Measurement on fracture process and prediction of the load capacity of steel fiber reinforced concrete by electronic speckle pattern interferometry

Electronic speckle pattern interferometry (ESPI) was used to measure the fracture process of the steel fiber reinforced concrete (SFRC) specimen with prenotch under three-point bending in this paper. Two kinds of powerful phase measurement techniques, phase shifting method (PSM) and spatial-carrier method (SCM), were described briefly. From the quantitative analysis of ESPI fringes under different load levels, the crack opening displacements (CODs), crack mouth opening displacements (CMODs) and neutral layer positions were obtained. Using the displacement data, the maximum load of the beam was predicted through double-K fracture model.