ZHAO J, WU M X, YAO D M, et al.Study on uniaxial tensile test of grouting sleeve of seamless steel pipe after high temperature[J].Journal of Henan Polytechnic University(Natural Science) ,2024,43(4):186-196.

doi:10.16186/j.cnki.1673-9787.2023070001

Received:2023/07/01

Revised:2023/09/08

Published:2024/07/05

Study on uniaxial tensile test of grouting sleeve of seamless steel pipe after high temperature

ZHAO Jun, WU Mingxun, YAO Dunmin, MA Bin

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

Abstract:  Objectives  In order to understand the mechanical properties of the grouting sleeve of seamless steel tube after high temperature，  Methods  the uniaxial tensile test of the grouting sleeve of seamless steel tube after high temperature was carried out with temperature， cooling mode， thickness of protective layer， and diameter of steel bar as research parameters.  Results The flexural strength and compressive strength of the grouting material decrease with the increase of temperature. When the temperature reaches 800 °C and 1 000 °C， the influence on the flexural strength and compressive strength is greater. The flexural strength decreases by 59% and 81%， the compressive strength decreases by 44% and 72%， and the flexural strength decreases by more. It shows that the influence of temperature on the flexural strength of grouting material is greater than that on compressive strength. There are two failure modes of steel bar breaking and steel bar pulling out after high temperature. The critical temperature of steel bar pulling out failure of water- cooled and unprotected layer specimens is lower than that of normal temperature specimens at 800 °C. The water-cooled and unprotected layer specimens are more prone to steel bar pulling out failure. The protective layer can effectively improve the ductility and bearing capacity of the grouting sleeve. As the diameter of the steel bar increases， the ultimate bearing capacity of the joint specimens decreases. The ultimate strength of the specimens with steel bar diameters of 18， 20， and 22 mm decreases by 20.72%， 24.24%， and 25.97%， respectively. The calculation formula of bearing capacity of the grouting sleeve after high temperature is derived under the influence of various parameters. The calculation results are in good agreement with the experimental results. The formula can predict the bearing capacity of the full grouting sleeve after high temperature.  Conclusions The higher the temperature， the greater the influence on the mechanical properties of the grouting material. The water-cooled specimen is more sensitive to high temperature， and the protective layer can effectively improve the high-temperature resistance of the grouting sleeve.

Key words:fabricated building;seamless steel;pipe full grouting sleeve;monoaxial stretching