Key Engineering Materials Vol. 517

Abstract: The earthquake on 1999 in Armenia city (Colombia) showed the good seismic performance of structures using bamboo guadua as main material but also the mistakes caused by improper techniques of construction and the lack of parameters design for this type of structures. This work presents the experimental methodology used for the determination of allowable stresses for the design of bamboo guadua structures, used in the project "Validation of Guadua Angustifolia as a structural material for design, by the allowable stresses methodology" financed by the Ministry of Agriculture and Rural development of Colombia (Ministerio de Agricultura y Desarrollo Rural de Colombia) and developed by National University of Colombia (Universidad Nacional de Colombia) since the year 2008 when there were no allowable stress design standards for this structures in Colombia. For the determination of the allowable stresses were carried out tests of samples in compression, tension, and shear parallel to the fiber, compression perpendicular of the fiber and bending beams with bamboo guadua from three different areas of Colombia. It was found also the flexural elastic modulus for the material.

Abstract: t is particularly important to develop biomass briquette as alternative solid fuel for the decline of natural coal reserves. This paper focused on analysis of preliminary characteristics of briquette charcoal made from bamboo processing residues. We conducted proximate analysis including content of volatiles, fixed carbon, moisture and ash respectively; determined its density, durability and combustion characteristics. Those results will provide significantly technical parameters for utilization of bamboo waste and biomass resources as solid fuel.

Abstract: Bamboo has been known as a good substitute of engineered wood raw material in the world for its naturally oriented high strength. In this paper, we made the bamboo and poplar composite OSB (oriented strand board) with different hybrid ratios in order to understand the technical feasibility of this composite OSB and to expand the engineered utilization of bamboo. The physical and mechanical properties are tested and the effect of different hybrid ratios on physical and mechanical properties of the board was analyzed. Using this bamboo and wood mixed structure, not only are we to improve the properties of the board, but also to expand the application fields, moreover to enhance the utilization ratio of resources.

Abstract: A novel kind of parallel strand lumber (PSL) was produced, in which bamboo slivers with viscoelastic deformation were mixed with poplar veneer strands at a weight ratio of 1:4 as raw materials, then the flexural characteristics of PSL were investigated. The results showed that stretching treatment was an effective method to generate viscoelastic deformation of bamboo slivers, which would induce prestress in the bamboo slivers, reinforced PSL. The modulus of rupture (MOR) and modulus of elasticity (MOE) of prestressed bamboo slivers reinforced PSL were 7.84% and 11.76% higher than that of control PSL respectively. The flexural toughness index of prestressed bamboo slivers reinforced PSL was increased by 27.55% compared with control PSL. The presence of prestress in bamboo slivers reinforced PSL significantly enhanced its flexural stiffness and toughness, while it had no obvious effect on its flexural strength.

Abstract: This research evaluated the planing performance of bamboo scrimber boards at three feed speeds and three cutting depths and used two methods to assess the finished surfaces. A macroscopic grade assessment was made according to ASTM D 1666-87 for visible planing defects. The other assessment was a microscopic scale roughness test measuring surface average roughness in terms of GB/T 12472. The visible results showed that the finished surface quality of bamboo resulted mainly in Grades and , with the main defect being torn grain. The two evaluations method showed consistent results in surface quality that the highest percentage of Grade was counted and the lowest roughness value occurred. Compared with the hardwood Sawtooth oak widely used in furniture industry in China, planning quality of bamboo scrimber board is better in terms of roughness.

Abstract: This paper explored the influence of ultrasonic dip treatment method on bamboo fungi through comparing ultrasonic dip treatment with mold inhibitor dip treatment. Results showed that the appearance time sequencing in order was mold inhibitor dip treatment groups, ultrasonic dip treatment groups and control group. The control group had the highest mold rating. The mold ratings of ultrasonic groups were higher than the lower concentration mold inhibitor dip treatment groups and lower than the higher concentration mold inhibitor dip treatment groups.

Abstract: Considering bamboo as a 2-phase natural composite made up of vascular bundles (reinforcement or fiber) and matrixes (ground tissues) on the scale of micromechanics. By test of bamboo specimens and analysis of microscopic images of their cross sections, the distribution of vascular bundles along the axial and radial of bamboo culm were investigated. The relations between tensile properties of bamboo and its distribution of vascular bundles were studied. The results show that the vascular bundles are graded distributing along the radius of bamboo culm. The volume fraction of vascular bundles is larger near the outside, and attenuates rapidly to about 40 percent of that at the location away from outer side about 1/3 thickness of bamboo culm, and than slowly reduces to 0 near the inner side of culm. In axial direction, the volume fraction of vascular bundles in the bottom culm is smaller than that in the middle culm where the volume fraction is less variation, and reaches the largest value at the top culm. The tensile moduli and strength of bamboo are linearly related to the volume fraction of vascular bundles. The tensile moduli and the strength of vascular bundle are largely grater than that of matrix. The stiffness and the strength of bamboo are mainly offered by vascular bundles.

Abstract: Bamboo is an ancient building material, but it is rarely applied in the modern buildings nowadays. The German-Chinese House in EXPO 2010 Shanghai China is mainly made up of bamboo members; it fully demonstrates the ideas of sustainable development and environmental protection. The 8m high pavilion is a two-storey building which is 25m long and 10m wide, and its first floor is 250 m² and second floor is 80 m². The exterior structure of the pavilion is made up of 96 JULONG bamboo canes whose diameter is approximately 200mm, and the inner two storey structure is made up of glubam beams and columns which have a section of 300mmX400mm. Obviously the designer had applied both the good compression capability of the pure bamboo canes and the excellent bending capability of the glubam members in this structure. As there is no bearing capacity data of the glubam, several tests for the glubam members had been carried and thus a lot of useful data had been got, therefore some structure analysis had been done. It indicates that glubam is a good structural material, and as a friendly environmentally building material, it can be widely applied in building engineering.[

Abstract: Guadua Angustifolia Kunth (Guadua) is a tropical species of bamboo endemic to South and Central America and widely used as a mainstream material for construction in Colombia. Its rapid rate of biomass production, renewability, high level of CO₂ fixation and storage, wide diameter, long-length, and durability are distinctive and highly desirable features which can benefit the new built environment Research interest in Guadua construction increased significantly after many Guadua-constructed buildings withstood or suffered only minor damage during an earthquake which reached 6.2 on the Richter scale in 1999, resulting in the standardization of Guadua in the seismic-resistant Colombian code (NSR, 2010). However, Guadua buildings constructed in the Americas and other parts of the world, whilst considered to be sustainable, are not fully characterised in terms of the preparation, use and disposal of Guadua. Furthermore, workability, building durability and the construction process have not been specifically documented and evaluated. The structure, properties and availability of Guadua are described in this paper. A case study on a recently built holiday house is presented illustrating the architectural, structural, environmental and technical performance of a Guadua building. This paper presents the construction process, discusses difficulties encountered during the building life cycle and highlights the need for similar assessments. It is concluded that with the aim of achieving a low carbon construction system using Guadua bamboo, challenges regarding manufacture, bio-deterioration, integration with conventional systems, and environmental impacts must be addressed.

Abstract: This paper reports the first step of a study to evaluate the lateral resistance capacity of Round bamboo shear walls and its mechanical properties under Monotonic and cyclic loading conditions. The bamboo shear walls are built with round bamboo as its stub and with ply-bamboo sheet as its sheathing. Load-displacement curves of six round bamboo shear walls, with three different connection types, were obtained in this experiment, and the test results showed that the lateral resistance capacity of round bamboo shear walls can exceed 4.0kN/m, satisfying the projects requirement. A combination of nail and panel failures were observed in the test.