Effect of the Nonprestressed/Prestressed BFRP Bar on Flexural Performance of the Bamboo Beam

Qingfang Lv,Ye Liu,Yi Ding

doi:10.1155/2019/7143023

Abstract

Until now, the systematical and comprehensive strengthening techniques have not been formed for the bamboo structure. Under such background, this paper aims to explore the effects of the application of the nonprestressed and prestressed basalt fiber-reinforced polymer (BFRP) bars on the flexural performance of the beams made of the laminated bamboo and reconstituted bamboo materials. Two series of four-point bending tests were thus conducted. In the first series of tests, the pure laminated bamboo beam and the laminated bamboo beam applied with nonprestressed BFRP bar were compared. Test results showed that the ultimate load and deformation capacity of the laminated bamboo beam was improved due to the existence of the BFRP bar. In the second series of tests, the reconstituted bamboo beams applied with nonprestressed and prestressed BFRP bars were compared. It is found that the ultimate load of the reconstituted bamboo beam was not improved by the application of the prestressed force. The further analysis related to the prestress loss demonstrated that the prestress loss before the release of the prestressed BFRP bar could reach up to 31.8–37.3% compared with the design initial prestressed stress. The prestress loss caused by the elastic deformation of the bamboo beam can be neglected. For all tested specimens, the plane section assumption was acceptable and the position of the neutral axis of the beam gradually moved down with the increase of the applied load.

Highlights

Inspired by the above studies, this paper explores the application of the ber reinforced polymer (BFRP) bar in the laminated bamboo beam and reconstituted bamboo beam
The di erence in the exural performance between the pure laminated bamboo beam and laminated bamboo beam applied with nonprestressed BFRP bar and between the reconstituted bamboo beams applied with nonprestressed BFRP bar and prestressed BFRP bar was discussed
Main conclusions are summarized as follows: (1) Based on test results of the rst series, it is found that the ultimate load of the laminated bamboo was increased by the application of the nonprestressed BFRP bar. e sti ness of the laminated bamboo beam was relatively improved in the nonlinear stage

Summary

Introduction

To utilize advantages of the raw bamboo and improve its material stability and performance, kinds of bamboo engineering material, including laminated bamboo [16, 17] and reconstituted bamboo [18, 19], have been proposed and studied, which is bene cial to reduce the material discreteness and enlarge practical applications of the bamboo [7]. Test results showed that the application of the ber-reinforced polymer can be e ective in improving the exural performance of bamboo beams. Compared with the steel and CFRP, the elastic modulus of the basalt ber reinforced polymer (BFRP) is relatively small [30], which may have a better cooperative working performance with bamboo engineering material [31].

Objectives

Methods

Conclusion