Comparative Analysis of Creep in Standard and Fibre Reinforced Concretes under different Load Conditions

Abstract

The paper presents comparison of creep measurments in normal concrete and concrete modified with dispersed reinforcement - polypropylene and steel fibres (FRC). The tests were performed for two levels of applied load: 40% and 80% of the destructive load at the load time, respectively, at 1, 4, 7 and 28 days. The resulting creep strain was compared with the calculating method from Eurocode 2, and Pre-norm Fib 2010. Significant differences in the results of the creep calculated based on the Code and measured in the research were noticed. It was also shown that the creep of FRC has different development compared to the normal concrete especially under early-age load. The value of proposed creep factor for young concrete calculated based on study results was few times higher than calculated based on the Code. The creep strain of fibre reinforced concrete loaded at the age of 24hours was, moreover much higher than of concrete without fibres. The paper illustrated differences in the dynamics and final values of creep deformation of normal concrete and fibre reinforcement concrete.