Fuzzy-logic description of stress-strain curve for hardening concrete and fiber-reinforced concrete
This paper presents a fuzzy-logic-based approach to definition of a uniaxial short-time response of hardening concrete and fiber reinforced concrete both in compression and tension. The objective in the definition was to obtain a continuous curve over the entire range of the stress-strain curve. This was achieved by formulating a method based on the classical fuzzy control and optimization of the shapes and numbers of the fuzzy sets. The distribution of the fuzzy sets for definition of the stress-strain curves was based on experimental data for concrete at early age and hardened fiber reinforced concrete. The methods are explained in examples.