A temperature dependent constitutive model for hybrid fibre reinforced concrete

The use of fibre reinforced concrete (FRC) in engineering constructions has attracted increasing attention due to its excellent performance, including its improved strength, toughness, impact resistance and fire resistance. In recent years, hybrid fibres have been used in FRC to obtain better performance. To provide a reliable predicting tool and promote the application of hybrid fibre reinforced concrete (HFRC), a constitutive model is developed in this study to mimic the behaviour of HFRC under fire condition. The governing equations of damage function and strength envelope are modified in the new model. To calibrate the relationship between the mechanical prop-erties of HFRC and temperature, a series of empirical equations are proposed. The effects of various influencing factors are considered, including fibre type, fibre shape, fibre dosage, water-binder ratio, moisture content and chemical composition. The effectiveness and accuracy of the proposed model is validated by comparing the simulation results with the test data from literature.

Automated summary

In this study, a constitutive model is developed to simulate the behavior of hybrid fiber reinforced concrete (HFRC) under fire conditions. Empirical equations are proposed to calibrate the relationship between the mechanical properties of HFRC and temperature, considering various influencing factors. The effectiveness and accuracy of the model are validated by comparing simulation results with test data.