Retrofitting and Rehabilitation of Civil Engineering Structures

• Once problems are clearly identified and objectives have been set, a timetable for repair is established in close consultation with the property owner that is in keeping with the findings of the evaluation.

• First and foremost, the contractor must comply with the drawing details and specifications. To further ensure the durability of the repair, repair procedures and selection of the repair materials must be compatible with the substrate.

FIRST STEP: To find out causes

• The causes can be discussed as follows (Investigated).

• Assessment damaged by earthquake , blasts, fire, functionally deteriorating.

• Assessment of quality of construction.

• Assessment of structure for further expansion.

• Assessment of ageing structures by non destructive tests, Load tests, etc,.

Types of Construction Site Accidents

• Construction site falls.

• Crane accidents.

• Scaffolding accidents.

• Run over by operating equipment

• Electrical accidents.

• Trench collapses.

• Fires and explosions

HOW TO CARRY IT??

• It is only by the “NON DESTRUCTIVE TESTS”

We obviously knew why should it be a non destructive test, because we aren’t allowed to destruct the entire structure in the name of testing.

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Evaluation and Repair of Fire-Damaged Buildings

• Typically, repair materials are similar to the original construction materials.

• Timber structures may be repaired with new timbers or composites of steel and timber members, and steel structures are normally repaired with steel.

• Concrete and masonry structural elements are frequently repaired with fiber reinforced polymers (FRP) or externally bonded steel members using epoxy adhesive. Concrete structures are occasionally repaired with shotcreteas well.

• Selecting the appropriate repair material is a critical step in the repair process. The repair material must be compatible with the base material, project needs, technical resources available, financial constraints, and multiple other project specific criteria.

CASE STUDY ( REPAIR OF FIRE DAMAGED BUILDING)

Two case studies are presented to illustrate various types of structural damage and repairs.

• The first summarizes the assessment and repair for arson damage to a reinforced concrete stadium structure.

• The second addresses the evaluation and repair of damage to a steel framed office building.

Slab separation and joist spalling

Case Study 1: Stadium FireAn arson fire occurred on an elevated level of a reinforced concrete stadium structure. After the fire department approved the area for entry, initial observations were made. The fire severely damaged the concrete in an area approximately 25 feet by 25 feet above the fire; the concrete joists were deeply spalled, the slab separated from the joists, and severe cracking was present.

The fire was intense to the extent that the seating area directly above the fire suffered heat damage

Case Study 2: Occupied Steel High Rise Fire

Fire occurred in an occupied space of a steel framed high rise. The steel framing was protected by a sprayed fire resistive material. The exposed metal deck supports a composite concrete floor system.. Heat from the fire caused some buckling of the metal decks near the fire Buckled metal deck. Note separation of concrete from metal deck through exploratory opening.

The evaluation effort included steel hardness readings of the structural steel framing members. In addition, concrete cores were extracted from the floor slab where the fire occurred and in the deck directly above the fire for compression testing. No testing was considered necessary in the adjacent room with deformed plastic due to the low temperature indication. Test results confirmed that steel hardness was in the expected range to indicate minimal heat damage to the steel frame. Concrete cores indicated that compressive strengths exceeded design requirements.

The assessment concluded that the steel frame did not require repairs. However, to prevent displacements of the separated concrete slab above the metal deck, structural repairs were required . The repairs included adding new beams to support the metal deck and the addition of grout to fill the voids between the concrete and metal deck.

FINALLY

• All structures should be evaluated in a systematic manner to determine the extent, if any, of required repairs.

• A variety of testing methods and tools are available to evaluate the effects on both the materials and structural elements.

• Evaluations, combined with an engineering analysis, allow effective and economical repair details to be developed and installed as needed.

CONCLUSION

• Rehabilitation has equal importance as that of construction.

• Constructing a building is just not the talent of an engineer, he/she should be well known to repair the defects, only then, it makes them an actual civil engineer.

• It is cool for the consumers if we are capable to be a perfect engineer , which means a perfect repairing engineer as they trust us a lot.