Most of straw is derived from crops like rice, barley and wheat while much smaller amount are derived from oaths, maize, oilseed, rape and field beans (Jenkins et al., 1998). Cob is labour intensive, but it is extremely satisfying. They were air dried for 28 days and frequent weight and size measurements were taken. Cob is an ancient technique of building, which is a combination of sand and clay, mixed with straw and water. A review of BREEAM, LEED and the WELL Building Standard. Cob houses are made of clay-like lumps of soil, sand, and straw. COB: Chairman of the Board: COB: Comitê Olímpico Brasileiro (Brazilian Olympic Committee) COB: Commission des Operations de Bourse (French stock market regulator) COB: Central Obrera Boliviana (Bolivian labor organization) COB: Council of Bureaux (International Association of National Motor Insurers' Bureaux) COB: Community of Believers (various organizations) COB Adoption comes during organisation's annual general meeting. The tests were carried out in conformation with the procedures on ASTM and British Standard specification. Cob, also known as cobb, is a building material that comprises subsoil, straw (or another fibrous organic material), water, and occasionally lime. Cob construction can save money, resources and time … ; What does COB mean? The binder fraction of the material used during the tests consisted substantially of clay minerals therefore binder fraction will be used to refer to these clay minerals. COB. This is partly due to no allowances for densities COB Stands For: All acronyms (308) Airports & Locations (1) Business & Finance (18) Common (2) Government & Military … Cob is an ancient technique of building, which is a combination of sand and clay, mixed with straw and water. 'College Of Business' is one option -- get in to view more @ The Web's largest and most authoritative acronyms and abbreviations resource. 1. between the coarse particles and the strength will then depend more on the moisture I initially (and still are) an excited follower of Rammed Earth for many of the same reasons you are interested in your cob construction and ran into the same issues here in the Midwest. The study determined some of the engineering properties of cob for its suitability as building material. It can add-on, cut-out, or reshape anytime, even after the cob is dry. In the UK we ensure our cob houses last for hundreds of years by incorporating a few basic design features that make them suitable for our climate. Unlike straw bale and adobe construction, cob building does not use dried bricks or blocks.Instead, wall surfaces are built up with lumps of damp cob mixture, compressed, and sculpted into smooth, sinuous forms. Yes your cob style construction has issues or should we say the location and climate thereof does but this is the mother of invention or ingenuity. The full length of it means “close of business” and it represents the time when you are supposed to go home from work. COB - Clear over Base COB - Close of Business. business, finance, engineering. The general trend is an increase in strength due to a reduction in moisture One of the advantages of using cob is that the walls can be built up to any shape required, making it very flexible in terms of design. Think of cob building as house sculpting. Different kinds of materials have been used in building from age to age depending on the locality and the technological advancement therein. The oldest cob house still standing is 10,000 years old. cob construction definition in English dictionary, cob construction meaning, synonyms, see also 'constructional',constructionist',construct',constructionally'. 2. easy guideline for suitability is the plasticity index (PI). COBie - Construction Operations Building Information Exchange. Clay soils require the addition of more sand than do silty soils, but the overall quantities of sand and straw needed for a modest cob building are surprisingly small. COC - Certificate of Conformance/Conformity CoC - Chain of Custody. content range from liquid limit (LL) to the plastic limit (PL). m-2 irrespective of straw content. In this way, the walls are built up steadily, tapering slightly as they rise. Cob is a very old method of building with earth and straw or other fibers. For materials finer than 0.425 mm, which includes all the silt and clay, an A suitable roof overhang is necessary to protect the cob walls and foundation from moisture. Here are 9 tips for getting building approval for your cob house construction. The foundation must be wider than the wall, typically by around 300 mm, and sufficiently deep for the load requirements. Because the mud mixture is porous, cob can withstand long periods of rain without weakening. The rice straw is usually the golden brown color and it is the part of the plant actually carrying the rice grain. 4. Rice straw: Straw gives Cob its tensile strength-the ability to move and bend without breaking and to withstand ground movement and shear forces (Michael, 2000). Cob is a popular choice for areas that prone to wild fires or other extreme weather. Generally when the proportion of the Cob is highly resistant to weathering, because of its porous nature; it can withstand long periods of rain without weakening (Keefe et al., 2001). strength (Agarwal, 1981; Saxton, 1995). Also straw content of about 1-1.5% gave the highest compressive strength at optimum moisture content of 2-4%. The rice straw used was obtained from a hilltop in a farm in Aare-Ekiti, Ekiti State in Nigeria where the threshing of the rice from the straw has taken place. The plastic index and the plastic limit results for the soil are 23.8 and 40.5%, respectively. Ease on mixing: From the mixing processes carried out, the soil was clayey but required less time for mixing and it was easier for straw to adhere to it, this is due to the plasticity index and the liquid limit results which are 23.8 and 40.5%, respectively, while the plastic limit is 16.7%. Below a moisture content of about They are spending time, crafting their building, taking great pride in their work. cob wall "A wall formed of unburnt clay mixed with chopped straw, gravel, and occasionally with layers of long straw, in which the straw acts as a bond"- Dictionary of Architecture and Construction, Cyril M. Harris, ed., McGraw- Hill, 1975, p. 111. It is a well known fact that, when the moisture content of clayey soils increase, they become weaker. The drying rates do not appear to be influenced by straw or moisture content and are relatively uniform until linear shrinkage ceases. https://scialert.net/abstract/?doi=jas.2006.1882.1885, Indentation due to concentrated force on cob. The study determined some of the engineering properties of cob for its suitability as building material. The mixes that contained the most straw and required the most water to provide a suitable mix tended to shrink the most. The word cob comes from an old English root meaning a lump or rounded mass. There is evidence of cob being used for building construction purposes in prehistoric times in various parts of the world and it was used for centuries in the south-west of England. This strength is probably sufficient cob definition: 1. the hard cylinder-shaped part of the maize plant on which the yellow or white grain grows: 2. a…. BSRIA report compares green building ratings. Economically, Cob is one of the cheapest building materials imaginable. Moving onto the next chapter of Building Back Better. Engineering COB abbreviation meaning defined here. | Meaning, pronunciation, translations and examples Collapse is likely to be less dramatic if straw is adequately incorporated provided the straw still has required strength. The word cob comes from an Old English root meaning "a lump or rounded mass". to provide a margin of safety for structural loads with dwellings up to three Earth construction takes many forms, including adobe, cob, rammed earth, straw-clay and wattle-and-daub. Usually referring to a 5:00PM deadline. It is one of the oldest building materials on the planet (Steve, 1997). content and an increase in straw content. What is cob? In climates that benefit by some insulation, cob’s sister, strawbale construction, can be an excellent choice. Cob is Mixed into a dough like consistency, and then placed onto the walls up to two foot thick and worked in to create a monolithic wall structure. engineering, building. Due to the locality in which the study was conducted and the comparatively availability of rice in most areas, it was most reasonable to use rice straw for this testing programme. CoCP - Code of construction practice If vertical cracks develop, cob or clay tiles can be used to fix them before moisture penetration risks damaging the wall. Cob wall construction An impervious base wall below the cob for moisture protection of the cob . No forms are used, allowing the builder to create any shape desired. and the inclusion of weak specimens made too dry and lacking adequate bond. As the specimens were of similar initial dimensions, the actual water losses have been provided to provide a comparison. A look behind the Government's green industrial revolution. The present study looks into some properties of Cob as a building material. Cob Houses Are Healthy. The Cob Cottage Company is now offering hands-on cob construction workshops in most parts of North America. This amount may vary for different soil types and could be a topic for future work. WHAT IS THE MEANING OF COB AND EOD? 2. Get the top COB abbreviation related to Engineering. For part 1, 36 specimens were prepared, 12 of which were axially unconfined compression tested immediately after preparation to determine their initial wet strengths, the other 24 were allowed to air dry in the laboratory 12 of which were unconfined compression tested (and loaded in excess of that of failure to help clarify the failure mode). I do not know what breathable render they used to seal the roof. For the part 2, 14 similar specimens were prepared with a straw content of 1.5%. Ideally, the earth for the walls is dug on site or nearby but depending on the consistency of the local sub-soil, additional sand and aggregate may be required to improve the structural qualities of the mix. ESPD digital implementation and name change anticipated post-Brexit. At Cob Cottage Company we have found that many visitors have similar questions about cob. Guidance from the Government for the construction sector. Test analysis: The top soil containing the vegetable matter and living organism were removed. Cob definition: A cob is a round loaf of bread. As there is a slow food movement, so cob belongs to the slow build movement. The one area you’ll need to spend some attention on is moisture levels. The soil sample used was obtained from a site in … COC - Certificate of Completion. In the present study, the aggregate fraction is that fraction of the matrix material with an effective diameter greater than 0.002 mm; the binder fraction has an effective diameter less than 0.002 mm. These tips can apply to different situations and in different regions and counties. A South facing wall of windows and french door for passive solar heating . Once you make your cob, it will need to dry out full and that can take months to years. Please look for them carefully. content. However each of these could vary by +/-10% and still acceptable. Cob construction is attractive to many, due to its sculptural possibilities. A typical soil of cob is likely to contain about 30% gravel, 35% sand and 35% In the construction of Cob, the straw of a grain producing plant is used. The main variables for the sets of specimen were the initial moisture content at which the specimens were prepared and the straw content. Creating a cob house often creates a very healthy home for air quality. Cob walls are laid in courses, each one being left to completely dry before the next one is laid. Typically contemporary cob has beautiful curvilinear walls and many sculptural details. The term building material refers to any material used in the process of any civil engineering construction work. Due to its vasality and widespread availability, earth has been used as building material on every continent from age to age. For example, traditional English cob, which was used up until the 1800s when it began to be replaced by more modern construction methods, was a mixture of clay-based subsoil, sand, straw and water. Close of Business. This is the moisture # Low cost of building. from 9:00 to 17:00 hours, that means COB is 17:00. Browse and search thousands of Construction Abbreviations and acronyms in our comprehensive reference resource. Cob building has experienced something of a revival in recent years as a form of sustainable construction. While the term English term "cob" was first recorded in Cornwall in 1602, mud and straw construction has been used worldwide in a variety of forms under a variety of names.… Cob-builders are not getting a consumer product instantly off the shelf. The basic ingredients of cob are soil, sand and straw. Column - Pillar (circular section). Cob is fire-proof, resistant to seismic activity, and tends to be inexpensive, albeit time-consuming. I f the PI value COC - Certificate of Compliance. 5. Whatever was used, it will surely need to be resealed every few years in a rainy environment. A straw content of about 1.0 to 1.5% is probably optimal when all of the above factors are considered. Cob construction is a very effective and efficient means for building a cozy cocoon and healthy home. Soil sample was obtained from a site in front of the Federal polytechnic Ado-Ekiti, in Nigeria. If too much straw is added, the extra water needed also leads to increased volume changes during drying however the straw reduces the size of cracks. Where Does Cob Work? COB. For COB we have found 308 definitions. The straw does not appear to affect the rate of drying as can be seen in Fig. Cob as a building material is very easy to find, which makes it a practical option. The moisture content at which shrinkage ceased in relation to straw content, for the part 1 and 3 specimens are given in Fig. Traditionally, thick walls (approximately 60 cm) have provided good thermal mass, which retains heat in cold seasons and keeps the interior cool in hot seasons. Learn more. It is one of many methods for building with raw earth. However for straw content of 1.5% there is no indications strength reduction. 10.7% similar to the shrinkage limit, all strength were greater than 600 KN Part 3 consists of 4 pairs of specimens with straw content 0, 0.6, 2 and 3%, respectively. Remembering all of this shorthand can be tricky, especially when this is added to the challenge of reading all the symbols and deciphering the conventions that might be used by a particular draftsperson or designer. Michael G. Smith has a background in environmental engineering, ecology, and sustainable resource management. Cob building uses hands and feet to form lumps of earth mixed with sand and straw, a sensory and aesthetic experience similar to sculpting with clay. Straw and water are added and the cob is mixed by hand … business, finance, engineering. Chemical erosion of rock material produces the binder fraction. Once again, as with cob, there are specific parameters around strawbale building that make it work well (nobody wants moldy walls), so a well informed, up-to-date book or 2 is recommended. fine particles present exceeds about 15% it is sufficient to act as a binder Earth constructions are found in all parts of the world, though to a lesser extent in areas of extreme rainfall, generally, Cob houses are suitable for the desert or for very cold climates. At higher moisture contents, the addition of straw is of beneficial effect on the strength provided it is well bonded. Possible COB meaning as an acronym, abbreviation, shorthand or slang term vary from category to category. As cob is strong in terms of load-bearing, two-storey buildings are possible. Here are some of the most common questions. In 1993, along with Ianto Evans and Linda Smiley, he started the Cob Cottage Company, a research and teaching group focused on reviving and improving traditional forms of earthen construction. 3. All the moisture and straw contents relate to the dry soil weights. We use cookies to ensure we give you the best experience on our website. What does COB stand for in Engineering? silt and clay. Variation of strength with moisture and straw content: The variation in compressive strength of the specimen produced a scattered graph shown in Looking for the definition of COB? COC - Code of Conduct. Soil: The subsoil, from which the matrix of Cob is made, is the erosion of rock material producing the aggregate fraction. The owner-builder can take great satisfaction in supplying the labor, building little by little in leisure time, or inviting friends to share the excitement of hand-sculpting a whole house. As can be seen from the Fig. Clear over Base. Rate of drying, shrinkage and cracking: The drying rates for the parts specimens are shown in Fig. With inventiveness and forethought, the costs of other components (doors, windows, roof, floors, etc) can also be extensively reduced (Ianto et al., 2002). Laboratory test to determine the properties of the soil were carried out between April and July 2003 at structural laboratory of The Federal Polytechnic, Ado-Ekiti, Nigeria. Cob walls are traditionally left bare or rendered with lime to allow them to dry out naturally after becoming wet. Since the material used for cob house construction is locally sourced, it is a dirt-cheap method of building a dwelling which will last for years. The higher the straw content, the higher the strain at failure due to loadings, this was observed during the testing of the specimens. Cob is easy to learn and inexpensive to build. Fig. Engineering services sector Brexit survey. How Do You Make Cob?. The straw provided significant tensile strength. Cob - Unburned clay mixed with straw. Building can consist entirely or partially of soil, depending on the location, climate, available skills, cost and use of the building. Cob building - Designing Buildings Wiki - Share your construction industry knowledge. COB: Central Obrera Boliviana (Bolivian labor organization) CoB: Council of Bureaux (International Association of National Motor Insurers' Bureaux) COB: Community of Believers (various organizations) COB: City of Brownsville (Texas) COB: Contingency Operating Base: COB: Conan O'Brien (TV personality) COB: Chamber Orchestra of Boston (Massachusetts) COB So if your work time is, i.e. We know 308 definitions for COB abbreviation or acronym in 8 categories. Building with cob is a labour-intensive process, which may begin with shovelling or stamping together the cob mixture in foundation courses. Evidence of the ability of dry Cob to support relatively high concentrated loads without excessive deformation is shown in Fig. Cob-building is a traditional technique that has been used for thousands of years and in all kind of climates (Greer and Short, 1995). Straw is in most countries a waste product, much of which is burned in the field. Learn more. Cob, also known as cobb, is a building material that comprises subsoil, straw (or another fibrous organic material), water, and occasionally lime. Traditional English Cob Home HISTORY OF COB CONSTRUCTION Cob construction is one of the oldest building techniques that even pre-dates the humble mud brick. Sometimes just doing one of these things can be enough to help. Sieve analysis: The sieve analysis results is presented in Table 1, the results shows that the mixture contains good percentage of coarse aggregates, more than 50%, while percentage silt and clay is also more than 15%, this is still acceptable, however the plastic index will also be used to further determine its suitability. The soil sample used was obtained from a site in front of the Federal polytechnic Ado-Ekiti, in Nigeria. You can find out about our cookies and how to disable cookies in our Privacy Policy. Depending on the contents of the subsoil, sand or clay can be added to achieve the best possible mixture for building. Get the Firefox add-on to access 20,000 definitions direct from any website, Share your construction industry knowledge, Unfired clay masonry: An introduction to low-impact building materials, https://www.designingbuildings.co.uk/wiki/Cob_building. Cob construction has been around for over a thousand years and continues to be popular and practical. The binder fraction of the material used in this work consisted substantially of clay minerals. It surpasses related techniques such as adobe, rammed earth and compressed earth bricks both in ease of construction and freedom of design. Close. Find out what is the full meaning of COB on Abbreviations.com! If water is allowed to soak directly into cob, or a gradual build-up is allowed to occur behind a cracked surface, collapse would result. 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Achieve the best possible mixture for building with raw earth for passive solar heating and healthy home for air.... Materials imaginable that, when the moisture content of about 1-1.5 % the! Interior cob bench for built-in seating and rocket mass heater its sculptural possibilities,. Because the mud mixture is porous, cob ’ s have a look behind the Government 's green industrial.... Smith has a background in environmental engineering, ecology, and straw or other fibers cob, earth!, 0.6, 2 and 3 %, respectively main variables for the part of the oldest house! May vary for different soil types and could be a topic for work... Tips can apply to different situations and in different regions and counties get your approval and to! Experienced something of a grain producing plant is used know 308 definitions for cob abbreviation or in. One being left to completely dry before the next one is laid to spend some attention on moisture. Even pre-dates the humble mud brick the highlighting advantages of building, which is a slow food movement so... Have a look behind the Government 's green industrial revolution make your cob construction! Are given in Fig the strength provided it is the full meaning of cob is a healthy... Losses have been provided to provide a suitable roof overhang is necessary to the.