Highly compressible concrete: The effect of reinforcement design on concrete’s compressive behavior at high strains

Abstract

In squeezing ground tunnel construction, yielding elements must absorb the large tunnel deformation without damaging the tunnel lining. Various designs for these highly compressible structures exist. Still, they all share one commonality: they are complicated to manufacture, and it is difficult to alter their design to match desired compressive properties. A new yielding element design is presented here, consisting of corrugated metal plates embedded within fiber-reinforced concrete. As this yielding element is compressed, the corrugated plates are gradually flattened, increasing the plates’ stiffness. This mechanism enables the engineering of structures with monotonically increasing compressive stress–strain curves and matches the target compressive properties. When compared against alternate reinforcement schemes, including fiber reinforcement, flat plate reinforcement, and polymeric lattice reinforcement, compression results indicate that only the corrugated metal plate reinforcement produced monotonically increasing stress–strain curves while keeping stress levels below a prescribed limit. Additionally, the corrugated metal plate-reinforced specimens began densification at a strain 280% larger than the strain at which the fiber-reinforced samples began densification, indicating that the corrugated metal plates extended the yield plateau. Fiber-reinforced concrete in conjunction with corrugated metal plates shows promise for use as a yielding element.