability and service life.
3. Short Notes
(i) Fiber Reinforced Concrete (FRC)
Concrete mixed with fibers to improve tensile strength, crack resistance, and ductility.
(ii) Bacterial Concrete
Uses bacteria to heal cracks by calcium carbonate precipitation.
4. Repair vs Strengthening | Retrofitting
Repair: Fixes damage Strengthening: Increases load capacity
Retrofitting: Used when structure is unsafe under revised loads (earthquake, code changes)
5. Non-Destructive Testing (NDT) Techniques
Rebound hammer Ultrasonic pulse velocity
Half-cell potential Ground-penetrating radar
Different techniques suit different structures depending on damage type.
SECTION C – Long Answer (Condition Assessment)
(7 marks)
1. Major Causes of Deterioration & Environmental Effects
Chemical attack Freeze-thaw action
Chloride ingress Sulphate attack
Environment accelerates corrosion and cracking.
2. Condition Assessment Procedure
Step-by-step: Visual inspection
Preliminary investigation NDT testing
Sampling and lab testing Structural evaluation
Decision on repair/rehabilitation
