Study on flexural performance of prestressed glulam continuous beams under control influence

Lidan Mei,Nan Guo,Hongliang Zuo,Ling Li,Yan Zhao

doi:10.1186/s10086-021-01980-w

Abstract

Traditional glulam beam connection mode has a weak ability to transfer bending moment, leading to insufficient joint stiffness and mostly in the form of simply supported beams. To make full use of material strength, a novel prestressed glulam continuous beam was proposed. On this basis, this paper put forward a new method to further improve the mechanical performance of the beams by controlling prestress. According to the estimated ultimate loads of the beams, six different control range values were formulated, and 12 continuous beams were tested for flexural performance. The effects of prestressing control on the failure modes, ultimate load capacity, and load versus deformation relationships of the glulam continuous beams were analyzed. The test results indicated that the flexural performance of the beams with prestressed control was significantly improved compared to the uncontrolled beams, the ultimate load was enhanced by 13.60%–45.11%, and the average steel wire stress at failure was increased from 70% of the designed tensile strength to 94%. Combined with the finite element analysis (FEA), the reasonable control range of the prestressed control continuous beams was18%–30% of the estimated ultimate load. The research in this paper can provide references for the theoretical analysis and engineering application of similar structures.

Highlights

Timber has significant advantages such as pollution-free, low energy consumption, and recyclability
As one of the prominent flexural members in timber structure buildings, the glulam beam is of great significance to the safety of the whole structure
When the glulam beam was flexural, the tensile zone of the beam would be prone to brittle failure, and its compressive strength to be not fully used [10,11,12,13,14,15]

Summary

Introduction

Timber has significant advantages such as pollution-free, low energy consumption, and recyclability. Glulam is the most common engineering wood product in timber structure, reduces the impact of natural timber defects by processing natural timber, which can improve its strength and stiffness [1,2,3,4,5,6,7,8,9]. As one of the prominent flexural members in timber structure buildings, the glulam beam is of great significance to the safety of the whole structure. Uzel et al [22] studied the flexural behaviors of glulam beams retrofitted with aluminum, fiberglass, and steel wire nets at the lamination surfaces. Yang et al [25] proposed the reinforcement method of pasting steel plates or adding screws at the bottom of the glulam beam. Results showed that the bending performance of glulam beams was improved

Objectives

Methods

Results