Flexural behavior of lightweight bamboo–steel composite slabs Yushun Li a,n , Huangying Shen a , Wei Shan b , Tianshi Han a a Department of Civil Engineering, Ningbo University, Ningbo 315211, PR China b School of Civil Engineering, Northeast Forestry University, Harbin 150040, China article info Article history: Received 1 October 2010 Received in revised form 21 December 2011 Accepted 3 January 2012 Available online 28 January 2012 Keywords: Cold-formed thin-walled steel channel Bamboo plywood Composite slab Adhesive bonding Flexural behavior abstract This paper examined the potential of the lightweight bamboo–steel composite slab as a structural member. Six slab specimens were tested to study the flexural behavior of the composite slabs, which were composed of cold-formed thin-walled steel channel and bamboo plywood sheathings. Three types of connections to fabricate the composite slabs were investigated, which are simple adhesive connection, self-tapping screw enhanced connection, and stability improved connection with bamboo laths glued on the both sides of cold-formed steel channel. Results indicated that the specimens fabricated using the stability improved connection showed a remarkable increase in stiffness, capacity and stability, compared with the other two connections. The bamboo–steel composite slabs have the potential to replace concrete or wood slabs in low buildings. & 2012 Elsevier Ltd. All rights reserved. 1. Introduction Bamboo is characterized as a renewable, biodegradable and energy efficient natural resource with a great potential as a sustainable structural building material. It has high strength to weight ratio compared to conventional materials such as con- crete, timber and steel [1–5]. There are about 1250 species of bamboo in the world and 500 species in China [6]. These species will reach their maximum height, between 15 m and 30 m, within 2 months to 4 months. It takes 3 years to 8 years for bamboo to reach its maximum strength. Diameters of this plant range from 5 cm to 15 cm [7]. The species most commonly cultivated for structural use are moso (Phyllostachys pubescens), known as mao zhu in China, and Guadia (Guadia angustifolis), native to South America [8]. The bamboo plywood used in this study is made from the moso bamboo. The moso bamboo grows fast and it has large stem diameter and long stalk. Generally speaking, the moso bamboo can be used for engineering purposes after 3–5 years’ growth. The moso bamboo covers almost 70% of the total area where the bamboo grows in China. In addition, 85% of the world’s moso bamboo grows in China [9]. Moso bamboo has great strength, flexibility and versatility, but it has just been used in rural housing or for construction purposes, for example scaffold- ing in Asia and South America [10]. Wide applications of bamboo in civil engineering were limited by its dimensional instability due to the moisture, inadequate adhesive bonding, difficult connections due to its irregular shape, inadequate knowledge of modern bamboo structure design, and lack of official design codes and standards. Many researchers have devoted themselves to develop bamboo and bamboo products as new modern structural building materials. Bamboo reinforced concrete has a long history of research and applications in civil engineering [11,12]. Other researchers developed many composite materials with superior mechanical properties utilizing bamboo fibers [13,14]. In recent years, some research work has been carried out to develop a laminated bamboo lumber using adhesive to join bamboo strands or flattened surfaces taken from the bamboo culm (i.e., bamboo stem) [7]. In addition, some researchers developed new structural systems using laminated bamboo panel to construct small bridges and low-rise buildings [15,16]. The construction methods are similar to the modern wood structures in many industrialized countries. At the same time, with the development of structural adhesives, they are widely applied to civil engineering [17,18]. And these adhesives can be applied to fabricate bamboo compo- site structural members. A lot of researches have been completed at the Ningbo University to promote the application of the laminated bamboo panel since 2005 [19–23]. A new bamboo–steel composite struc- tural system is under investigation. Various bamboo composite members, such as composite slabs, walls, beams, and columns, are used to build beam–column frame structures or to assemble large-scale panel structures with rigid connection or other reli- able connections. These composite members are fabricated by cold-formed thin-walled steel and laminated bamboo panels bonded by the adhesive or the hybrid adhesive–screw joins [19–23]. Contents lists available at SciVerse ScienceDirect journal homepage: www.elsevier.com/locate/tws Thin-Walled Structures 0263-8231/$ - see front matter & 2012 Elsevier Ltd. All rights reserved. doi:10.1016/j.tws.2012.01.001 n Corresponding author. Tel.: þ86 574 87609512; fax: þ86 574 87600328. E-mail address: lys0451@163.com (Y. Li). Thin-Walled Structures 53 (2012) 83–90