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(西南交通大学 土木工程学院，四川 成都 610031)
Experiment of Fracture Performance of Fiber Reinforced Geopolymer Concrete
(School of Civil Eng., Southwest Jiaotong Univ., Chengdu 610031, China)

Abstract:To study the influence of various fibers on the fracture behavior of fly ash based geopolymer concrete (GPC), the three-point bending test of the notched concrete beam was carried out. The effects of the volume fraction of basalt fiber (BF), polyethylene-based polypropylene fiber (SPPF), and end steel fiber (SF) on the fracture properties of GPC were investigated, respectively. The results showed that: 1) The compressive strength and splitting tensile strength of BFGPC, SPPFGPC, and SFGPC were significantly improved compared with GPC. The maximum compressive strength was obtained at the volume rate of 0.2%BF, 0.8%SPPF, and 1.0%SF, respectively. The optimal volume rate corresponding to the splitting tensile strength was 0.2%BF, 0.4%SPPF, and 1.0%SF, respectively. 2) The fracture parameters of BFGPC first increased and then decreased with the increase of BF volume ratio, and the optimum dosage was 0.2%. Nonetheless, BFGPC exhibited brittle fracture characterized by BF tensile fracture. 3) In the low dosage range, the fracture parameters of SPPFGPC increased with the increase of fiber volume rate; In the high dosage range, the fracture parameters of SPPFGPC first increased and then decreased, and the optimal dosage was 1.5%; SPPFGPC failed with debonding and pull-out of SPPF. 4) As the volume ratio of SF increases, the fracture mechanical parameters and fracture energy of SFGPC gradually increased. SFGPC had significant ductile failure characteristics, and the recommended volume ratio of SFGPC was 0.5%～1.5%. 5) In the GPC system, SF enhancement and toughening effect are the best, BF enhancement is better than that of SPPF, but SPPF toughening is better than that of BF.

YANG Shiyu,ZHAO Renda,GUO Qiuyu,ZENG Xianshuai.Experiment of Fracture Performance of Fiber Reinforced Geopolymer Concrete[J].Advanced Engineering Sciences,2022,54(6):230-237.