Strengthening of a Bridge Pier with HPC: Modeling of Restrained Shrinkage Cracking

Abstract:

After more than fifty years from the opening of the largely discussed “Autostrada del Sole” Highway in 1964, the infrastructure system in Italy appears marked by the passing of time, similarly to what observed in several other countries worldwide. The great heterogeneity of the Italian landscape has determined a great variety of construction types, such as large span concrete bridges over the northern rivers and large arch concrete bridges over the valleys of the central region. Increment of vehicle traffic and new seismic regulations are setting new requirements to adapt the existing infrastructure, which should be otherwise replaced. Moreover, reinforced concrete (RC) aging and deterioration have led to structural and material degradation, including severe cracking and corrosion. Specialized materials such as High Performance Concrete (HPC) could represent a viable convenient solution for repairing, strengthening and retrofitting of RC structures as both structural capacity and durability can be refurbished. However, alongside high mechanical performance, HPC is characterized by a high cracking sensitivity at very early age, due to its high stiffness and shrinkage. Restrained shrinkage cracking, particularly significant in repaired structures where the existing concrete generates a considerable restraint against the free movement of the repair material, may represent a limit to the effective application of these materials. For this reason, shrinkage compatibility of HPC with the existing concrete substrate needs to be experimentally and numerically assessed. A study is herein presented where, based on experimental tests, different numerical models are developed and compared to assess and eventually minimize the risk of shrinkage cracking in bridge piers strengthened with HPC.

• Periodical: Key Engineering Materials (Volume 711)
• Pages: 1027-1034
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.711.1027
• Online since: September 2016
• Authors: Adriano Reggia*, Sara Sgobba, Fabio Macobatti, Cristina Zanotti, Fausto Minelli, Giovanni A. Plizzari
• Keywords: Bridge Pier, Cracking, Fiber Reinforced Concrete (FRC), High Performance Concrete (HPC), Jacketing, Numerical Analysis, Restrained Shrinkage

References

[1] C. Zanotti, S. Talukdar, N. Banthia, A State-of-the-Art on Concrete Repairs and Some Thoughts on Ways to Achieve Durability in Repairs. Infrastructure Corrosion and Durability - A Sustainability Study, ed. Y. Lu, OMICS Group EBook, (2014).

[2] P.J. Robins, S.A. Austin, A Unified Failure Envelope from the Evaluation of Concrete Repair Bond Tests, Magazine of Concrete Research, 47 (1995), 57–68.

DOI: 10.1680/macr.1995.47.170.57

[3] Macobatti, F., Experimental and numerical study of early-age cracking in retrofitting of existing RC structures, PhD Thesis, 2015 (in press).

[4] TNO Building and Construction Research, TNO DIANA User's Manual Release 9. 6, TNO DIANA BV, Delft, The Netherlands, (2015).

[5] H.T. See, E.K. Attiogbe, M.A. Miltenberger, Shrinkage Cracking Characteristics of Concrete Using Ring Specimens, ACI Materials Journal, 100 (2003), 239-245.

DOI: 10.14359/12625

[6] EN 1992-1-1: 2004, Eurocode 2: Design of concrete structures - Part 1-1: General rules and rules for buildings.

[7] C. Zanotti, N. Banthia, G.A. Plizzari, A study of some factors affecting bond in cementitious fiber reinforced repairs, Cement and Concrete Research, 63 (2014), 117-126.

DOI: 10.1016/j.cemconres.2014.05.008

[8] CEB-FIP, Ceb-Fip Model Code 2010, Bulletin d'Information No. 65, Losanne, (2012).