CHEN X Q, LI H M, WANG S, et al． Analysis of mine pressure behavior characteristics in the period of gateway excavation of variable width coal pillar in fully mechanized caving face in extra-thick coal seam［J］. Journal of Henan Polytechnic University( Natural Science)， doi: 10.16186/j.cnki.1673-9787.（ 2024070042  ）.

doi: 10.16186/j.cnki.1673-9787.（ 2024070042  ）

Received： 2024-07-09

Revised： 2024-08-29

Online： 2026-06-05

Study on compressive constitutive relation of sleeve grouting material for steel bar connection (Online)

Zhao Jun1，Shen Liping1，Yao Dunmin1，Liu Qizhou2

1. School of Architecture and Transportation Engineering, Guilin University of Electronic Technology, Guilin 541004, China ; 2. College of Civil Engineering, Guilin university of technology, Guilin 541004, China

Abstract: Objectives To explore the compressive properties of sleeve grouting materials used in steel bar connections, the law of changes in their compressive behavior with age, and their compressive constitutive relationship. Methods Compression tests and finite element analysis were carried out on grouting material specimens of different ages and shapes. Results The results show that the strength of the standard test block at the age of 3 days has reached 70% of the strength of 28 days. The strength of the cylindrical specimens at the same age reached 63% of the 28-day strength. It can be seen that the strength of both the standard test block and the cylindrical test block increases extremely rapidly within 3 days. However, as the age increased from 3 days to 28 days, the strength growth rate of the specimens slowed down significantly, and the final strength only increased by about 30% compared to 3 days. The stress-strain curve obtained through the axial compression test can well reflect the stress-strain relationship of the grouting material as it ages. There is a significant difference between the peak stress and the strength of the standard test block. The elastic modulus gradually increases with age. Meanwhile, the peak strain increases particularly rapidly in the early stage of the grouting material. Based on the measured stress-strain values, the fitting constitutive and statistical damage constitutive models of the grouting material were established. The established constitutive model was simulated and analyzed using finite element software. The simulation results (load-displacement curve, peak stress, and damage distribution inside the grouting material, etc.) are highly consistent with the actual test results, thus verifying the feasibility and reliability of the established constitutive model.Conclusion The experiment revealed the law of the change of the compressive properties of sleeve grouting materials with age.And by constructing and verifying reliable constitutive models, it provides important theoretical foundation and practical guidance for the design, numerical simulation, application and optimization of grouting materials in steel bar connection projects.

Key words: sleeve grouting material; compressive strength; constitutive model; stress-strain curve; finite element simulation