Evaluation of the effect of maximum aggregate size on fracture behavior of self compacting concrete

• Fracture properties of SCC were obtained using two different methods.
• With increase of coarse aggregate size, fracture toughness increases.
• Size effect method can predict the peak load with a good precision for SCC beams.
• SCC ductility increases with increase of coarse aggregate size.

This paper presents and discusses the effect of maximum size of coarse aggregate on fracture characteristics and brittleness of self-compacting concrete (SCC). Based on an experimental program, a series of three point bending tests were carried out on 86 notched beams, as recommended by RILEM. For all mixes, the parameters were analyzed by the work-of-fracture method (WFM) and by the size effect method (SEM) and consequently a correlation between these methods was obtained which is used to calibrate cracking numerical models. Test results showed that with increase of size of coarse aggregate, (a): fracture energies of GF in WFM and Gf in SEM increase which may be explained by the change in fractal dimensions, (b); based on size effect plot, behavior SCC specimens approaches strength criterion, (c): SCC ductility, measured by means of characteristic length (Lch) in WFM and fracture process zone length (Cf) in SEM, increases. In addition, the correlation between GF and Gf values showed that the ratio GF/Gf is approximately equal to 2.94.