Temperature effect on the tensile constitutive parameters of fiber reinforced concrete

This paper focuses on the effect of moderate temperature variations on the flexural behavior of polypropylene macro-synthetic fiber reinforced concrete. A comprehensive study has been carried out to investigate the influence of temperature on the tensile constitutive parameters. The study is based on the results of an experimental campaign consisting of compression tests and three point bending tests conducted on specimens cured at different temperatures, ranging from -30 ° C to 60 ° C . The core of the research is the calibration of the relationship between the constitutive parameters for polypropylene macro-synthetic fiber reinforced concrete and temperature values. A hybrid regression model is developed to describe the relationship and the most adequate regression model is selected among several alternatives according to the Akaike Information Criterion. It involves a bi-linear relationship between each one of the constitutive parameters and temperature, with a common transition temperature for the parameters mostly related to the post-cracking behavior. This model proves to be well suited to describe the temperature effect for different polypropylene macro-synthetic fiber reinforced concretes and it provides valuable insights for structural applications. The paper also presents the procedure for the estimation of the hybrid regression model, which can be adopted for modeling the temperature effect on fiber reinforced concretes constituted by materials of different properties.