Experimental Study on the Seismic Behaviour of Reinforced Concrete Bridge Piers Strengthened by BFRP Sheets

Yong Li,Jing-Bo Liu,Meng-Fei Xie

doi:10.1155/2019/4169421

Abstract

With the continuous development of the ductility capacity concept for seismic design of bridges, the ductility capacity of many existing bridges does not meet the requirements of the current code for seismic performance because of the low reinforcement ratio and reinforcement corrosion of reinforced concrete (RC) piers. Because of their superior mechanical properties and low price, basalt fibre-reinforced polymer (BFRP) sheets have potential application in the seismic retrofits field of existing bridges. To study the seismic strengthening effect of RC pier columns, scaled specimens with standard reinforcement ratios, with low reinforcement ratios according to the past code and with corroded reinforcements, were designed and manufactured and then wrapped and pasted with BFRP sheets on the plastic hinge areas. Pseudostatic tests were conducted to verify the seismic performance of the strengthened and unstrengthened specimens. Experimental results showed that the ultimate flexural capacity, deformation capacity, and energy dissipation capacity of strengthened RC pier columns were superior. Especially for strengthened specimens with low reinforcement ratios or corrosion reinforcement, their seismic performance could rival than that of columns with standard reinforcement ratios, which showed the advantage of BFRP sheets in the seismic retrofitting of existing bridge piers.

Highlights

Bridge damage in earthquakes leads to traffic interruption and economic losses [1]
Lu et al [15,16,17] conducted a study on the seismic performance of earthquake-damaged concrete frame joints reinforced by basalt fibre-reinforced polymer (BFRP) sheets. e results showed that the seismic performance of strengthened joints was greatly improved, and all 3-dimensional reinforced concrete frame joints strengthened by BFRP sheets achieved the design object of strong-column and weak-beam
Because there is less research on BFRP sheets used in seismic strengthening of viaduct piers, quasistatic loading tests of 1 : 5 scaled pier columns were conducted under low-cycle reciprocating loading to obtain the hysteresis performance curve, and stiffness, flexural capacity, equivalent viscous damping coefficient, and energy dissipation parameters were analysed to reveal the improvement efficiency of BFRP sheets in seismic strengthening

Summary

Introduction

Bridge damage in earthquakes leads to traffic interruption and economic losses [1]. At present, there are a large number of viaducts designed according to the elastic seismic design method adopted by the previous seismic design code for highway bridges [2]. Lu et al [15,16,17] conducted a study on the seismic performance of earthquake-damaged concrete frame joints reinforced by BFRP sheets. E results showed that the seismic performance of strengthened joints was greatly improved, and all 3-dimensional reinforced concrete frame joints strengthened by BFRP sheets achieved the design object of strong-column and weak-beam. Because there is less research on BFRP sheets used in seismic strengthening of viaduct piers, quasistatic loading tests of 1 : 5 scaled pier columns were conducted under low-cycle reciprocating loading to obtain the hysteresis performance curve, and stiffness, flexural capacity, equivalent viscous damping coefficient, and energy dissipation parameters were analysed to reveal the improvement efficiency of BFRP sheets in seismic strengthening

Experimental Design

Experimental Results

Conclusions