Seismic retrofitting of RC buildings using CFRP and post-tensioned metal straps: shake table tests

This article examines the effectiveness of two innovative retrofitting solutions at enhancing the seismic behaviour of a substandard reinforced concrete building tested on a shake table as part of the Pan-European funded project BANDIT. To simulate typical substandard construction, the reinforcement of columns and beam-column joints of the full-scale structure had inadequate detailing. An initial series of shake table tests were carried out to assess the seismic behaviour of the bare building and the effectiveness of a first retrofitting intervention using Post-Tensioned Metal Straps. After these tests, columns and joints were repaired and subsequently retrofitted using a retrofitting solution consisting of Carbon Fibre Reinforced Polymers and Post-Tensioned Metal Straps applied on opposite frames of the building. The building was then subjected to unidirectional and three-dimensional incremental seismic excitations to assess the effectiveness of the two retrofitting solutions at improving the global and local building performance. The article provides details of the above shake table testing programme and retrofitting solutions, and discusses the test results in terms of the observed damage, global damage indexes, performance levels and local strains. It is shown that whilst the original bare building was significantly damaged at a peak ground acceleration (PGA) of 0.15g, the retrofitted building resisted severe threedimensional shake table tests up to PGA=0.60g without failure. Moreover, the retrofitting intervention enhanced the interstorey drift ratio capacity of the 1st and 2nd floors by 160% and 110%, respectively. Therefore, the proposed dual retrofitting system is proven to be very effective for improving the seismic performance of substandard buildings.

Full-Scale Shaking Table Tests on a Substandard RC Building Repaired and Strengthened with Post-Tensioned Metal Straps

The effectiveness of a novel Post-Tensioned Metal Strapping (PTMS) technique at enhancing the seismic behaviour of a substandard RC building was investigated through full-scale shake-table tests during the EU-funded project BANDIT. The building had inadequate reinforcement detailing in columns and joints to replicate old construction practices. After the bare building was initially damaged significantly, it was repaired and strengthened with PTMS to perform additional seismic tests. The PTMS technique improved considerably the seismic performance of the tested building. Whilst the bare building experienced critical damage at an earthquake of PGA=0.15g, the PTMS-strengthened building sustained a PGA=0.35g earthquake without compromising stability.

Fighting Talk: The Statements of 'The IRA/New IRA'

With the advent of the new violent dissident merger, ‘The IRA/New IRA’, the group and its affiliates have had to legitimise their new existence. They have utilised the maintenance of paramilitary activity to achieve this. However, they have also produced a number of organisational statements, justifying their position, tactics and strategies. This article analyses the evolution of these statements, both pre and post-merger from 2007 to 2015. 126 individual statements and 4 magazines are analysed using grounded theory. This analysis found that the statements have a dual strategy, aiming to foster trust in the movement and distrust in their perceived enemies. One of the dominant ways in which the group aims to foster trust, is by proposing their possession of an historical mandate from the republican forefathers of 1916, as well as the internally lauded paramilitaries from the Troubles era PIRA. The focus of the distrust narrative has been on the ‘constitutional nationalism’ of Sinn Féin. However, it also pours scorn on the PSNI, and capitalism, across the island of Ireland. The analysis of these statements can provide us with an understanding of the future direction of the group, as well as giving us insight, which can inform the development of any counter-narrative.