RC structural wall with unbonded tendons strengthened with high-performance fiber-reinforced concrete
- 323 Downloads
A new technique based on the use of high-performance fibre-reinforced concrete (HPFRC) in seismic structural walls with unbonded tendons is investigated herein. The aim of using this kind of structural wall, which develops a rocking behaviour under horizontal loading, is to limit or avoid damage during seismic events. The technique consists of strengthening the base of reinforced concrete (RC) walls provided with unbonded tendons by replacing the regular concrete at the wall toes with HPFRC, which can enhance the wall properties and be used to strengthen or repair existing RC walls. A full-scale test was performed on a rocking wall, before and after strengthening at the wall toes. Local deformations at the toes were measured in detail to quantify the extent of concrete damage in relation to wall drift and to assist future theoretical modelling. The results show that the strengthening technique can considerably limit damage at the ultimate state.
KeywordsStructural walls High-performance fibre-reinforced concrete Rocking walls Experimental full-scale test Seismic design
The experimental test was partly financed by MIUR (Ministry of Education, University and Research) as part of PRIN 2004 (Research Programme of National Interest). The contribution of UNIECO S.c.r.l., Calcestruzzi S.p.A., Ferriera Valsabbia S.p.A. and Axim Italia S.p.A. allowed the construction of the experimental wall apparatus. The wall strengthening material was kindly offered by Tecnochem Italiana S.p.A. The authors gratefully acknowledge all the supporters. The authors are grateful to P. Spatti, D. Finazzi, L. Zanetti, M. Salami and D. Fiorillo, who assisted us in designing and testing the wall, and to the staff of Brescia University’s P. Pisa Laboratory. Lastly, our special thanks go to Prof. Ezio Giuriani for his fruitful discussions with us and his invaluable suggestions.
- 1.Mander JB, Cheng C-T (1997) Seismic resistance of bridges based on damage avoidance design. NCEER, technical report 97-0014, December 10Google Scholar
- 2.Kurama Y, Sause R, Pessiki S, Lu LW, El-Sheikh M (1998) Seismic design and response evaluation of unbonded post-tensioned precast concrete walls. Precast seismic Structural Systems (PRESSS), Rep. no. 98/03, Lehigh University, Lehigh, Pa., Rep. no. EQ-97-01Google Scholar
- 6.Marini A, Riva P, Fattori L (2007) Repair and retrofitting of structural RC walls by means of post-tensioned tendons. In: Proceedings of the 6th international conference on fracture mechanics of concrete and concrete structures 2, Catania, Italy, pp 1157–1165Google Scholar
- 8.Preti M, Marini A, Metelli G, Giuriani E (2009) Full scale experimental investigation on a prestressed rocking structural wall with unbonded steel dowels as shear keys. In: Proceedings of the XIII conference ANIDIS 2009, Bologna, ISBN 978-88-904292-0-0Google Scholar
- 11.CEN (2009) EN 12390-3:2009—testing hardened concrete—part 3: compressive strength of test specimens. European Committee for Standardization, BrusselsGoogle Scholar
- 12.CEN (2004) Eurocode 2: design of concrete structures, part 1–1: general rules and rules for buildings, EN 1992-1-1: 2004. European Committee for Standardization, BrusselsGoogle Scholar
- 13.NEHRP (2004) NEHRP recommended provisions for seismic regulations for new buildings and other structures (FEMA 450), 2003 edn—part 1. Building Seismic Safety Council—National Institute of Building Sciences, Washington, DCGoogle Scholar