Assessing recycling potential of carbon fiber reinforced plastic waste in production of eco-efficient cement-based materials

Abstract

The improper management and disposal of carbon fiber reinforced plastic (CFRP) waste to landfill or incineration can cause serious environmental implications. In recent years, efforts have been made to utilize recycled carbon fibers (rCFs) into the cement composites. However, no information is available on the environmental impacts of utilizing rCFs into the cement composites. In this study, efforts were made to assess the resourceful recycling of this waste to cement-based materials and to investigate the effects of recycled carbon fibers (rCFs) as reinforcement on the mechanical performance and environmental impacts of cement composites. Moreover, in-use stocks of carbon fiber reinforced plastic (CFRP) in commercial aeronautical and wind power sectors of China were calculated to estimate the prospective CFRP waste available in China for recycling. The experimental results resolved that the addition of rCFs to cement composites can provide significant improvement in mechanical performance. Among other notable results, cement composite reinforced with 1% by volume of rCFs showed optimum performance with an increase in elastic modulus, splitting tensile strength, and fracture toughness of up to 57%, 188%, and 325%, respectively. Environmental impact assessment revealed that the addition of 1% of rCFs while replacing 10% of cement with silica fume, the overall global warming potential (GWP) in terms of CO2 emissions, comes out to be 13.69% less than plain cement paste GWP impact. On the other hand, 222% of energy consumption and 70% of the cost can be saved by replacing the virgin carbon fibers (vCFs) with rCFs into the cement composites. Estimation of in-use stocks of CFRP highlighted that about 97000 Tons of CFRP waste would be cumulated into the landfills of China by the year 2044 that can be recycled to recover carbon fibers to effectively utilize them in the production of eco-friendly cement composites.