Isparta City Hospital — Beam Strengthening with Carbon Plate

Strengthening a hospital is not the same job as strengthening an empty building. If the building stays in service, dust, noise and smell become three separate constraints. On the Isparta City Hospital job the work was staged section by section, and at each stage the working area was separated from its surroundings.

The method was carbon plate. A carbon laminate bonded with epoxy to the soffit of a beam raises its flexural capacity without enlarging the section. That is its greatest advantage over jacketing: ceiling height and room layout stay as they are.

Where carbon plate does its work

A carbon laminate is used to supplement the flexural reinforcement of a beam. It is bonded to the tension face and shares the load with the steel.

• In buildings whose floor loading has increased — slabs taking new equipment, archives or machinery.
• In beams that have lost section through reinforcement corrosion.
• Where a span has been enlarged or a beam penetrated.
• In buildings needing added capacity after an update to the seismic code.

The sequence of the work

Success with carbon plate depends less on the plate than on the surface preparation. The sequence is: opening up and dedusting the surface, levelling with repair mortar where needed, primer, application of epoxy adhesive, placing the plate and pressing it so no air is trapped, and the cure. Skip any one of these and the plate separates from the concrete — it is the bond that carries, not the plate.

Strengthening in an occupied building

The rules we apply in buildings that stay in use — hospitals, schools, shopping centres: the working area is separated by a dust barrier, work requiring breaking out is moved outside operating hours, ventilation is planned for the epoxy odour, and the area is handed back for use at the end of each stage.