Long-term behavior of connections for glubam-concrete composite beams

Qian Yue,M Ashraf,I Corbi,L Wang,H Li,Bo Shan,Zhenyu Wang,O Corbi,P Yang,Xin Ye

doi:10.1051/matecconf/201927501001

Abstract

Glubam-concrete composite (BCC) structure is a construction technique where glue-laminated bamboo beam is connected to an upper concrete slab using different types of connectors. The long-term behavior and creep mechanism of BCC system are very complex due to different time-dependent behavior of three components. This paper performed a series long-term push-out tests on four types of connections under static load. The tests lasted for a period of seven months in uncontrolled sheltered indoor condition. Important results such as the relative slip-time curves are presented in order to characterize time-dependent behavior of connectors. Furthermore creep coefficient constitutive models are provided for predicting the long-term behavior of connections.

Highlights

IntroductionA new type of glue-laminated bamboo, was developed by Xiao et al [1]. Through designing with special laminate structure of bamboo fibers, glubam exhibits relatively higher mechanical properties compared with typical engineered lumber product, glulam (Fig.1) [2, 3]
Glubam, a new type of glue-laminated bamboo, was developed by Xiao et al [1]
This paper reports the results of an experimental program on testing these four types of connection systems

Summary

Introduction

A new type of glue-laminated bamboo, was developed by Xiao et al [1]. Through designing with special laminate structure of bamboo fibers, glubam exhibits relatively higher mechanical properties compared with typical engineered lumber product, glulam (Fig.1) [2, 3]. In-plane longitudinal compressive strength (MPa) 51 must be checked for ultimate (ULS) and serviceability limit states (SLS) at the same time. The former requires all components to meet the requirements of strength and stiffness, while the latter is mainly controlled by the maximum deflection of the structure. Some long-term studies already confirmed that the long-term deflection of timber-concrete composite (TCC) beams is significant and difficult to accurate prediction, because different time-dependent behavior of the three components such as creep of timber, shrinkage of concrete, and relatively slip of connection under long-term load [8,9,10,11]. The paper provided basic data for evaluating and predicting the long-term performance of BCC connections

Materials and test specimens

Test setup

Experimental results

Conclusions