Experimental Study on Flexural Performance of Regulated Reinforced Glulam Beam after Long-Term Loading

Nan Guo,Yan Zhao,Ling Li,Chao Yang,Guodong Li

doi:10.3390/su13105556

Abstract

Due to wood creep characteristics, the failure mode, bearing capacity, stiffness, and deformation of its components are doomed to be impacted by long-term loading. This paper conducted a comparative test on creep beams, regulated beams, and short-term beams based on the former long-term loading research. The results demonstrated that the glulam beam experienced tensile failure of the beam-bottom, while the horizontal joint failure and the local compressive failure of the beam-end happened in the reinforced glulam beam and the prestressed glulam beam. The bearing capacity of the creep beams decreased compared with that of the short-term beams; the decline in the bearing capacity of the ordinary glulam beams, the reinforced glulam beams, and the prestressed glulam beams ranged from 3.2% to 9.8%, from 1.6% to 13.2%, and from 2.9% to 9.2%, respectively. However, the bearing capacity of the regulated beam with the deformation restored to the initial value of the load increased by 4.6–14.1%. The prestressed regulation changed the distribution of the stress on the beam and thus enhanced its bearing capacity. The findings of this work could be used as a frame of reference for similar components in engineering applications.

Highlights

A thread was formed at the end of the steel bar, and the prestress could be applied by tightening the screw cap at the end, thereby forming a regulated reinforced glulam beam with a simple structure and reasonable force
According to the test results, the failure types of glulam beams were classified into three types of destruction, including the tensile failure of the beam-bottom, the horizontal joint failure, and the local compressive failure of the beam-end
It should be noted that when the span-to-depth ratio was greater than 10, the glulam beam generally suffered from bending failure rather than shear failure

Summary

Introduction

It is well known that creep is one of the basic characteristics of wood, which increases the long-term deformation of wood components and reduces its strength and stiffness to a certain extent. Such characteristics can take a toll on the safety performance of structures [14,15,16,17]. Studying the flexural performance of regulated reinforced glulam beams after long-term loading has important research value and engineering significance

Methods

Results

Conclusion