Macro-Defect Free paste

The tensile strength of classic cement pastes conforms to the curve plotted on the basis of the Griffith s equation, at the assumption that the width of crack is about 1 mm. The further part of this curve corresponds to the data obtained by Birchall [97], for the specially prepared macro defects free pastes (Fig. 5.40). These pastes are discussed in Chap. 9. They exhibit significantly higher strength because the macropores do not exceed 90 pm. 

In eighties of twentieth century the two new technologies of very high strength cement pastes were developed the DSP— Densifted Systems containing homogeneously arranged ultra-fine Particles (in Denmark), and the MDF— Macro Defects Free Cements. 

Silsbee, M R., Roy, D.M., and Perez-Pena, M. (1991b) A view of macro-defect-free (MDF) pastes. Materials Research Society Symposium Proceedings 179, 145-156. 

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