Geopolymer concrete is a new alternative material to conventional concrete with less carbon dioxide emissions. Researchers have reported much research on the material properties of geopolymer concrete. However, research on the behaviour of this newmaterial at the structural level is still limited, especially at a full-scale structural level. Three geopolymer concrete beams with a total height of 700mm were tested till the shear failure. The first two specimens were subjected to the monotonically increasing load until the shear failure. The third specimen was first loaded under sustained load at the level of 80 kN for three weeks to investigate the influence of shrinkage and creep on the cracking behaviour. Then the specimen was then unloaded and reloaded again to failure. Digital Image Correlation (DIC) measurement was used to measure the surface deformation of the whole span of the beam. The crack spacing, crack width and crack development were investigated using the DIC measurement. The experimental results showed that the shear capacity of tested geopolymer concrete beams is lower than the calculated result based on the Eurocode.@en

For reinforced concrete members without shear reinforcement, the shear failure is characterized by the formation of a critical flexural shear crack. Recently experimental observations making use of Digital Image Correlation (DIC) by many researchers suggested the significance of geometric characteristics and kinematic conditions of critical shear cracks in shear failure. However, limited efforts were reported in literature on the quantification of the geometric characteristics of critical shear cracks. This is mainly due to the lack of understanding of the mechanism of how the flexural shear cracks form. In this paper, the available models in literature for the shear crack trajectory and the underlying theoretical assumptions are reviewed first. Those models include the shear crack model proposed by the authors. Next, the shear crack trajectory models are validated using a collection of shear crack patterns based on the DIC data obtained from the shear failure database from Delft University of Technology. The majority of the crack patterns are from full-scale shear tests of deep beams with an effective depth larger than 1.0 m. The comparison helps us to have a basic understanding of how accurate the available flexural shear crack trajectory models can achieve.@en