Engineered Cementitious Composites for the Conservation of 20th Century Concrete Architectural Heritage

Abstract

Architectural heritage nowadays includes concrete structures constructed in the 20th century. These buildings are usually under-detailed, since the actual behavior of reinforced concrete at the time of their construction was not clearly understood, whilst building codes incorporating seismic resistance design, especially in seismic prone areas, did not exist. This inevitably led to inefficient design and consequently to severe damages in many historic concrete buildings during past seismic events. This paper explores the use of novel Engineered (Fiber Reinforced) Cementitious Composites (ECCs), with strain hardening abilities in tension, for the repair and strengthening of old sub-standard reinforced concrete columns, focusing on their confining and shear strengthening potentials. The experimental results show that, when replacing the reinforcement cover with fiber reinforced ECCs, the fibers bridge tensile cracks, limiting their opening and increasing their resistance against volumetric expansion, ultimately leading to increased amounts of energy dissipation. ECCs may thus by used in the repair of historic concrete structural elements.