Evolution of the Theory of Concrete Strength. From Simple to Complex
A model of the structure of cement composites based on the principles of the fractal geometry according to which the complex systems of nature consist of parts (fractals), which ateach scale level is like the whole, is proposed. It is shown that the classical theory of strength does not reflect the real picture of the resistance of fractal structures to destruction. It isexperimentally and theoretically proved that the destruction of cement composites is a multi-level, multi-stage process; under the action of compressive loads, the concrete structurecan be destroyed both by cleavage and by cutting; a fractal model more exactly describes the relation between compression and tension, scale effect, dependence of compressionstrength on the friction coefficient. Deformation diagrams obtained with the use of the software complex “Welle Geotechnik” confirm the discrete-continuous character of the destructionof cement composites under compression.