CE-803-C Retrofitting and Rehabilitation of Structures - May 2022 Question Paper

Under each question, How to answer lists the points an answer should cover, outlined by CampusPrep from the syllabus. Check the details against your textbook.

1. 7 Marks
   aExplain the following terms:

   1. i)Repair
   2. ii)Rehabilitation
   3. iii)Strengthening
   4. iv)Retrofitting
   How to answer

   • Define Repair as restoring function/appearance after deterioration.
   • Define Rehabilitation as restoring to required performance level.
   • Define Strengthening and Retrofitting with purpose and examples.
   • Distinguish between the four terms clearly.
2. 7 Marks
   bWhat are the causes of distress and deterioration of concrete?
   How to answer

   • List material, environmental and structural causes.
   • Explain concrete deterioration mechanisms like corrosion, sulphate attack, alkali-aggregate reaction.
   • Explain distress due to overloading, temperature, shrinkage, poor workmanship.
   • Summarize effect on serviceability and strength.
3. 7 Marks
   aHow do you carry out physical inspection of distressed concrete structures?
   How to answer

   • State objectives of visual and physical inspection.
   • Describe steps: preliminary survey, mapping cracks, spalling, leakage.
   • Mention tools, photography, tapping, measurement of defects.
   • Explain recording and reporting of observations.
4. 7 Marks
   bList the steps involved in evaluation of structures and explain the different aspect of detailed investigation.
   How to answer

   • List stages of structural evaluation.
   • Explain preliminary and detailed investigation aspects.
   • Cover material testing, load assessment, structural analysis.
   • Explain documentation and decision for repair strategy.
5. 7 Marks
   aWhat are the non destructive test conducted to assess the existing strength of concrete structures? Explain any one.
   How to answer

   • List NDTs: rebound hammer, UPV, pull-out, covermeter, half-cell.
   • Explain principle of any one test.
   • Explain procedure and interpretation for strength assessment.
   • Mention limitations and correlation with core strength.
6. 7 Marks
   bWhat are the different situations that call for investigation of structures?
   How to answer

   • List situations: visible distress, overloading, change of use, earthquake/fire.
   • Explain need for investigation for durability and safety.
   • Cover pre-purchase, ageing and post-disaster assessment.
   • Conclude with decision for repair/retrofit.
7. 14 Marks
   Give the classification of tests and different tests that comes under each category to assess existing distress of structures.
   How to answer

   • Classify tests into destructive, semi-destructive and non-destructive.
   • List tests under each category with purpose.
   • Explain tests for distress: UPV, rebound, core, chemical, corrosion.
   • Relate test choice to type of distress observed.
8. 7 Marks
   aExplain in detail regarding mechanism of temperature variation in concrete and their remedial measures.
   How to answer

   • Explain thermal stresses due to temperature gradient and restraint.
   • Describe cracking mechanism in mass and reinforced concrete.
   • List factors: coefficient of thermal expansion, curing, exposure.
   • Suggest remedial measures like joints, insulation, low-heat cement.
9. 7 Marks
   bExplain the importance of concrete cover in RCC structures.
   How to answer

   • Define concrete cover and its protective role.
   • Explain protection against corrosion, fire and carbonation.
   • State code requirements for cover thickness and durability.
   • Explain effect of inadequate cover on service life.
10. 7 Marks
    aWhat are the factors to be considered by the designer at the construction site?
    How to answer

    • List site factors: soil, climate, materials, workmanship.
    • Explain design considerations for loads, exposure, drainage.
    • Cover quality control and supervision aspects.
    • Conclude with durability-oriented design decisions.
11. 7 Marks
    bWhat preventive measure will ensure protection against corrosion in New Structures?
    How to answer

    • List preventive measures: adequate cover, low permeability concrete.
    • Explain use of coated bars, inhibitors, proper curing.
    • Mention design detailing to avoid ingress of chlorides/moisture.
    • Emphasize quality control and maintenance planning.
12. 7 Marks
    aDefine maintenance. Explain the importance of maintenance.
    How to answer

    • Define maintenance and its types.
    • Explain importance for service life, safety and economy.
    • Discuss preventive vs corrective maintenance.
    • Give examples of maintenance activities in buildings.
13. 7 Marks
    bDiscuss the rehabilitation techniques that are adopted for structural elements.
    How to answer

    • List rehabilitation techniques for beams, columns, slabs.
    • Explain jacketing, plate bonding, FRP wrapping.
    • Describe grouting, stitching and external prestressing.
    • Mention selection criteria based on damage level.
14. 7 Marks
    aExplain restoration of column by method of Jacketing.
    How to answer

    • Define jacketing and its purpose for columns.
    • Describe steps: surface preparation, reinforcement, concreting.
    • Mention types: RCC, steel and FRP jacketing.
    • Explain quality checks and strength gain.
15. 7 Marks
    bClassify and explain the use of different techniques for repair.
    How to answer

    • Classify repair techniques by purpose and material.
    • Explain grouting, guniting, epoxy injection, patching.
    • Describe use for cracks, spalling and corrosion damage.
    • Compare suitability for different defect types.