Evaluation of the Behavior of Carbon Short Fiber Reinforced Concrete (CSFRC) Based on a Multi-Sensory Experimental Investigation and a Numerical Multiscale Approach

Abstract

Carbon fiber reinforcement used in concrete has become a remarkable alternative to steel fibers. Admixing short fibers to fresh concrete and processing the material with a 3D printer leads to an orientation of fibers and a material with high uniaxial strength properties, which offers an economic use of fibers. To investigate its mechanical behavior, the material is subjected to flexural and tensional tests, combining several measuring techniques. Numerical analysis complements this research. Computed tomography is used with several post-processing algorithms for separating matrix and fibers. This helps to validate fiber alignment and serves as input data for numerical analysis with representative volume elements concatenating real fiber position and orientation with the three-dimensional stress tensor. Flexural and uniaxial tensional tests are performed combining multiple measuring techniques. Next to conventional displacement and strain measuring methods, sound emission analysis, in terms of quantitative event analysis and amplitude appraisal, and also high-resolution digital image correlation accompany the tests. Due to the electrical conductibility of carbon fibers, the material’s resistivity could be measured during testing. All sensors detect the material’s degradation behavior comparably, showing a strain-hardening effect, which results from multiple, yet locally restricted and distributed, microcracks arising in combination with plastic deformation.

Cyclic Deterioration of High‐performance Concrete – Findings of the Priority Programme SPP 2020

“…The mechanical behaviour of short carbon fibre-reinforced concrete subjected to tensile and bending load was investigated [30]. Orientation of the fibres in the material resulting in high uniaxial strength properties can be achieved by processing a mixture of concrete containing 1 or 3 vol% of short carbon fibres with a diameter of less than 10 μm in a three-dimensional printing manner.…”

Microstructure and Mechanical Properties of Cost-Efficient 3D Printed Concrete Reinforced with Polypropylene Fibers

“…To advance the understanding of 3D printed concrete and its behavior under various conditions, we intend to develop dedicated numerical models [41,42]. These models will facilitate in-depth analysis and simulations, enabling us to predict and optimize the performance of 3D printed structures.…”

Influence of Concrete Shrinkage on the Behavior of Carbon Short-Fiber-Reinforced Concrete (CSFRC) under Tension

“…The third application of carbon fibers in civil engineering is reinforcing concrete with short carbon fibers, hereinafter called carbon short-fiber-reinforced concrete (CSFRC). The efficiency of this type of concrete reinforcement depends on the angle between the carbon fiber direction and the stress direction and percentage of carbon fibers in the concrete mixture [11][12][13]. Fiber orientation can be directed as desired using a special technique.…”