Impact crack extension modes

A test may typically involve the extraction of force P and energy associated with the initiation of crack extension from an instrumented impact load-deflection trace (see Fig. 7) for a test conducted in three-point bending mode (Charpy arrangement). The associated fracture stress can be calculated from... 

As it is commonly known and applied for a long time, the properties of paste can be improved by reinforcement with the fibres. For example, the production of asbestos-cement materials started 80 years ago. The fiber reinforcement technology has been developed extensively for the last 20 years and the other fibres has been taken into account, first of all the steel fibres, but also the carbon, glass, resin, polypropylene and cellulose fibres as well. The fibres reinforcement gives the pos-sibihty to enhance the flexural and tension strength, as well as the impact resistance. The fibre composite modifies the properties of concrete by control cracking and the mode of failure by means of post—cracking ductility. 

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