Full-Scale Shaking Table Tests on Deficient Rc Buildings Strengthened With FRP Composites

The paper discusses the results from experimental programmes including full-scale shaking table tests on two deficient one-span two-storey RC frame buildings strengthened with Carbon Fibre Reinforced Polymer (CFRP) composites. The tests were performed at one of the world class shaking table testing facility, the AZALEE shake table at the Commissariat à l’Énergie Atomique (CEA), Laboratory in Saclay, France, as part of two European (EU) funded research projects (EU ECOLEADER project and EU FP7 SERIES/ BANDIT project). The aim of these experimental programmes was to investigate the effectiveness of externally bonded CFRP reinforcement in improving the seismic behaviour of deficiently designed RC buildings. To simulate typical substandard design, the reinforcement of beam-column joints and columns of the two full-scale frames had inadequate detailing. In both projects, initial shaking table tests were carried out to assess the seismic behaviour of the bare frame buildings. Columns and joints were subsequently repaired and strengthened using CFRP composite material for the ECOLEADER frame, and a strengthening solution consisting of CFRP composite material and Post-Tensioned Metal Straps for the BANDIT frame. The frames were then subjected to incremental seismic excitations to assess the effectiveness of the strengthening solutions in improving the global and local frame performance. Whilst the original bare frames were significantly damaged at a peak ground acceleration (PGA) of 0.15-0.20g, the strengthened frames resisted severe shaking table tests up to PGA=0.50-0.60g without failure. Moreover, the strengthening interventions enhanced the interstorey drift ratio capacity and proved to be very effective in addressing the seismic deficiencies of substandard buildings.