Wednesday, June 5, 2019

Physical And Chemical Properties Of Bamboo Environmental Sciences Essay

Physical And Chemical Properties Of Bamboo Environmental Sciences EssayChapter 1 has been drafted in a adult malener that it is to draw the context of this dissertation. It defines the locality, and has an insight into the conjugation vitamin E Indian Bamboo industry. It attempts to justify the riding habit of bamboo as a primary whirl actual in the argona, receivable to its abundant availability. It tries to highlight the faults in the true and handed-down regularitys prevalent in the theatrical role which ar a hindrance to bamboo cosmos more(prenominal) often used for whirl. The dissertation re search looks into gathering straight proofs to support the hypothesis which comes after appreciation the problems of the ara.1.1 Bamboo dissemination1.1.1 World Wide DistributionBamboo is a plant belonging to the true grass family Poaceae, subfamily Bambusoideae, tribe Bambuseae. In bamboo, the internodal pieces of the stem ar hollow and the vascular bundles in the cros s section be scattered by means ofout the stem instead of in a rounded ar ratement. Bamboo is a native to five continents some the world Asia, Africa, South America, North America and Australia. It is found at all elevations from the coast of the Philippines up to 15,000 feet above sea level in the eastern Andes.Bamboo grows in the tropical, subtropical and temperate regions of all continents except Europe, geographically divided into 3 z angiotensin converting enzymes the Asia- Pacific zone(around 700 species), the America zone (around four hundred species) and the African zone (around 50 species). There argon to leggyy 70 genera and 1200 species of bamboo all over the world that nurse been recorded, with some more in rudimentary regions to be discovered and identified. Over 2.5 billion people worldwide use or trade in bamboo worth 4.5 billion US Dollar all(prenominal) year (INBAR 1999).1.1.2 South East AsiaBamboo is found in abundance in South East Asia, the tropical sce nario, temperature and footing conditions in the area widely promotes the evolution of bamboo in the area. China is known as the Kingdom of Bamboo, with around 500 bamboo species native here, inbornly distributed in 16 provinces and 1 municipal city, among which Yunnan takes up 220 species due to its diversified climate and geographical characteristics. Due to its abundance in availability, from the starting of time bamboo as such has been a break of all South East Asian traditions. Bamboo is an inseparable part of south east Asian culture, medicine , music, twisting and food.In twisting, bamboo provides pillars, floors, walls, doors, window frames, rafters, room separators, ceilings and roofs. The meeting houses of some New guinea fowl villages are 20 m tall and more than 40 m long, with huge bamboo poles set deep into the ground and bent over in the work on of Gothic arches to carry the thickly thatched roof, creating some of the boldest structures reinforced with minimal e quipment and engineering science. Japanese houses are far more sophisticated, but are still typically built of wood, paper and bamboo. Bamboo is used to make guard houses in rice fields, roadside food shops, hot houses for growing mushrooms, smoke houses for drying tobacco or rubber, store houses for rice and separate produce, and livestock sheds. Bamboo is alike used to make pegs which replace nails. Bamboo scaffolding finds extensive use in Asian cities, even on truly tall buildings. Bamboo is used by means ofout rural Asia to build bridges of many types and sizes they can be as long as 25 m, often involving sophisticated technology as suspension bridges, but also with simple technology in the form of pontoon bridges (Kurz 1876). Many villagers use bamboo shingles, with the large stems split in fractional and laid with the convex and concave sides alternately facing upwards, with their edges overlapping. In coastal areas, roofs often are make of thatch woven from nipa palm a round long slivrers of bamboo.Location Bamboo field of operations(10,000 hectare) Bamboo SpeciesChina 500.00 500India 400.00 136Burma 217.00 90Thailand 81.00 60Bangladesh 60.00 30Cambodia 28.70 Vietnam 13.00 92Japan 13.80 230Indonesia 6.00 30Malaysia 2.00 44Philippines 2.00 55Korea 0.80 13Sri Lanka 0.20 14In countries like China, Japan and Korea, bamboo also is a frequently used popular motive for poets and painters. Philosophers and literateurs took bamboo as a symbol for a good character making progress modest straight (Wang 2000) there, bamboo is non only a useful satisfying for their everyday life, but also has al piss been developed into a so called bamboo culture through the long time of cohabitation with people.1.1.3 India Why North East India?India is home to about 45% of the worlds bamboo output. There are 125 species of bamboo in India spread across 18 genera. According to a survey by BMTPC (Building Materials and Technology Promotion Council) India produces about 1 3.5 Million Metric dozens of bamboo annually from 9.6 Million Hectares land area (used only for bamboo plantation). Sympodial bamboo consists of 67% of growing stock and monopodial bamboo comprises of 20% of growing stock. Out of this amount the North Eastern part of India alone has the gross share of 66% of the total production. So, it can be said that potentially this region has the widest range climate and topography adapted for growth of bamboo.Distribution of Bamboo in North East India(Area in sq km * )S. No. State Area under Bamboos Area under Muli Bamboo Area under other Bamboo Spp. Area expected to flower Area accessible (Flowered)1. Arunachal Pradesh 4590 100.002. Assam 8213 2950 14563. Manipur 3692 1592 4004. Meghalaya 3100 400 2700 400 2005. Mizoram 6646 5100 1500 5100 12006. Nagaland 0758 250 2507. Tripura 2397 960 1437 2397 300Bamboo is a vital element of Indias North Eastern region comprising the states of Assam, Arunachal Pradesh, Manipur, Meghalaya, Mizoram, Nagala nd, Sikkim and Tripura. Bamboo has been a traditional material of gimmick that has been used in the north east region from quiet some time. In Borneo and the Naga Hills of India, large communal houses that whitethorn be 100 m long are built of bamboo. In Arunachal Pradesh, large suspension bridges have been made out of bamboo, In Assam houses made of bamboo are the typical house type in villages which stand the test of floods and earthquakes in the region. Bamboo is the material of survival of the fittest when it comes to arts and craft in the region. A form of traditional musical instruments are also made from bamboo.The virtues of bamboo are not new, but the interest in it is, says Antonios Levissianos, UNIDO senior industrial development officer. Bamboo is no long-dated seen as a poor mans timber, it is growing to be the most promising substitute for wood and there is great scope for shape up generating rural employment. Indias flow demand for bamboo is an estimated 27 mill ion tones. However, only 50 per cent of that demand can be met because of lack of facilities for value step-up and transportation.1.2 Why Bamboo?Bamboo is one of the foremost sustainable innate(p)ly available material that has been used in facial expression since ages. Bamboo is the traditional material of choice that has been in use in the North East region of India since time immemorial. Bamboo is enduring, versatile and renewable, and due to its vast production (13.5 million metric tonnes annually), it was also the material of choice in construction. Bamboo can replace a variety of woods that are being increasingly used for construction immediately, and thus help in saving forests which today are in a critical stage of deforestation. Also, bamboo converts more carbon-di-oxide, than most other plants, and hence a more eco-friendly material. The growth rate of bamboo is also trio times to eucalyptus and it can be harvested four times in the same period, hence its production an d availability is much more compared to wood. So, bamboo should be the material of choice in the field of construction and not only as a scaffolding option as it is mostly used today, at least(prenominal) in the regions where it is readily available and in bounty.1.2.1 Physical and chemical Properties of bambooPhysical PropertiesPhysical primties of bamboo varies greatly from species to species, and to some extent within a species. Culms are primarily long and straight and the hollow internodes make it comparatively light. The strength of bamboo varies within the species, age of culm, moisture content and portion of culm and generally increases until it reaches maturity. The tensile strength of a bamboo pole is high parallel to the grain. Bamboo however, fails in shear before it fails in tension and so modulus of rive is used to calculate strength. Due to its weak transverse bonds between its fibres, it can be spilt easily along the length (radial or tangential)Chemical Propert iesThe main constituents of the bamboo culm are cellulose, hemicellulose and lignin. Other constituents consist of resins, tannins, waxes and inorganic salts. The composition varies found on years of growth, pacify, species and the part of the culm. Studies on moisture, ligno-cellulosic, starch and silica content are presented in this section. The main percentage composition of a bamboo pole are mainly Cellulose Fibers 40% Parenchyma 50% Vessels (voids) 10%Mechanical PropertiesThe fibers contribute 60-70% of the weight of the total culm tissue. They are long and tapered at their ends. The ratio of length to width varies between 1501 and 2501. Fiber length has showed considerable variation within species. There is also variation in strength properties along the culm acme as well. Compressive strength passs to increase with height Espiloy 1987 Liese 1987 Sattar et al. 1990 Kabir et al. 1991. The strength increases from the central to the outmost part. There is more than 100 p ercent variation in strength from the inner(a) to the outer layers Narayanamurti and Bist 1947.1.2.2 Bamboo In comparison to other prevalent construction materialsA comparative study of the energy unavoidable to produce a unit of a building material with a certain level of load-bearing capacity gives an idea of the sustainability of bamboo.Due to its hollowness and the fibres being in the longitudinal direction, bamboo is a very economic material for structural design, as less material is needed than in case of traditional construction materials such as steel and cover as massive sections can be avoided. In case of load bearing mass, due to its tubular structure bamboo behaves as a I-shaped cross-section, in each of the direction of its load, but it is less efficient than other cross sections in one or two directions.The mechanical properties, the high extent of flexibility, its exceptionally stiff growth rate, comparatively lower weight and low cost make bamboo a preferable bu ilding material over other construction materials. Although, in its natural state bamboo is little efficient to be used as a construction material due to its proneness to decay and insect attack, so, bamboo ask to be treated before it can be used as an extensive construction material.1.2.3 Bamboo as a sustainable construction materialBamboo is not a tree, it is a grass, so unlike trees it does not yield timber. Bamboos environmental benefits arise largely out of its ability to grow and spread rapidly in some cases three to four feet per day without the need for fertilizers, pesticides or much water.A bamboo grove also releases some 35 percent more oxygen into the air than a similar-sized stand of trees, because of this, planting bamboo is a great way to reduce your carbon footprint and help fight global warming, a perfect picking for going green and it matures (and can be replanted) within seven years (compared to 30-50 years for a stand of trees), helping to improve soil condi tions and prevent erosion along the way. Bamboo is so degenerate-growing that it can yield 20 times more timber than trees on the same area.As a building material, bamboo is also ideal in that it is sturdy, and can be cut and laminated into sheets and planks, just like wood. The quality of bamboo laminate varies between manufacturers and the maturity of the plant from which it was harvested the sturdiest products fulfill their claims of being up to three times harder than oak hardwood but others may be softer than standard hardwood. Again, the many varieties of bamboo give it the advantage of versatility. For countries who are poor and struggling to can away from polluting industries, growing bamboo has the potential to become a viable economic and environmental solvent. Bamboo if used as a major(ip) construction material, addresses three major areasECOLOGICAL SECURITY conservation of forests through timber substitution, alternate materials to non-biodegradable high energy consu ming materials like metals and plasticsSUSTAINABLE FOOD SECURITY bamboo establish agro -forestry system, care of soil fertility of adjoining agricultural lands, and bamboo shoots.LIVELIHOOD SECURITY generation of employment in planting and primary processing for manufacturing mat based composites and other market driven bamboo products.Bamboo poles can be used to make papers and clothes, and the process is environment friendly as little harmful chemicals are required to make paper and clothes out of the bamboo plant. The environmental impact of bamboo is what makes it an ideal material for construction in both interior and exterior of any building.1.3 Bamboo usable in Construction1.3.1 Durability of bamboo structureBamboo is a natural composite with remarkable growth rate, and potent physical and mechanical properties which makes it one of the most suitable replacement for wood and a major and most sought after sustainable building material in the region of its growth. But bamboo in its natural state is not a very durable material and is very prone to infestation and decay. Thus, most bamboos used for structural purposes in rural and tribal housing deteriorate in a couple of years, putting heavy pressure on the resource, owing to increased demands for frequent replacements. This adversely affects the supplies of bamboo, even in bamboo rich regions.India, with an annual production of about 3.2 million tones of bamboos, ranks second only to China in bamboo production (Pathak, 1989). Over 136 species in 30 genera occur in India (Suri and Chauhan, 1984). The two most widely distributed genera in India are Bambusa and Dendrocalamus. In South and Southeast Asia, the most economically important species for structural uses from the point of run across of easy availability are Bambusa balcoa, Bambusa bambos, Bambusa blumeana, Bambusa nutans, Bambusa polymorpha, Bambusa tulda, Barnbusa vulgaris, Dendrocalarmus hamiltonii, Dendrocalarnus strictus, Melocanna barnbusoid es, Gigan tochloa spp., Ochlandra travanicorica and Oxytenathera nigroeiliata.Unfortunately, like most lignocellulosic materials, bamboo has very low resistance to biologic degrading agents. Several techniques to enhance its durability have, therefore, been developed.Natural Durability of BambooWorldwide and mainly in the South East Asian mainland where bamboo grows in abundance there are a great many traditional and chemical methods for the preservation and enhanced durability of bamboo. However, here we mainly discuss briefly the traditional method of increasing the durability of bamboo which are tested and practiced in the north east Indian region which is the main producer of bamboo in the country. Variation in durability has also been observed along the length of the culm and the thickness of the wall. The lower portion of the culm is considered more durable, while the inner part of the wall deteriorates faster than the outer harder portion. This is probably link to the anato mical and chemical nature of the woody cells.Because of the lack of any toxic constituents, bamboos form a ready food source for a variety of organisms. The presence of considerable quantities of starch in green or dry bamboo makes it more attractive to such organisms, especially stain fungi and rock drill beetles. Some sap sucking insects have been reported to attack bamboo plantations as well (Chatterjee and Sebastian, 1964,1966 Singh, 1988). The most serious borers of felled bamboos are three species of Dinoderus (celluris, minutes, brevis) and Lyctus, which attack bamboo rich with starch (Casin and Mosteiro, 1970 Sandhu, 1975). They cause immense damage during drying, storage, and subsequent use. Carpenter bees and termites also attack bamboo (Beeson, 1938Sensarma and Mathur, 1957). Bamboos are attacked by marine organisms as well (Anon, 1945).It is reported that bamboos harvested during summer are more rapidly destroyed than those felled in the rainy season (Liese, 1980). Culm s of bamboo plants which have flowered are more resistant to beetles because of starch depletion. Hence, the first point of term for the durability of bamboo is harvesting.Harvesting of BambooIn bamboos, soluble lucres are the principal nutrients for parasites. Thus, bamboos with depleted carbohydrates become reasonably resistant to the attack of borers and staining fungi. Methods adopted for lowering the sugar content at the time of harvesting of bamboos are(i) Life CycleFelling of bamboo at maturity when sugar content is low- Sugar content in bamboos varies with age. It is lowest during the first year but felling of one-year-old bamboo is not desirable because of very low strength and yield. Normally, bamboo matures at 3-4 years(ii) Annual CycleFelling of bamboo during low-sugar content season-Sugar content in almost all plants varies with seasons. In India, for example, it is higher in spring than in winter (Joseph, 1958). Therefore, it is advisable to harvest bamboos between A ugust and December, which is essentially the dry season before monsoons.(iii) Daily CycleFelling of bamboo after sunset- During the day time due to the availability of sunlight a lot of photosynthesis occurs in the bamboo plant and hence a lot of lawsuit of food occurs resulting in increased starch content in most parts of the bamboo tree. But during the shadow mainly stored food is used and no photosynthesis happens, so it is advisable to fell the bamboo tress after sunset.Leaching of BambooThe bamboo available after harvest is not ready yet, it still has a large amount of sap content which makes it prone to infestation and decay. Leaching is the remotion of sap after harvest. The sap levels in harvested bamboo are reduced either through filtering or postharvest photosynthesis. A variety of leaching practices are used to remove the sap content, the mostly used embarrass1. Cut bamboo is raised clear of the ground and leant against the rest of the clump for one to two weeks unti l leaves turn yellow to allow full consumption of sugars by the plant.2. A similar method is undertaken, but with the base of the culm standing in fresh water, either in a large drum or stream to leach out sap.3. Cut culms are immersed in a running stream and weighted down for three to four weeks.4. Water is pumped through the pertly cut culms, forcing out the sap (this method is often used in conjunction with the injection of some form of treatment).In the process of water leaching, the bamboo is dry out slowly and evenly in the shade to avoid cracking in the outer skin of the bamboo, thereby reducing opportunities for pest infestation.Storage of BambooThe bamboo after removal of the sap content is than ready to be stored in storages but certain precautions are taken to enhance the durability of bamboo, they are1. Bamboo is not stored in the reach to avoid exposure to climatic forces such as rain and direct sunlight.2. Bamboo is stored in a semi closed area to allow wind movemen t through its stacks.3. Bamboo is stored a bit (app. 10cm) above the ground to avoid infestation from below, also an insect repellent may be sprayed on the ground.4. Bamboo is stacked in vertical manner, and it should be noted that a minimum of 30% of the moisture in bamboo should be retained.These measures taken ensures that the bamboo is stored properly and is well protected from reagents, and ready for selection and grading.Selection/ Grading of bambooThe bamboo culms are now ready for selection and grading into various categories, which are then accordingly put to use in the construction as per the nature of demand of the work. The main characteristics of a good, durable and structurally usable bamboo culm are based on the hobby key points along with a idea of advisable range of values.1. Age and Maturity plus 5 years2. Dimensional Characteristics 4 63. Wall Thickness 12mm 25 mm4. Inter Nodal Distance5. Straightness and Uniformity1.3.2 Treatment processes of bambooAltho ugh a great deal of care is taken in increasing the durability of bamboo right from the commencement ceremony from the process of harvesting to the selection and grading, the natural bamboo still is not good for long standing structures due to its still proneness to infestation. Hence, the bamboo is made to go through a number of treatment and preventive processes.Natural means-1. water seasoning 3-4 months2. smoke seasoning3. heat seasoningChemical means-1. internodal injection treatment- petro based chemical, creosote oil+diesel (11) 25-40ml2. borax boric solution- 11 in hot 25L of water 50g of each3. vacuum pressure treatment4. brochh-vsie treatment gravity based1.4 Current State of Problems1.4.1 A Glance at the drawbacks of traditional bamboo construction in North East IndiaSince time immemorial bamboo has been an integral part of the traditional practices of the people of north east India. The north eastern parts of India, bamboo is in abundance due to its topography and ge ographical conditions, and bamboo has found its use in many variations and utilities, ranging from bamboo as a construction material, a key element of interiors such as furnitures and home decor, to daily household usable commodities. Bamboo shoot is a delicacy overnice to the North Eastern region of India.Although available in bounty in nature, the state of bamboo usable for construction purposes is in a state of bother in the region. The traditional methods of bamboo usage and construction can be said to be inadequate to meet long term goals of sustainable and long lasting and persistent structures. The virtues of bamboo are not new, but the interest in it is, says Antonios Levissianos, UNIDO senior industrial development officer. Bamboo is no longer seen as a poor mans timber, it is growing to be the most promising substitute for wood and there is great scope for further generating rural employment. Indias current demand for bamboo is an estimated 27 million tones. However, onl y 50 per cent of that demand can be met because of lack of facilities for value addition and transportation. According to Antonios if proper infrastructure is provided for transportation, either by way of roads or canals, bamboo can be a material with great potential to be used in the construction industry in the NE region of India.If we are to highlight a few key points as to what leads to the failure of the current traditional system of bamboo usage in the construction industry we can consider the following key points(i) Bamboo not TreatedIn the current practice system of bamboo usage in the region the bamboo after the process of harvesting as discussed in section A3 3.1, it undergoes little treatment procedures, which makes it prone to infestation and attack from natural reagents.(ii) Lack of Proper JoineryThe current practice involves crude joinery mechanisms to join two bamboo structural members, which are derogatory and have inverse effects on the life of bamboo and also tend to cause in rupture of the bamboo members.(iii) Lack of Safety measures from Climatic ForcesThis is one of the major cause of failure of current bamboo structures, as the natural climatic forces have an adverse effect on the untreated bamboo. The lack of solid and stable joinery is exploited by the wind in the region whereas, the rain and floods exemplify an even dangerous effect to the untreated bamboo.1.4.2 Identifying the Possible problems in constructing with bambooThe state of bamboo in the North Eastern region of India can be easily be improved if we identify and improve upon the key points or the distinct nodes of the problems, that are associated with the traditional method of construction of bamboo. After a look into our study so far, if we are to list some key issues which needs to be addressed upon as the main nodes to look at for making bamboo a suitable and efficient material of construction we can list out the following points.1. Appropriate technology for bamboo tre atment and working toolsThe region does not have a proper treatment facility for the treatment of harvested bamboo which will protect it from insect and reagent attacks as well as slow its decay process due to effect from natural forces. Moreover, no specialized tools are available for working with bamboo and most of the work is done with tools developed for wood/timber as such it results in rupture and wear and tear of bamboo elements which can be avoided by proper use of tools developed especially for bamboo.2. Design of proper joinery system- conducive effective production to bamboo materialThe current joinery type used for bamboo based construction is either by tying by ropes or bolting with iron bolts as shown in Fig. 11, the rope tied bamboo joints tend to fail the test of time and climatic forces, whereas the bolting results in unwanted cracks and rupture of the structural bamboo elements.3. Skilled labour- workmanshipAlthough bamboo has been the choice of material since long in the region , a relatively low quantity of labours can come up to the level of being called a primary bamboo construction workman. This is a major setback as to when an architect or builder decides on constructing with bamboo as there is serious lack of skilled labour for bamboo construction. So, the region demands a specialized center for training persons in bamboo construction who can in turn come up to be the skilled bamboo works man for the region. This can inturn help to generate employment for the local public, who after being trained can work as bamboo craftsman in the industry.E.g. Hong Kong Bamboo Scaffolding grind4. Change in Social mindsetA major setback related to bamboo construction in the region is the social mindset of the people who are of the idea that bamboo is a poor mans timer, and fail to understand the potential and beauty of the bamboo material. A through policy for propagate to mass with appropriate technology has to be introduced in a systematic manner w hich is competitive, durable, aesthetically pleasing and eco friendly.CHAPTER 2 HYPOTHESIS2.1 STATEMENTBamboo is a natural material, it is non-uniform, and degradable in its natural state. However it is one of the most sustainable building materials used till date. However, the key area of concern and the biggest obstacle in the bamboo being used more often in construction is, due to its dimensional constraints the joinery system for the structural elements of a bamboo construction becomes extremely difficult and non-durable. However, custom made joints, which are flexible and also adjustable can help solve the problem as it can convert a non-standardize construction material to a standardize material. Moreover, factory setups for availing the construction industry with well treated, and standardize bamboo elements as well as products can help a great deal in making bamboo the material of choice for construction in the region.Customization of the joinery system of bamboo elements al ong with better industrial setup for bamboo and bamboo based products will make bamboo a primary construction material.2.2 methodological analysisLiterature comprising books, research notes, websites, published papers, news articles and e-mail correspondence were means of research undertaken. the author also visited Assam from 13/05/2012 to 10/06/2012 for observations and discussions with professionals. There were site visits conducted during the period.The understanding developed was in the form of why the traditional method of bamboo construction is inadequate and what are the major problems which limit bamboo usage as the primary construction material. These were then explained in terms of case studies with examples from India and rest of the world. The case studies and the problems are then evaluated to reach a conclusion which hint at possible solution to make bamboo a standard and primary construction materialChapter 3 CASE STUDIESBamboo itself has a lot of advantages using it for building houses, bridges . It is a cheap, fast growing material with excellent statistics according to the mechanical properties. However, although it is abundantly available in North East India there are some major problems related to bamboo based construction in the region which has been discussed in clause 1.4.2 of chapter 1 of this report. There may be a lot of solutions possible for the above mentioned problems, which are a hurdle to the establishment of the hypothesis statement. In order to throw some light on as to how these problems can be looked at and approached, the following case studies are picked from India and abroad.3.1 Case Studies Addressing to Standardization of Bamboo MaterialStandardization of the bamboo material is a very important aspect towards establishing bamboo as a primary construction material. Bamboo is a natural material, and is non uniform and degradable in nature. Moreover, in the current industry setup there are no specific tools to be worked on bamboo, this as a result makes bamboo a vulnerable material of construction in the region. But, if the bamboo material is somehow standardize, be it whole bamboo or split bamboo, and specific tools are applied for its processing than it is possible to use bamboo and bamboo based products in a way we now use brick and concrete.3.1.1 BMTPC InitiativeThe BMTPC (Building Materials and Technology Promotion Council) of the Ministry of Housing urban Poverty Alleviation Government of India is looking forward to promote the increased use of Bamboo throughout the country. According to the BMTPC, the strength of bamboo culms, their straightness and lightness combined with hardeners and range and size of hollowers, with good physical and mechanical properties, low shrinkage and average density, it is well suited to replace wood in several applications. The BMTPC propagates the preservation of bamboo through the IS90962006, Code of Practice for preservation of bamboo for structural purpose. It covers the type of preservation, the treatment procedure for structural purposes like posts, scaffolding, walls, trusses etc.For the process of standarization the BMTPC has

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