Structural rehabilitation and safety are directly related with each other. Usually the structures which are pushed to ‘unsafe’ zone are taken up for their rehabilitation so safety stands on highest priority for all activities under structural rehabilitation.
1.Design Stage:
While designing the rehabilitation method / scheme; cognisance of test results (destructive and non-destructive) is essentially taken. The parameters which are deteriorated are identified under the exercise and the design is prepared to recoup those lost parameters. Care is taken for designing the rehabilitation methodology for critical structures like industrial structures, structures in high-risk seismic zone, coastal structures etc to provide an incremental factor of safety. This is to sustain of higher magnitude of damage expected to affect the structure.
2.Pre-requisites stage:
Once the design is ready, specific and tailor-made pre-requisites are implemented at site. This is the stage where maximum thrust is given to safety measures. If only part structure is to be taken up for rehabilitation, then safety of other part is of high importance to ensure that its stability and soundness is not endangered during rehabilitation of the damaged part of the structure. The part of structure which is not to be taken for rehabilitation is to be properly propped and tied up with external means such that it does not develop structural damages.
3.Execution stage:
The most important stage is execution stage. Removing the damaged portion from the member should be carried out to NOT to exceed standard provisions. Time of the total activity of rehabilitation forms a governing factor in deciding the safety factor to be attached to it. Monitoring the pressure for injection grouting, erecting fresh reinforcement, managing heat of hydration / polymerisation of ingredients of rehabilitation matrix, ensuring strong and sound formwork with strutting, (compensating the pressure exerted by rehabilitation matrix on the formwork tends to deform the formwork) etc are to be very meticulously executed by reviewing each one through critical eyes.
4.Post execution stage:
Safety precautions don’t end with completion of the execution. Post execution care is equally necessary to end up the entire activity without a safety mishap. De-shuttering attracts maximum attention. Reinstatement of finishes or services on rehabilitated surface requires specific address to safety factor to ensure that it is carried out after the member has been completely cured and hydrated.