International Journal of Advances in Engineering & Technology, Nov., 2014.
©IJAET ISSN: 22311963
1531 Vol. 7, Issue 5, pp. 1531-1538
FLEXURAL STRENGTH OF LAMINATED BAMBOO BEAMS
James Kariuki
1
, Richard A. Shuaibu
1
*, Timothy Nyomboi
2
and Siphila Mumenya
3
1
Department of Civil Engineering, Pan African University, Institute for Basic Science,
Technology and Innovation (PAUISTI), JKUAT, Kenya
2
Department of Civil and Structural Engineering, Moi University, Kenya
3
Department of Civil and Construction Engineering, University of Nairobi, Kenya
ABSTRACT
The need to discover new and sustainable building materials has necessitated research in different parts of the
world. This study presents a comparative performance of bamboo laminated beams with cypress beams of the
same dimensions. Six laminated bamboo beams and three cypress beams were tested in this study. The dimensions
of each specimen was 45mm x 95mm x 600mm and tested under two point loading. Experimental results revealed
that bamboo laminated beams resisted higher load than cypress beams and had a higher flexural strength of
39kN/mm2 against that of cypress beam of 34kN/mm2. Also, while cypress beams failed in flexure with major
cracks, bamboo laminated beams however failed in tension on the lower part of the beams and shear along the
grains. In addition, it was observed that bamboo laminated beams took longer duration than cypress beam to fail
completely. The study hereby concluded that bamboo laminated beams showed better load carrying capacity than
cypress beams.
K EYWORDS: Bamboo, Cypress, Lamination, Beams, adhesive, failure pattern
I. INTRODUCTION
In recent times, it has become more and more essential to discover opportunities for new and sustainable
building materials due to drop in level of resource availability [1]. Some factors however influence the
choice of building materials. These factors include price, appropriateness and design knowledge of
those materials. Issues such as renewability of resources, energy efficiency and eco-friendliness are also
becoming progressively vital. Studies have shown that bamboo in comparison to timber, which takes
years, have the benefit of been harvested in 3-4 years from the time of plantation [2,3]. The anatomy of
bamboo internode cross-section also revealed that the strength properties of bamboo increase from inner
to outer layer of the culm [4]. Bamboo has been used in various forms to determine its suitability as a
construction material. For instance, the potential of bamboo as reinforcement in concrete was
investigated by [5] and found that if bamboo reinforced concrete beam is reinforced with steel stirrups,
it improves its load carrying capacity. On the other hand, different studies have characterised bamboo
composites based on bamboo fibres in polymeric matrix [6] [7] [8] [9]. Recently, [10] arranged bamboo
stripes in different orientations and investigated the effects of orientation on strength of laminated
bamboo beams. Their observations showed that, for face loaded beams, the elasticity had a decreasing
influence on longitudinal tensile strength. However, the flexural strength of the beams were found to
improve while loaded on the face and edges. Another study conducted by [11] established that
laminated bamboo possess greater allowable and average strength values in flexure and tension and
comparable stiffness values, with much less variability to a commonly used structural species of wood,
Douglas fir. They also affirmed that, it is possible to use laminated bamboo in framing applications.
This material can be utilized as structural members such as structural beams, roof structures and curtain
walls as shown in Figure 1.