ZHU C X, QI Z H, WU D Z. Study on macro and micro mechanical properties of carbon fiber grouting test block [J].Journal of Henan Polytechnic University(Natural Science Edition ),doi:10.16186/j.cnki.1673-9787.2023120007.

doi:10.16186/j.cnki.1673-9787.2023120007

Received：2023-12-05

Revised：2024-02-22

Online：2024-03-05

Study on macro and meso mechanical properties of carbon fiber toughened grouting body test block

ZHU Changxing,QI Zhonghua,WU Dazhi

(School of Civil Engineering, Henan Polytechnic University, Jiaozuo 454000, Henan, China)

Abstract: Objective In order to study toughness and crack resistance of carbon fiber (CF) in grouting sample (GCB). Methods three-point bending tests of 0 %, 0.5 %, 1 % and 1.5 % CF sample were carried out respectively, and the toughness and crack resistance of CF were investigated by scanning electron microscopy (SEM). Based on three-point bending numerical simulation test of 0 % and 1 % CF sample, the toughness and crack resistance mechanism of CF sample were studied by from multiple scales (meso-macro) and multiple angles. Results The 1 % CF-GCB has the best tensile strength, toughness index and energy dissipation performance. The failure modes of CF in the matrix are debonding failure, tensile failure and shear failure. The tensile failure surface is smooth and flat, and shear failure surface is 45 °oblique section. The failure mode and stress-strain curve of the laboratory test and simulation test are basically the same. The tensile strength of 1 % CF-GCB is up to 5.54 MPa, which is 18 % higher than that of 0 % CF. Conclusion The CF stress of the model bottom is higher than that the middle and model upper, and randomly distributed carbon fiber and gravel affect the crack propagation path. The research results can provide a reference for the further study of the toughness and crack resistance mechanism of carbon fiber.

Key words: carbon fiber; grouting stone body; toughening crack resistance; numerical simulation