Study On Double-K Fracture Parameters Of Self-Compacting Super-Strength Concrete

Self-compacting concrete is a new engineering material. Therefore, its basic mechanics behavior is the dominant topics concerned by many academic researcher and engineering designer. With this in minds, in this paper, the experiments on five series of self-compacting concrete with different strengths are conducted with a view to investigate their mechanics behavior.With the development of structural analysis and design methods, the study on Mechanisms of fracture of concrete has been widely carried out. Besides, the double-K fracture parameters for self-compacting concrete with four different strengths of M20, M60, M100, MHO, is determined. The results show that:1. For self-compacting concrete of M20, M60,M100, of which the addition is same, the compression strength flc ,the tension strength ft,s the elastic modulus Ec of cylinder increase with the increase of the density of concrete2. The compression strength of concrete cylinder for every strength linearly varies with the change of both the tension strength and the elastic modulus, i.e. ft,s =0.0666flc +0.7877, Ec =0,01648flc +2.138.3. The initiation fracture toughness determined in terms of the different traction-separation softening function is different. This means that the different traction-separation softening curve may have influence on the value of initiation fracture toughness of self-compacting concrete.4. When the subcritical crack propagation is taken into account, the values of the initiation fracture toughness KIcini and the unstable fracture toughness KIcun determined by the double-K fracture theory increase with the increase of the strength of self-compacting concrete. Hence, it can be said that the fracture toughness of self-compacting concrete is strongly affect by the strength of concrete.