ABSTRACT
Composite materials are multi-phase materials obtained by artificial combination of different materials in order to attain properties that the individual components by themselves cannot attain. An example is a lightweight structural composite that is obtained by embedding continuous carbon fibers in one or more orientations in a polymer matrix. The fibers provide the strength and stiffness, while the polymer serves as the binder. Another example is concrete, which is a structural composite obtained by combining (through mixing) cement (the matrix, i.e., the binder, obtained by a reaction, known as hydration, between cement and water), sand (fine aggregate), gravel (coarse aggregate) and other optional ingredients that are known as admixtures. Short fibers and silica fume (a fine Si0 2 particulate) are examples of admixtures. In general, composite are classified according to their matrix material. The main classes of composites are polymer-matrix, cement-matrix, carbon-matrix and ceramic-matrix composites.
