Determination of Residual Fracture Toughness and Softening Traction separation Law of Post fire Concrete

Abstract:

Investigations on the softening feature of post fire concrete was implemented in present research by adopting the bilinear softening traction separation law at room temperature. A new parameter λ, which directly influenced on the shape of softening curve, was introduced. According to initial fracture toughness and unstable fracture toughness determined by the wedge splitting method and the quantitative relationship among initial fracture toughness, unstable fracture toughness, and cohesive fracture toughness, the softening constitutive curve of post fire concrete was obtained through adjusting the parameter λ. It is concluded that the softening traction separation law obtained at room temperature with minor adjustments can also be applied to describing the softening feature of post fire concrete.