Rehabilitation is the process of restoring a structure to its service level, once it has been lost or weakened. Strengthening consists of providing the structure with a higher level of service than initially planned by modifying the structure, even if it is not necessarily damaged. The deterioration of reinforced concrete structures is a major problem worldwide, and many structures require extensive repairs and rehabilitation. Over time, these structures suffer from degradation or deterioration, resulting in deformation such as cracking, splitting, delamination, corrosion, etc. Due to the increase in construction activities over the past two decades, many structures are already showing signs of distress.
In some cases, repair measures are necessary even within a period of 5 to 10 years after the completion of the structure. This can be caused by poor quality concreting materials, poor workmanship, lack of maintenance, atmospheric effects, abuse, accidents or natural disasters. Therefore, adapting a concrete structure becomes necessary to extend its service life and ensure its durability. Rehabilitation provides for the restoration of the structural system as close as possible to its original position. The worn structure must be brought into line, leveled and with the required strength so that it can be put into service without jeopardizing its safety and usefulness. In order to collect data for the design of structural rehabilitation of a structure, an extensive on-site research campaign must be carried out.
At present and at European level, no well-established design and detail calculation methods have been developed that cover all techniques for the on-site use of composite rehabilitation systems in wood and concrete structures. SRPL is also expanding consulting services to find intellectual solutions for repairs and rehabilitation of CCR structures by performing appropriate non-destructive testing using the latest state-of-the-art non-destructive testing equipment. All fiber types are available in various fiber forms and architectures, corresponding to the manufacturing processes, but also according to the requirements of FRP composites for structural rehabilitation. As FRPs are non-corrosive and have high specific strength and modulus values compared to their density, their light weight, custom design, acceptable deformability and excellent formability allow the manufacture of new elements and the structural rehabilitation of existing parts made of traditional materials. During repair and rehabilitation, special attention should be paid to areas such as foundations, basements, bathrooms, balconies and roofs which are very prone to water damage and also to symptoms of distress that endanger structural stability. Taking this evidence into account, the structural rehabilitation design also considered the reconstruction of the structurally most important parts of the building with new marble elements produced in the same way as the originals. Before finalizing any plan for the repair and rehabilitation of a worn concrete structure, it is essential that an expert is fully aware of the causes of danger, extent of damage to the structure and current state of concrete in the structure.
For any repair & rehabilitation work it is always better to trust the manufacturer in various aspects such as material & its suitability for that particular type of work. Therefore, for most applications designers of wooden structures will have to rely primarily on their individual skills and experience to properly design and detail composite rehabilitation work. Other methods for repair & rehabilitation include prepackaged concrete, epoxy injection bonding under pressure, routing & sealing, grouting etc. The infographic below presents some chimney repair & rehabilitation projects they have carried out. The repair process for internal strengthening does not require excavation of a trench; therefore FRP composite lining becomes a trenchless structural rehabilitation. Carbon fiber & epoxy resin coatings have been used for complete structural repair & strengthening & rehabilitation of onshore steel pipes. The results from this durability study indicate strong potential for CFRP coating system to work well as a long-term solution for pipeline rehabilitation.
However development of appropriate design guidance standards is much more advanced in case of rehabilitation of concrete structures than wooden structures.
