建筑材料的水分热量分析(英文版)

Chapter 1 Bamboo as a Building Material 1.1Bamboo and bamboo construction 1.1.1Bamboo resources Bamboo grows widely in tropical and subtropical zones in the Asia-Pacific，Americas，and Africa.The Asia-Pacific bamboo area has the most abundant bamboo resources，where the bamboo forest accounts for 67% of the total amount.In this area， bamboo has been utilized in daily life for a long history and still plays an important role in modern times.Bamboo is always regarded as the“wood for poor people”，since most of the bamboos are in natural growth and lack of high value-added utilization.However，several countries alone in the Asia-Pacific bamboo area are able to manage their bamboo forests intensively(Table 1.1). Among these countries，China has the most abundant bamboo resources in the world，with the bamboo forest and raw bamboo output accounting for about 1/4 and 1/3 of the global total， respectively.More than 85% of the bamboo based panels are produced in China with the leading bamboo processing technology.However， under the strict policy of protecting natural wood forests， about 50% of the timber has been imported in the past years.As“substitute timber with bamboo”represents key national strategic initiative，it is of great significance to study how to properly use bamboo in building industry(Figure 1.1). Industrial bamboos，in standard form of panel or square，are regarded as idea l substitutes for timber.Since 1980s，the timber processing technologies have been introduced to the modification of bamboo，and series bamboo products parallel to their timber peers have been successfully developed. The representative bamboo panel variants include the plybamboo(including bamboo mat board， bamboo curtain board，etc.)developed in the 1980s，the bamboo particleboard，laminated bamboo and bamboo-oriented strand board developed in the 1990s，the bamboo scrimber developed in the 2000s，as well as the flattened bamboo board and bamboo winding developed in the 2010s.The bamboo industry in China has moved towards a way of industrialized and high value-added utilization(Figure 1.2). Among the bamboo based panels，laminated bamboo and bamboo scrimber are widely used as decorative panels because of the good surface appearance.In 2012，China produced approximately bamboo flooring panels，of which around were made of laminated bamboo，and the rest were bamboo scimber and some other bamboo composites.Plybamboo is another successful product that has been widely used in packaging，concrete formwork sectors，and also structural members in building industry.As the earliest developed bamboo based panel，its production technologies have been very proven，making it own advantages of low cost and low technical requirement.By comparison，the bamboo particleboard and bamboo OSB are unable to achieve large-scale marketing.These two are developed，respectively，as products parallel to the wood medium-density fiberboard(MDF) and wood OSB，the two mainstream products in timber industry.However，unlike wood MDF and OSB，the bamboo particleboard and bamboo OSB are limitedly used in packaging，furniture and concrete formwork sectors. 1.1.2Environmental benefits of bamboo as local building material The local application of bamboo products has potential to improve the building sustainability.Compared with the wood，concrete，and steel in environmental and financial aspects，bamboo is considered to be a competitive building material under certain boundary conditions.A carbon emission calculation of the“Glubam”，a kind plybamboo parallel to the“Glulam”in timber industry，shows that the total carbon emission during the production is-261.00kg/m3，smaller than the-168.00kg/m3 of Glulam.However，long distance transportation will weaken the environmental advantage of bamboo.For example，an environmental impact calculation for the carbonized 1-layer plain pressed laminated bamboo board in the“cradle to gate”stage shows the transportation from the factory in China to the warehouse in the Netherlands accounts for 34.0% of the total eco-costs，and for the raw bamboo stem，the proportion of transportation section even reaches as high as 98.3%. In South China，there are some dominant bamboo species，such as the Phyllostachys pubescens，Dendrocalamus sinicus，etc.Meanwhile，this area is also an economically developed region of the country，where the building industry has stronger demand for ecological materials such as wood-based products.Compared with the wood-based material products，bamboo has higher heat transport and storage capacities， as well as lower moisture transport and storage properties.A previous study by the author shows that in the hot and temperate climate regions，the room units enclosed with bamboo exterior walls show better performance than timber units with the same construction sizes，in terms of both energy consumption and indoor thermal environment.To some extent，it is conducive to the local application of bamboo in these areas where such c