Macro-synthetic fibre reinforced concrete: Creep and creep mechanisms

Abstract

The creep of cracked macro-synthetic fibre reinforced concrete has been investigated in uniaxial tension at five stress levels (30, 40, 50, 60 and 70%) of the residual uniaxial tensile strength under controlled temperature and relative humidity of 23 ± 1 °C and 65 ± 5% respectively. Specimens were prepared and cracked before they were subjected to the various stress levels. One mix design has been used throughout the investigation and the fibre was used at a volume of 1%. Test results of the investigation has revealed that while the creep response is a function of the applied stress level, significant creep has been recorded after 8 months even at lower stress levels. The mechanism responsible for the time-dependent crack opening of macro-synthetic fibre reinforced concrete was investigated through time-dependent fibre pull-out and fibre creep tests. The result of this investigation has shown that macro-synthetic fibre creep and the time-dependent fibre pull-out are mechanisms responsible for the creep of cracked macro-synthetic fibre reinforced concrete.