GLUED LAMINATED BAMBOO BEAM

Description

FIELD OF THE INVENTION

The present invention relates to a building material, and more particularly to a glued laminated bamboo beam.

BACKGROUND OF THE INVENTION

In order to ameliorate the problems of global warming and climate extremes, energy saving and carbon reduction have become a global concern. In particular, the construction industry which has a high carbon footprint has begun to place more emphasis on green materials in recent years.

Bamboo is a low-carbon and recyclable green material, and it grows quickly, about four to six years, much shorter than the time needed for forest trees to grow, making it very economical and environmentally friendly. Therefore, many architects at home and abroad are trying to utilize bamboo in large-scale permanent buildings. The type of joining has been developed from the initial lashing system to the use of joining components of different materials for joining, such as pin-type joining, intermediary component joining, integrated joining, axial continuation joining, and the like. However, due to the climate and growing environment, the naturally grown bamboo is not easy to be used because of its variable size, curvature and irregular shape.

In recent years, with the advancement of processing machinery and gluing technology, bamboo craft development technology in Taiwan is mature. Laminated bamboo is developed on the market. It is a technology that makes bamboo from cylindrical bamboo into standardized bamboo sheets and glues bamboo sheets into plywood. This solves the problem that natural bamboo material is not easy to be standardized. Currently, laminated bamboo is widely used in furniture, but it has not yet been used as a building material. If its strength and structural stability can be further improved, it will be more suitable to be used as a building material for large-scale permanent buildings.

SUMMARY OF THE INVENTION

In order to make bamboo more suitable for use as a building material for large-scale permanent buildings, the primary object of the present invention is to provide a glued laminated bamboo beam. The glued laminated bamboo beam comprises a plurality of bamboo strips. The bamboo strips are glued to form a structural element having at least one laminated bamboo layer. The bamboo strips each have a plurality of nodes. The nodes of the bamboo strips are at least partially staggered or/and are staggered from a middle portion of the structural element, thereby improving strength and enabling the structure of the structural element more stable.

Preferably, the structural element includes a web and at least one or two flanges connected to the web to form an I-shaped or H-shaped structural element by snapping or/and gluing. Alternatively, the structural element may be formed into a cylindrical structural element by heating and humidifying.

Preferably, the web or/and the flange include a plurality of laminated bamboo layers.

Preferably, the web or/and the flange include at least three laminated bamboo layers. Each laminated bamboo layer defines an arrangement direction along a direction of the bamboo strips to be arranged. The arrangement direction of one of the laminated bamboo layers is different from the arrangement direction of an adjacent one of the laminated bamboo layers.

Alternatively, the bamboo strips each have wider sides. The wider sides of the bamboo strips of the flange are arranged and glued in sequence.

The present invention further provides a method for manufacturing a glued laminated bamboo beam. The method comprises the following steps: arranging, arranging a plurality of bamboo strips in sequence to form a structural element having at least one laminated bamboo layer, wherein the bamboo strips each have a plurality of nodes, and the nodes of the bamboo strips are at least partially staggered or/and are staggered from a middle portion of the structural element; gluing, gluing the plurality of bamboo strips.

With the above technical features, the present invention can achieve the following effects:

• • 1. The use of laminated bamboo having standardized bamboo strips to manufacture a structural element can solve the problem that in the past, the use of natural bamboo material was not easy to be standardized due to the limitations of size variation, curvature and irregular shape.
  • 2. The nodes of the bamboo strips are at least partially staggered or/and are staggered from a middle portion of the structural element, thereby improving structural strength. The structure of the structural element is more even and stable, making it suitable for use as a building material for large-scale permanent buildings.
  • 3. The structural element made of laminated bamboo can be easily made into a T-shaped, H-shaped or cylindrical structural element.
  • 4. The web or/and the flange of the T-shaped or H-shaped structural element may include a plurality of laminated bamboo layers, and the laminated bamboo layers each include the plurality of bamboo strips that are arranged and glued in sequence, thereby improving the thickness and strength of the structural element.
  • 5. The arrangement direction of the bamboo strips of one of the laminated bamboo layers is different from the arrangement direction of the bamboo strips of an adjacent one of the laminated bamboo layers, further improving the strength of the structural element. The structure of the structural element is more even and stable.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view according to a first embodiment of the present invention;

FIG. 2 is a side view according to the first embodiment of the present invention;

FIG. 3 is a planar exploded view according to the first embodiment of the present invention;

FIG. 4 is an exploded view of the web according to the first embodiment of the present invention;

FIG. 5 is a perspective view of the web according to the first embodiment of the present invention;

FIG. 6 is an exploded view of another example of the laminated bamboo layers of the present invention;

FIG. 7 is a perspective view of another example of the laminated bamboo layers of the present invention;

FIG. 8 is a perspective view according to a second embodiment of the present invention;

FIG. 9 is a planar view according to a third embodiment of the present invention;

FIG. 10 is a schematic view showing that the bamboo strips are vertically arranged and glued in sequence; and

FIG. 11 is a schematic view of the curved structural elements of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings. It should be noted that, for case of understanding, similar or identical component symbols will be used for similar functional components in each drawing.

The present invention discloses a glued laminated bamboo beam and a method of manufacturing the same. FIG. 1 illustrates a glued laminated bamboo beam according to a first embodiment of the present invention, which is an application of an H-shaped beam as a structural element (100). The structural element (100) comprises a web (1) and two flanges (2) connected to both ends of the web (1). The web (1) and the flanges (2) each include a plurality of laminated bamboo layers (10) (20). Each laminated bamboo layer (10) (20) includes a plurality of bamboo strips (101) (201) that are arranged and glued in sequence. The web (1) and the flanges (2) each include three laminated bamboo layers (10) (20), but not limited thereto. The web (1) and the flanges (2) each may include two or more than three laminated bamboo layers (10) (20).

Referring to FIG. 2, the bamboo strips (101) (201) each have a plurality of nodes (101A) (201A). The nodes (101A) (201A) of the bamboo strips (101) (201) are at least partially staggered so that the distribution of the nodes (101A) (201A) of the laminated bamboo layers (10) (20) is more dispersed, which prevents the laminated bamboo layers (10) (20) from being damaged in the same place and makes the overall structure close to a homogeneous material. At least one portion of the nodes (101A) (201A) may be staggered from a middle portion (M) of the structural element (100), so that the more vulnerable portion may be staggered from where the load is relatively greatest.

Referring to FIG. 3 in conjunction with FIG. 1, the flanges (2) each have a connecting groove (21). The connecting grooves (21) of the two flanges (2) face each other. The depth of the connecting groove (21) is approximately half the thickness of the flange (2). The groove (21) may be a vertical groove for easy machining and assembly. Both ends of the web (1) each have a connecting portion (11). The connecting portions (11) at both ends of the web (1) are connected to the connecting grooves (21) of the two flanges (2). The web (1) has an overflow portion (12) adjacent to the connecting portion (11). Both the connecting portion (11) and the overflow portion (12) are coated with an adhesive (A), i.e., through a slight overflow of adhesive, the web (1) and the wing (2) are not easy to break and disintegrate directly in case of displacement. The adhesive (A) may be, for example, water-based emulsion glue for wood working.

Referring to FIG. 4 and FIG. 5, in this embodiment, the structures of the laminated bamboo layers of the wings and the web are substantially the same. For the sake of simplicity, the following is an example of the laminated bamboo layers (10) of the web (1) to further illustrate the detailed structure. The web (1) includes three laminated bamboo layers (10). Each laminated bamboo layer (10) includes a plurality of bamboo strips (101) that are arranged and glued in sequence. Each laminated bamboo layer (10) defines an arrangement direction (L1) (L2) (L3) along the direction of the bamboo strips to be arranged. The arrangement direction (L1) (L3) of one of the laminated bamboo layers (10) is different from the arrangement direction (L2) of the adjacent laminated bamboo layer (10). The alignment directions (L1) (L3) of the two outer laminated bamboo layers (10) may be the same, and the alignment direction (L2) of the middle laminated bamboo layer (10) may be different. Different arrangement directions (L1) (L2) are, for example, at 90 degrees, but not limited thereto. For example, they may be at various angles, such as 45 degrees, 30 degrees, 15 degrees, etc. The staggered structural design enables the structural strength to be distributed more evenly. The bamboo strips (101) of the laminated bamboo layer (10) have the same length and are arranged and glued in sequence, but no limited thereto. As shown in FIG. 6 and FIG. 7, the bamboo strips (101) of each laminated bamboo layer (10) may have different lengths.

The method of manufacturing bamboo strips includes the following steps:

• • 1. Harvesting: mature Phyllostachys edulis bamboo poles are harvested, typically at least four 4 years of age.
  • 2. Splitting: a splitting machine is used to split the bamboo poles into bamboo slats having the same width and length.
  • 3. Rough planing: the inner and outer nodes of the bamboo slats are planed to make the bamboo slats smooth and flat.
  • 4. Boiling: the bamboo slats are boiled in water to remove sugars and starches and prevent insect infestation. Hydroxide, hydrogen peroxide, insecticide, etc. can be added to the water.
  • 5. Carbonization: a carbonization furnace can be used for high temperature and high pressure treatment to remove starches and sugars and prevent insect infestation. The color of the bamboo slats will become darker after carbonization. The carbonization time may be about 40 minutes to 50 minutes, and the step of carbonization can be done once or more than twice.
  • 6. Drying: the bamboo slats are dried to reduce moisture content, and the moisture content of the finished product is kept at about 10% to 12%.
  • 7. Fine planing: the bamboo slats are polished to form bamboo strips. The surface of the bamboo strip is glossy and the thickness of the bamboo strip is uniform.
  • 8. Applying glue: after the bamboo strips are arranged in sequence, they are coated with glue, such as polyurethane (PU) for bonding.
  • 9. Gluing and hot pressing: the bamboo strips are glued and hot pressed using a hot press machine.

FIG. 8 illustrates a glued laminated bamboo beam according to a second embodiment of the present invention, which is an application of an H-shaped beam as a structural element. The structural element comprises a web (1A) and two flanges (2A) connected to both ends of the web (1A). The main difference between the first embodiment and the second embodiment is that the bamboo strips (201) of the flange (2) in the first embodiment are arranged horizontally and the bamboo strips (201A) of the flange (2A) in second embodiment are arranged vertically. That is, in the second embodiment, the bamboo strips (201A) each have wider sides (202A). The wider sides (202A) of the bamboo strips (201A) are arranged and glued in sequence. The flange (2A) in the second embodiment may be a single-layer structure.

The mechanical performance data of the above-mentioned first and second embodiments are shown in Table 1:

FIG. 9 illustrates a glued laminated bamboo beam according to a third embodiment of the present invention, which is an application of a hollow cylindrical beam as a structural element including a plurality of bamboo strips (301B) that are arranged and glued in sequence along a circumferential direction.

Referring to FIG. 10 and FIG. 11, the bamboo strips (301A) each have wider sides (302A). The wider sides (302A) of the bamboo strips (301A) are arranged and glued in sequence. Two rows of the glued bamboo strips (301B) are bent and shaped by heating and humidifying to form two curved structural elements (200B). The two curved structural elements (200B) are bonded together to form a cylindrical structural element.

Although particular embodiments of the present invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the present invention. Accordingly, the present invention is not to be limited except as by the appended claims.