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

Reyes Garcia,Iman Hajirasouliha,Maurizio Guadagnini,Yasser Helal,Yaser Jemaa,Kypros Pilakoutas,Philippe Mongabure,Christis Chrysostomou,Nicholas Kyriakides,Alper Ilki,Mihai Budescu,Nicolae Taranu,Mihaela Anca Ciupala,Lluis Torres,M Saiidi

doi:10.1080/13632469.2013.847874

Abstract

The effectiveness of a novel Post-Tensioned Metal Strapping (PTMS) technique at enhancing the seismic behavior 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. While the bare building experienced critical damage at an earthquake of PGA = 0.15 g, the PTMS-strengthened building sustained a PGA = 0.35 g earthquake without compromising stability.

Highlights

Recent severe earthquakes in developing countries (Kashmir, 2005; China, 2008; Indonesia, 2009; Haiti, 2010) caused numerous casualties and financial losses due to the collapse of many reinforced concrete (RC) buildings
The results indicate that, due to damage accumulation produced by the shaking in the X direction, the initial stiffness of the building in Phase 3 reduced by 62% and 41% in comparison to the bare building (KiY=6600 kN/m, beginning of Phase 1) and after the Post-Tensioned Metal Strapping (PTMS) strengthening (K=4260 kN/m, beginning of Phase 2), respectively
This paper presents the results of the first three testing phases of the EU-funded project BANDIT

Summary

Introduction

Recent severe earthquakes in developing countries (Kashmir, 2005; China, 2008; Indonesia, 2009; Haiti, 2010) caused numerous casualties and financial losses due to the collapse of many reinforced concrete (RC) buildings. Many structural failures were attributed to the inadequate behaviour of beam-column joints. Typical deficiencies in joints may include [Beres et al, 1996]: 1. Short anchorage length of bottom beam reinforcement in joint core, and 3. The local strengthening of substandard joints is essential to reduce the seismic vulnerability of such deficient buildings. Different techniques have been used for the repair and strengthening of substandard exterior RC beam-column joints, including: Crack injection and/or epoxy mortar repair [e.g. Karayannis et al, 1998] Concrete/shotcrete jacketing [e.g. Corazao and Durrani, 1989; Karayannis et al, 2008; Tsonos, 2008; 2010] Steel jacketing or steel plates [e.g. Corazao and Durrani, 1989; Ghobarah et al, 1996; Biddah et al, 1997; Sasmal et al, 2011] Externally bonded fibre reinforced polymers (FRP) [e.g. Different techniques have been used for the repair and strengthening of substandard exterior RC beam-column joints, including: Crack injection and/or epoxy mortar repair [e.g. Karayannis et al, 1998] Concrete/shotcrete jacketing [e.g. Corazao and Durrani, 1989; Karayannis et al, 2008; Tsonos, 2008; 2010] Steel jacketing or steel plates [e.g. Corazao and Durrani, 1989; Ghobarah et al, 1996; Biddah et al, 1997; Sasmal et al, 2011] Externally bonded fibre reinforced polymers (FRP) [e.g. Gergely et al, 2000; Granata and Parvin, 2001; Ghobarah and Said, 2001; 2002; Antonopoulos and Triantafillou, 2003; Said and Nehdi, 2004; Ghobarah and El-Amoury, 2005; Pantelides and Gergely, 2008; Karayannis and Sirkelis, 2008; Tsonos, 2008; Akguzel and Pampanin, 2010; Alsayed et al, 2010; Le-Trung et al, 2010; Parvin et al, 2010; Al-Salloum et al, 2011; Ilki et al, 2011; Sezen, 2012]

Objectives

Methods

Findings

Conclusion