Retrofitting of low rise reinforced concrete building using external bolted plates, Case study SPS Building, Jimbaran Bali-Indonesia

This paper presents the assessment results and structural retrofitting of SPS Building. The building is a three story reinforced concrete structure with a mezzanine floor for a storage. The building was an office building with a live load of 2.5 kN/m2 and then the building function changes to be an industrial building with a live load of 10 kN/m2. The existing concrete and rebars tensile strength, structural member dimensions and configuration were assessed before structural analysis and redesign were done using a commercial software. It is found that the average concrete strength is about 11 MPa and most of existing structural members are less flexure and shear capacity. Therefore, an external flexure and shear strengthening using external bolted steel plates were applied to those members with grouting materials to fill the gaps between the steel plate and existing structural members. A strength evaluation using direct loading with a maximum water depth of 1000 mm over an area of 60 m2 to represent the live load of 10kN/m2 was conducted to ensure the retrofitting method works well. The test results show that measured deflections of beams and slabs are still less than the maximum deflection limits. This indicates that the strengthening system using external bolted steel plates can improve the member capacity to support the new design loads.