Structure of cement composites

The term structure of a material covers the distribution of its components in space and the set of relations between them which are characteristic for the material. The characterization of a material structure also comprises data on the properties of the components. 

The description of a material structure may be based either on assumptions related to an idealized perfect structure or on an analysis of a real structure. In most cases, both approaches are considered and their results are combined. The differences between these two approaches are caused by natural deviations of real structures from ideal models, and by local imperfections of different kinds. For example, the homogeneity of a material is often assumed as an approximation at a given level of analysis and when a material at lower level is considered then its heterogeneous nature becomes obvious. When the models of materials at various levels are built, they are interrelated in a systematic way, or more precisely, the models on a considered level are deduced from the results observed at a lower level (cf. Chapter 2). 

Cement based composites are highly heterogeneous and their structures are composed of different elements (Brandt 2003)  

A special category of components are also interface contact zones and various kinds of interfaces (ITZ - interface transition zone)  

The interface is understood as the region of direct contact between the two adjacent materials or material phases. The properties of interfaces are related mainly to the roughness of material surfaces, their purity, the ability of the wetting of one material by the other and to particular conditions in which thin layers of binders are hardening. 

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Structure of cement composites Popovics (1979) and many others. 

Structure of cement composites 163 Table 6.3 Parameters of air pore structures in concretes A and B... 

Structure of cement composites corresponding to one single fibre. 

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