Densified systems and articles made therefrom which contain a composite material comprising a coherent matrix of homogeneously arranged inorganic particles (A) of a size of from about 50 .ANG. to about 0.5 3/4, such as silica dust, and densely packed particles (B) having a size of from 0.5-100 .mu. such as Portland Cement and which are at least one order of magnitude larger than the particles A, and embedded in the matrix, solid particles C made from material having a strength exceeding that of ordinary sand and stone used for ordinary concrete, such as refractory grade bauxite and a surface active dispersing agent. Particles A are homogeneously distributed and especially densely packed, in the void volume between the particles B and are made from an easily flowable composite material containing a very low amount of liquid such as water and an extremely high amount of a dispersing agent such as a concrete superplastisizer. High quality concrete made from a Portland Cement/silica dust matrix with refractory grade bauxite embedded therein exhibits high compressive strength and may be used as a replacement for plastic, glass and steel. High performance fiber/metal matrix composites with substantially improved compressive strength and abrasion resistance are produced.