6 / 2022-02-27 20:21:55

Mechanical properties of recycled carbon fiber reinforced cementitious matrix composites

Mechanical properties, Recycled carbon fiber, Recycled carbon fiber reinforced cementitious matrix, Virgin carbon fiber reinforced cementitious matrix.

The extensive application of carbon fiber reinforced plastic (CFRP) has generated a large amount of waste, which causes serious environmental problems. Meanwhile, the carbon fiber (CF) in the waste still maintains excellent material properties and has an extremely high utilization value. Thus, a lot of research has been carried out on the recycling of CF from CFRP waste. However, compared with virgin carbon fiber (vCF), the performance of recycled carbon fiber (rCF) is usually seriously reduced, so the reuse way is limited to remanufacturing the mixed products of resin-fiber with low mechanical properties. In the few studies on the use of recycled carbon fiber reinforced cementitious matrix, the reinforcement effect is not great since the rCF contains resin and its performance is slightly poor; besides, there is no complete comparison with the vCF. All these restrict the reuse of rCF. In this paper, the rCF without resin and non-destructive performance was used to reinforce cementitious matrix. The effects of rCF with five contents and four lengths on the mechanical properties of cementitious matrix composites were studied by the tests of fluidity, compressive strength, flexural strength and splitting tensile strength, and compared with that of vCF. The results show that the fluidity of recycled carbon fiber reinforced cementitious matrix decreases slightly, but the mechanical properties are greatly improved. Under the optimal conditions, the compressive strength, flexural strength and splitting tensile strength of recycled carbon fiber reinforced cementitious matrix are increased by 18.1% 19.1% and 44.3%, respectively. Compared with vCF, the recycled carbon fiber is slightly better in general. Due to its excellent performance, rCF was applied to reinforced cementitious matrix, which not only achieves a good reinforcement effect, but also has advantages in cost, which is conducive to the construction of closed-loop recycling and reusing of CFRP waste.