WANG Q, HU Z J, ZHU W X,et al.Seismic damage modeling of prefabricated columns strengthened with prestressed CFRP strips and high-strength grout after severe earthquake damage[J].Journal of Henan Polytechnic University(Natural Science) ,2026,45(5):177-187.

doi:10.16186/j.cnki.1673-9787.2024030049

Received:2024/03/18

Revised:2024/06/11

Published:2026-07-24

Seismic damage modeling of prefabricated columns strengthened with prestressed CFRP strips and high-strength grout after severe earthquake damage

Wang Qiang1,2, Hu Zhaojie2, Zhu Wanxu1,2, Lu Chunling1,2

1.Guangxi Key Laboratory of Green Building Materials and Construction Industrialization， Guilin University of Technology， Guilin  541004， Guangxi， China；2.School of Civil Engineering， Guilin University of Technology， Guilin  541004， Guangxi， China

Abstract: Objectives To quantitatively evaluate the damage state of prefabricated columns subjected to secondary seismic damage after emergency repair under earthquake actions， a seismic damage model for prefabricated reinforced concrete columns strengthened with prestressed carbon fiber-reinforced polymer （CFRP） strips and high-strength grout is developed.  Methods Four prefabricated reinforced concrete square columns were designed with axial compression ratio and longitudinal reinforcement diameter as variables. Cyclic loading tests were conducted to simulate severe seismic damage states. The damaged concrete was removed， and the columns were subsequently repaired and strengthened using prestressed CFRP strips and high-strength grout， followed by quasi-static tests. Based on existing theoretical models and experimental results， a dual-parameter seismic damage model was proposed by introducing reconstructed concrete strength and reduced shear reinforcement elastic modulus. Nonlinear regression analysis was performed on key design parameters to obtain the expression of combination coefficients， and damage quantification was carried out based on the proposed model.  Results The results show that， under a constant axial compression ratio， the damage index decreases with increasing longitudinal reinforcement diameter. Conversely， under a constant longitudinal reinforcement diameter， the damage index decreases with increasing axial compression ratio. Existing models generally yield damage indices either greater than 1.0 or lower than 0.8 for repaired columns， failing to accurately describe the damage evolution process. In contrast， the proposed model yields damage indices ranging from 0.8 to 1.0， which better reflects the damage evolution behavior of severely earthquake-damaged prefabricated columns repaired with prestressed CFRP strips.  Conclusions The proposed model effectively captures the seismic damage evolution behavior of repaired prefabricated columns under earthquake loading. Based on the model and experimental results， five damage levels are redefined with corresponding threshold values of the damage index， providing a theoretical basis for seismic damage assessment of prefabricated structural members after severe earthquake damage.

Key words:prefabricated reinforced concrete columns;prestressed CFRP strips;seismic damage repair;initial damage state;seismic damage model