Bamboo, a tree-like woody grass with about 1 250 species in 75 genera, is thought to have made its appearance about 200 million years ago. The plant now occurs in the tropical, subtropical and temperate zones of all regions except Europe and western Asia . Recent findings have revealed that bamboo was prevalent even in Europe some 3 million years ago but vanished some time during the last ice age.

Bamboo is perhaps the fastest-growing plant on earth, gaining approximately 75 to 400 mm per day (the record of 1.2 in 24 hours belongs to Phyllostachys edulis in Japan ). It grows three times faster than most eucalyptus species and can be bar-vested four times as often. Commercially important species usually mature in four to five years. Multiple harvests are subsequently possible every second year, for up to 120 years In some species and indefinitely in others. Bamboo is also foremost in biomass production, giving up to 40 tonnes per hectare per year in managed stands. It is estimated that about one-quarter of the biomass in tropical regions and one-fifth in subtropical regions comes from bamboo.

It is thought that about half of the world's population of more than 5 000 million shares to some extent in the trade and subsistence use of bamboo, valued at more than US$7 000 million. The plant has more than 1 500 documented uses, ranging from fuelwood to light bulbs, medicine, poison and toys to aircraft manufacturing. Over 1 000 million people live in houses made of bamboo or with bamboo as the key structural, cladding or roofing element. China earns US$130 million and Taiwan Province of China about US$50 million annually from exports of edible bamboo shoots. China 's annual exports of woven bamboo products are valued at US$117 million. India uses bamboo in its incense stick industry, estimated to be worth US$400 million. Bamboo is also an important raw material for many pulp and paper industries in China , India , Thailand and other Asian countries. Bamboo finds major uses in the rayon, handloom, fishing and sericulture industries, where it provides the basis for millions of jobs.

(A. Kumar and C.B. Sastry)

Although rattan's ecological role is much less studied than that of bamboo, it is likely that rattan species with subterranean stems, such as Calamus minutus, or those with widely radiating, horizontally growing roots, such as Calamus caesium and Calamus manan, could have a significant role in preventing soil displacement.

(A. Kumar and C.B. Sastry

Extend the bamboo floor with the same length after previewing the floor specifications. It'll take on a thorough and tidy appearance.

Irregular

Extend the bamboo floor with different length, you may clop the beyond ones, then add them to the next ones. It appears to be natural, graceful and unique.

1. Put wooden frames on the dry ground. The cement must dry enough if it will be used to support the wooden frames.

2. Lay down plywood above the wooden frame.

3. Put waterproof PVC or EPE on the plywood.

4. Nail bamboo floors on the plywood. The bamboo floors must cross the wooden frames at right angles. A space of 10mm must be kept between bamboo floor and the wall. Lastly, nail the skirting board.

A study comparing the performance of Bamboo mat corrugated board

VS other corrugated boards

Wang Zheng, Ren Yiping, Guo Wenjing

(Research Institute of Wood Industry, CAF Beijing 100091, China)

Abstract--the physical-mechanical performances of four kinds of corrugated roofing boards (bamboo, plastic, asbestos and steel) have been determined in the paper. The performance of the bamboo mat corrugated board has been compared with other three kinds of corrugated boards. The results have shown that the bamboo mat board has very good properties in the thermal and sound isolation, combustion-proof, and mechanical strengths comparing with iron, plastic and asbestos corrugated boards, and is a suitable house roofing material.

Key words: Bamboo, corrugated board, roofing material, performance comparing.

INTRODUCTION

Bamboo is one of the most important forest resources in China and with wide uses. It is very important that the bamboo is used for new architecture material. One possibility is the use of bamboo mat in corrugated board form intended for roofing material (tiles). The technology is a good example for advancing bamboo value and utilization rate. The aim of the study is to determine the physical-mechanical properties of the bamboo and other material corrugated boards, comparing performance differences among the different corrugated boards and determining the relative advantages of the bamboo corrugated board product comparing with other boards. These data are offered for enlarging the marketing of bamboo-corrugated board.

Experimental MATERIALS AND METHODS

Materials

There are four kinds of roofing materials in the study: bamboo mat corrugated boards which are produced by Shanfang Bamboo tile company, Gejiu city Yunnan province; The iron sheet corrugated board, plastic/glass-fiber composite corrugated board and the asbestos corrugated board; the later three are bought from market. All tested boards have the size of 720mm×610mm×thickness.

Testing methods

1 Heat transmission performances of the different material boards, comparing the bamboo mat board with the iron, asbestos and the plastic composite boards. The test standard used here is the national standard of GB/T13475-92, ‘Building element---Determination of steady thermal transmission properties---Calibrated and guarded hot box’. The thermal resistances and the thermal transmittances of the four materials were determined.

2 Noise transmission performances of the different material boards, comparing the bamboo mat board with the iron, asbestos and the plastic composite boards. The test standard is the national standard of GBJ75-84, ‘the air sound insulation of architecture component’. In the testing the material with the worst sound obstructing is used as the basic level, comparing with other materials sound obstructing efficiency in decibels.

3 Noise transmission through impact: a shelf with acclivitous channel trough is emplaced in a pacific sound insulation laboratory. At the end of the trough, there is a hole. When the testing beginning, small steel balls dropdown from the hole, strike the corrugated board sample below on a wood frame and make a sound. The sound that every sample sends out is determined three times for getting the average. The height of steel balls free dropping to the sample is 1 meter. The size of the wood frame is 720mm×610mm×100mm. Glass cotton with 100mm thickness is filled in the wood frame in order to prevent resonance. The noise performance of the different material boards viz. the bamboo mat, the iron, the asbestos and the plastic composite corrugated boards, are compared.

4 Combustion proof performances of the different material boards; as the asbestos and iron boards are non-burning materials, only two kinds of boards, bamboo mat board and plastic composite board were determined and compared. Testing standard: the international standard, ISO 5660-1:1993, the Combustion proof performances of materials is cited.

5 Other physical-mechanical properties determination; the following physical-mechanical indexes are appraised: density and water absorption: citing standard: the calling standard LY/T1203-1997 ‘the roofing corrugated wood fiber hardboard’; bending strength: citing the national standard, GB9341-88, ‘Plastics-Determination of flexural properties of rigid plastics’; and impact strength: citing the national standard, GB/T1043-93, ‘Plastics- Determination of charpy impact strength of rigid material’. The properties of bamboo mat board are compared with asbestos and plastic corrugated boards.

Result and Discussion

Thermal transmission performances of the different corrugated boards The testing results of the thermal transmission properties of the four kinds corrugated boards are shown in the table 1.

Table 1.Thermal transmission properties of the four kinds corrugated boards

From the results of the table 1, it has shown that the bamboo mat corrugated board has the highest thermal resistance and the lowest thermal transmission coefficient. The bamboo corrugated board has the best thermal isolation property compared with other three materials.

Noise transmission performances of the different material boards

The testing results of the noise transmission performances of the different material boards have shown in the table 2.

Table 2. The noise transmission of four kinds corrugated boards

From the results of table 2, it has shown that the plastic composite corrugated board has the worst sound insulating performance (using the sound obstructing data of the plastic board as the reference, and setting its sound insulating at 0 dB). The asbestos corrugated board has the best sound insulating performance. It’s sound obstructing performance is 15 dB higher than that of plastic composite board. The data from table 2 has also shown that the bamboo mat corrugated board has the quite good noise insulating performance. It’s sound obstructing data higher 9 dB than that of the plastic board and therefore better than the steel sheet (which is only 4 dB better than the plastic sheet). The dB scale is logarithmic which means that the sound insulation of the bamboo board is ten times greater than the plastic sheet.

The impact sounding of the different boards

The testing results of the noise caused by impact vocalism of the four kinds corrugated board have shown in the table 3.

Table 3. The impacting vocalism of four kinds corrugated boards

These results say something about the transmission of the sound of falling rain through the roof. From the results of the table 3, it has shown that the iron sheet corrugated board has the highest sound delivering level and it has been set as the reference (0 dB). Comparing with the iron board, the bamboo mat board, the plastic board and asbestos board lower the transmition of the sound by steel balls impinging by 3dB, 4dB and 4dB respectively. The results have explained that the plastic board and asbestos board have very slightly the best reducing sound performance, and the reducing sound performance of the bamboo mat board is better than that of the iron sheet board. A reduction of 4 dB is 40%.

Combustion proof performances of the different material boards

The results of the combustion-proof performances of the different material boards are shown in the table 4. As the iron and the asbestos boards are non-burning materials, only two kinds of materials, bamboo mat and plastic corrugated boards have been determined.

Table 4.The combustion-proof performances of two kinds of corrugated boards

From the table 4, it has shown that the peak heat release rate of the bamboo mat board is nearly half of the plastic board and the peak heat release time appears later than that of the plastic board when the two kinds of materials burn. At the 180 second burning time, the plastic board has no heat release, revealing its faster burning speed. For the average heat release rate and the average effective HOC (heat of combustion), the bamboo mat board is much lower than that of the plastic board. The total heat release of the bamboo mat board is higher than that of the plastic board because it is much thicker than the former (the thickness of the bamboo mat board is 3 mm and that of the plastic board is 0.5 mm). These results have shown that the bamboo mat corrugated board has better combustion-proof properties, for example slower burning speed, smaller combustion heat and lower heat release rate compared to the plastic corrugated board.

Other physical-mechanical properties of the different corrugated boards

Some other physical-mechanical property results of three kinds of corrugated boards are shown in the table 5 to table 7. The following physical-mechanical indexes: density and water absorption, bending strength, and impact strength are appraised.

1 The densities and water absorption properties of the corrugated boards

The results of the density and the water absorption of the three corrugated boards have been shown in the table 5.

Table 5.The density and water absorption of three kinds of corrugated boards

The table 5 has shown that the bamboo mat board has the lowest density and the highest water absorption ratio, showing that this kind board is not heavy weight but absorbs water or moisture easily comparing other two kinds of boards.

2.The bending strength of the corrugated boards

The results of the corrugated board flexural strength are shown in the table 6. Because n the plastic board was too thin to determine its strength properties, the determination was done with bamboo mat and asbestos boards only.

Table 6.The flexural strength of two kinds of corrugated boards

The data in the table 6 has shown that the bamboo mat board has a higher bending strength than that of the asbestos corrugated board. This means that, ceteris paribus, the bamboo mat board can endure larger long time load in employment.

3.The impact strength of the corrugated boards

The results of the impact strength of the two kinds of corrugated boards have been shown in the table 7.

Table 7.The impact strengths of the two kinds of corrugated boards

The results of table 7 show that the bamboo mat corrugated board has excellent impact strength and the bears a much higher instant striking force comparing with the asbestos board.

Conclusions

Comparing with other three corrugated board materials, the bamboo mat corrugated board has the following advantages: the best thermal isolation property, the lowest density, quite good noise insulating performance and lower noise transmission after impact. Comparing with the plastic corrugated board, the bamboo mat corrugated board has batter combustion-proof properties, which means slower burning speed, smaller combustion heat and lower heat release rate. The bamboo mat board is better in the bending strength than that of the asbestos corrugated board and would be greatly superior to the plastic board (which was too thin to test realistically). This character can make it enduring larger long-time load in employment. Comparing with the asbestos board, the excellent impact strength of the bamboo mat corrugated board means that it can bear stronger instant striking force.

The disadvantage of the bamboo mat corrugated board is that it has the worst moisture-absorption performance comparing with the other three kinds corrugated boards. This may influence its durability in external utilization. However this characteristic could be overcome by using a coating upper layer to the matboard.

Acknowledgement

This research work was carried out with the collaboration and assistance of the International Network for Bamboo and Rattan. Dr. Tan Hua and Dr. Qian Meili of the Chinese Academy of Architecture have determined the thermal and sound performances of the four kinds of corrugated boards. Dr. Wu Yuzhang of Chinese Academy of Forestry has determined the combustion properties of the corrugated boards.

References

1.P.M. Ganapathy, Zhu Huan-Ming, etc.; ‘Bamboo Panel Boards, a state of the Art Review’ INBAR technical report No. 12

2.GB/T13475-92, National standard ‘Building element---Determination of steady thermal transmission properties---Calibrated and guarded hot box’

3.GBJ75-84, National standard ‘the air sound insulation of architecture component’

4.ISO 5660-1:1993, International standard, the Combustion proof performances of materials is cited

5.LY/T1203-1997, Calling standard ‘the roofing corrugated wood fiber hardboard’

6.GB9341-88, National standard, ‘Plastics-Determination of flexural properties of rigid plastics’

7.GB/T1043-93, National standard, ‘Plastics- Determination of charpy impact strength of rigid material’