Study on the effectiveness of fibre reinforcement on the engineering performance of foamed concrete

Mechanical properties, workability and pore structures of foamed concrete (FC) reinforced with different fibres were investigated. In order to characterise the cementitious matrix with entrained bubbles and fibres, X-ray computed tomography (X-CT) technology and Digital image correlation (DIC) technique were employed to analyse the pore structure and the real-time strain field distributions under applied loads, respectively. The results demonstrated that the inherent properties of fibres, including density, modulus and wettability, and bond performance between the cement matrix and fibres are two main factors in determining the mechanical properties of the fibre reinforced FC. Meanwhile, the fibres also had an influence on the workability and rheological properties of fresh FC slurry through changing the bubble numbers and distributions in the slurry. According to the strain analysis during the bending tests using the DIC technique, it was found that carbon fibre and polyacrylonitrile fibre were conducive to distributing the strain field in the FC in a homogeneous fashion and delayed crack widening after the peak loads effectively.