Company Portrait NEOPOR ® System GmbH has been on the world-wide market with CLC (Cellular Lightweight Concrete) for more than 30 years and responsible for the construction of well over 300.000 apartments and houses, as well as schools, hospitals and commercial buildings in over 50 different countries, utilizing NEOPOR ® equipment, foaming agent, fibres and of course NEOPOR ® technology. Buildings cast up to 25 years ago are evidence for the well ageing of CLC, using the same "ingredients" as in conventional concrete, namely sand, cement and water (gravel is large sand) and air, responsible for thermal insulation and weight reduction, embedded in our foam, which solely serves as wrapping medium and has no chemical reaction. Therefore CLC on its achievable level offers the same behaviour as convention concrete. As long as exposed to humidity in the atmosphere it will increase its mechanical properties (e.g. strength) infinitely. Using only sand, CLC preserves natural resources such as gravel and clay, both running short in many parts of the world and as in the case of clay even being prohibited from use for building components in an increasing number of countries (e.g. China) already. Natural resources are also preserved substantially by the high insulation properties of CLC, considering that it offers 500 % (!) and more insulation than conventional concrete. Whilst in cold countries insulation serves primarily against cold weather, protecting against heat (air-conditioning) requires another 500% more primary energy to cool down - certainly a large bill for any ones budget. NEOPOR ® CLC Cellular Lightweight Concrete (CLC) is conventional concrete, where natural aggregate (gravel) is exchanged for the best insulation medium available, namely air, embedded in an organic and bio-degradable foam that offeres no chemical reaction but solely serves as wrapping material for the air. Consequently CLC behaves, like conventional concrete, in particular concerning curing, hardening and most important "ageing ". CLC infinitely increases its strength by hydration (forming of crystals in cement) as long as exposed to humidity in the atmosphere. For structural (steel-reinforced) application, CLC is used in densities of 1.200 to 1.400 kg/m³, which, due to the billion of microsized and uniform air bubbles offer 500 % (!) more thermal insulation and a substantialy higher fire-rating than conventional concrete. If a wall of conventional concrete should offer the same thermal insulation as CLC, the wall produced would have to measure 5 times thicker and therefore also use 10 times more material (sand, gravel, cement) to produce. In hot environment the essential airconditioning requires 500% (!) more primary energy to cool down than when heating, a fact, which is not even known to many experts.
Lightweight concrete utilizing in excess of 25% of fly-ash Neopor cellular lightweight concrete (CLC) has been used in over 40 countries over the past 25 years to produce over hundred thousand houses and apartments, also schools, hospitals, industrial and commercial buildings. CLC is an air-cured lightweight concrete that can be produced at project site, utilizing equipment and molds normally in use for conventional concrete. The density recommended is 1.000 kg /m³ (oven-dried) for blocks and 1.200 kg/m³ to produce prefab elements and walls cast in-situ. The typical mix for a 1.000 kg/m³ density CLC to be used in blocks is as follows (to produce 1 m³) Cement (Portland): 190 kg = 61 liters Sand (0 - 2 mm or finer): 430 kg = 164 liters Fly-Ash: 309 kg = 100 liters (approx) Water: 250 kg = 250 liters Foam (neopor-600): 423 liters Wet density 1.179 kg/m³ Total volume (submerged in water) 1.000 liters (= 1 m³) Expected (oven-dry) density. approx. 1.000 kg/m³ Content of air in concrete approx. 43% Content of Fly-Ash in solid material (929 kg): 33% Content of Fly-Ash in oven-dry material: 31 % Benefits of CLC blocks/elements • • • •
Tremendous weight reduction High thermal insulation Optimum fire rating Substantial material savings: • no gravel used • little cement • less steel in structure and foundation • Easy and fast production • No primary energy and reduced transportation costs • Boon for remote areas with only sand available
CLC, like conventional concrete ages well, increasing its strength by as much as 50% (!) between 28 and 90 days after pouring, As long as CLC draws humidity from the atmosphere it will keep on increasing its mechanical properties. Only 1 kg (1 Itr) of Neopor-600 foaming agent is essen tial to produce 1 m³ of CLC for instance in a density of 1.200 kg/m³: A 200 kg/liter drum of Neopor lasts for more then 200 m³ of CLC. Neopor has a shelf -life of minimum 24 months.
Molds or design to produce inexpensive molds locally are provided by Neopor. Costing
Neopor customers undertook extensive co sting in different countries to evaluate competitiveness against conventional concrete blocks, clay - bricks and autoclaved aerated blocks on the finished wall. In particular if fly-ash is utilized, blocks of CLC often turn out to be the most competitive ones, also due to little equipment required (no block -making plant) can be produced on the site, saving transport and multi -handling. In view of fly-ash - an environment pollutant industrial waste - being a major ingredient of CLC, and this being a good substitute for ordinary clay bricks (which use high primary ENERGY and precious agricultural top - soil), the Government of India for instance has given special Import duty concessions. CLC is an excellent and competitive material for low -rise, load-bearing construction and outside walls as well as partitioning work in multi -storied blocks. Popular block sizes are:
600x200x200/100mm 500x250x200/100mm 500x400x100mm or as desired Blocks are cast in vertical position to offer equally accurate sides, given by the mold. Only one side (the top when cast) is not given by the mold as open-top, which is screeded. This side will face the next block in masonary anyhow. Curing of CLC takes place within the same period as conventional concrete. If cast in the evening, the concrete can be demolded next morning. Curing can be speeded up by either heat, steam or chemical (accelera - tors). - As in conventional concrete CLC may also be coloured (adding pigments).
Affordable houses cast in-situ in Indonesia in density 1.200 kg/m³ and wall thickness of only 60 mm. One house each day per each mold. Frames for openings (d/w) and facility tubes cast-in.
Light-weight block-production on site in India. Specially designed molds produced locally to Neopors specifications are assembled and waxed and poured with CLC density 1.000 kg/m³.
Demolding of blocks the day after casting or earlier it accelerated by either steam, heat or chemicals.
Shape and size of blocks are given by the molds. Blocks are sprinkled with water. Production and curing on the construction site to save transport and multiple handling.
Blocks are used for outside walls and partitions on highrise structure of conventional concrete.
Substantial weight reduction in high-rise by using CLC for multiple purpose (walls, floor screeds, balcony rails, bath rooms etc) saving tremendous quantities of steel in foundation.
Benefits of NEOPOR ® CLC Compared with conventional concrete, Cellular Lightweight Concrete (CLC) has many benefits. The tremendous savings described when using CLC are manifold, continuing with substantial savings in raw material (no gravel required), in dead load of high-rise reducing by almost half. Considering that a substantial amount of steel is necessary only to carry the weight of the structure, steel requirement might reduce by hundres of ton in high rise. is obvious in transport, where almost double of volume of building material can be produced, it has an impact on craning, where either larger panles can be taken, or the full capacity in span. Alternatively less re-location of the crane is necessary.
Weight reduction
increasingly turns to be the most important issue in the planning and construction of buildings. There are many costly ways of insulation on sandwich structure of a wall, adding the one or another rigid insulation material, with a satisfactory result by computation but not always a sound solution in safety, health or environment. The best solution is, to incorporate thermal insulation in the mix of a concrete, such offered in air cured CLC. Thermal Insulation
The air-embedded in the CLC is also instrumental for the high fire-rating . In 1200 kg/m³ density a 13-14 cm thick wall has a fire endurance of 5 hours. The same delay occurs with a 400 kg/m³ layer of CLC in only 10 cm thickness. CLC is otherwise noncombustible. Over the efforts to keep on increasing the thermal capacity of building members, other aspects have been neglected, such as sound insulation . Sound is experienced as air-borne or foot-fall sound (impact). Air-borne it is a rule of density and therefore CLC offers superior protection than very light concrete (ACC). In impact sound it is superior to conventional concrete. Hitting a wall with a hammer, will let you feel the full force on the other side, whilst the air embedded in CLC will not allow the blow to pass through. At the most it will suffer a small dent and thereby prevent any greater damage. As the impact force will not transmit, slabs produced of CLC or topped with a layer of CLC floor screed will prevent any sound being noticed in the room below. Walls of CLC will also serve as sound retaining walls on roads or railway tracks therefore, absorbing the sound and preventing it from bouncing to the other side. Adding fibers to CLC is a further important benefit, increasing bending stress substantially and most of it impact strength. The three dimensional acting fiber (e.g. polypropylene) will further reduce shrinkage, therefore reducing water absorption and increasing strength (up to 25 %. This is appreciated most when producing slender building components. Using only sand, cement, water and foam, the cost for one m³ of CLC in most cases is less even than for the equivalent volume of conventional concrete. Adding all the described highly appreciated benefits (comprising CLC) to regular concrete, if at all possible, the cost for such regular concrete would probably double but still not reach the overall quality of CLC. Our system can be readily integrated into existing concrete and prefab works, by just installing the inexpensive, simple but fully automatic foam generator. Over 300.000 buildings have been completed in the past 30 years in over 50 different countries, either using blocks of CLC, steel-reinforced prefab and slabs but mostly casting complete houses in one pour, using vertical formwork. This way one building is completed each day with every set of moulds, frames for doors and windows - or openings therefore, cast-in, the same as facility pipes/tubes for power and sanitary.
CLC becomes increasingly popular also in such countries, where the use of clay will be prohibited to conserve is for the agricultural industry only. A starter-kit is available for less than 10.000 Euro ex works. Required Equipment • • • •
MFG / MFG-A Foam Generator Conventional Mixers, pan-mixer, truck-mixer Conventional conveying system (buckets, Concrete pumps etc) Conventional moulds, horizontal/vertical
Raw Material •
Sand -2, -4, -6, -8 mm, depending on density and availability
Preference • • • • •
Washed River Sand min. 20% fines Cement, Preference Portland Water for Foam production: Potable Foaming Agent: Neopor-600/700
Optional • • •
Neofibre: Polypropylene Fly-ash up to 40% on total mix Lightweight Aggregate (e.g. expanded clay etc.)
Production Procedure Sand: Optimum properties are achieved when selecting the most suitable raw material
(Sand,Cement). Preference : River (round) sand, washed and with minimum 20% fines. Dust in sand increases the demand for water and cement, without adding to the properties. It also increases shrinkage. A certain, small amount (20%) of fines contributes towards strength. As in conventional concrete (CC), the sand should be free of organic material or other impurities. Crushed sand, due to sharp edges may destroy the foam mechanically. Portland cement is preferred over other cements, such as pozzolan. For Early stripping and optimum mechanical properties, high- grade (early strength) cement is recommended. Thick walls and when using battery-moulds, excess heat is developing within and might therefore ask for a lesser grade of cement. Remember : The slower the hardening, the better the final quality of concrete. Where economical, fly-ash may be added to the mix to substitute some of the cement. Fly-ash normally will retard hardening though. Cement:
When used to produce foam, has to be potable and for best performance should not exceed 25°C. Under no circumstances must the foaming agent be brought in contact with any oil, fat, chemical or other material that might harm its function (Oil has an influence on the surface-tension of water). The oil/wax used in moulds will not harm, since the foam by then will be embedded in mortar. Water to prepare the mix has to conform with general requirements for concrete
Water:
Foaming Agent: The containments holding foaming agent must be kept air-tight and under temperatures not exceeding 25°C. This way the shelf-life is guaranteed for 24 months from date of Invoice. Once diluted in 4o parts of potable water, the emulsion must be used soonest. (Diluted in 40 parts of water, Neopor 600 foaming agent is used by many as very effective fertilizer). Correct density of foam The weight of the foam should be minimum 80 g/l. Use a containment of as close as possible to 10 liters in volume, to check the weight (density) of the foam. Smaller containments might not allow to pour foam into, without possible large voids. A fast check on the correct weight is also possible by turning the bucket with foam up-side down. If the weight of the foam is minimum 80 g/l and does not drop out of the bucket, the consistency of the foam is correct. After several weeks of experience the person in charge of producing foam will know the correct quality of the foam by sight. Once set correctly, the foam generator will keep the consistency stable, as long as air-and watersupply remains constant as well. We still recommend to check the weight of the foam once in a week or if the density/consistency of the mix varies. Preparation of moulds For smooth surfaces clean moulds completely of remaining concrete, the steel/or wood surface must be oiled/waxed. Preference : Organic or vegetable oil/wax. Trials with different materials will have to show best results. Oil or wax will not destroy the mix, once the foam has been mixed in the mortar. Steel reinforcement will be placed in the moulds as usual. No coating of the steel is necessary – as in AAC (Syporex etc.)In panels of more than 12-15 cm thickness, we recommend the use of a double mesh (100 x 100 or 150 x 150 mm). The steel connected to the lifting anchors should reach more then half of the width of the panel and should possibly not be connected to the mesh. Ordinary steel is used as in CC when casting densities of 1200 or higher. The high ratio of cement to material in CLC ensures proper protection of the steel against corrosion. The steel embedded has to be covered by minimum 25 mm of concrete The use of spacers is recommended. To prevent cracking when lifting/tilting, steel rods may be placed across the anchors. A triangular strip of plastic or wood might be inserted along
the bottom edge of the mould – better also along the top, to prevent sharp edges, that might break of when handling and give the panels a poor appearance. Charging, Mixing and Pouring Before charging the mixer with material, it must be rinsed, in particular if the concrete produced before, used any additive, which might have adverse reaction on the foam. Where possible, start the mixer before charging it with material. If the sand contains excessive amount of water, the weight has to be adjusted, adding that much more sand as it contains water by weight, reducing at the same time the amount of water to be added to the mix. To obtain optimum performance, sand is first fed into the mixer, first absorbing water left after rinsing or from the previous (CLC-) mix. This way, the cement to follow will not clod, allowing best possible distribution in the sand. Keep on mixing, until a homogenous colour of the mix is achieved. If using Neopor-fibre, this is the moment it has to be added, mixing approx. 1 min. for each kg added, to allow the fibrillated polypropylene fibre to “open-up”. Check Neopor’s “Recommended Mix Design” for the recommended configuration of material to be used in different densities. The densities referred there-under are oven dry, achieved when drying the mix for 24h at 105°C. Before adding foam, the water/ cement (w/c) ratio of the mortar must be minimum 0,35. Lower ratios may cause the cement to draw water from the foam, causing it to partly or totally collapse, increasing the density and decreasing the yield. This is one of the most likely mistakes when learning how to produce CLC. Therefore, if one is in doubt, one should always add more, rather than less water. To a certain extend this might even increase initial strength. Doing the same with CC would definitely reduce strength, as excessive water causes voids when evaporating . CLC on the other hand consists of voids only. The weight of the foam should be minimum 80 g/l. Use a containment of as close as possible to 10 liters in volume, to check the weight (density) regularly. Smaller containments might not allow pouring foam into, without possible large voids. A fast check on the correct weight is also possible by turning the bucket with foam up-side down. If the weight of the foam is minimum 80 g/l and does not drop out of the bucket, the consistency of the foam is correct. After several weeks of experience, the person in charge of producing foam will know the correct quality of the foam by sight. Once set correctly, the foam generator will keep the consistency stable, as long as air-and water-supply remains constant as well. We still recommend to check the weight of the foam once in a week or if the density/consistency of the mix varies. Gravity mixers (e.g. Ready Mix) take the foam under almost instantly and distribute it homogenously in the mix. It takes more time to achieve a proper distribution when using pan-mixers or similar. In between pours, the mixer should be kept in motion until it is completely discharged.
CLC always should be poured in the shortest possible time. If buckets are used to fill moulds, they should hold as much CLC as possible, possibly even pouring one complete panel in one step. Extended time between pours of one building member might result in the creation of dry-joints as happening in the case with regular concrete as well. Although CLC does not require vibration - at least not to densify the mix - which is liquid anyhow, vibration of horizontally produced panels will show an even better surface, drawing cement slurry to the mould side. Preference is given to High-Frequency vibrators. Length of vibration 15-20 sec. or until bubbles on the surface appear in large numbers. Use aluminium or other straight and sharp-edged screedslats immediately after pouring the concrete. Delayed screeding might “smear” the surface. If moulds have to be moved after screeding, this might have to be repeated. Any disturbance of the freshly poured CLC during the setting process, might be harmful and cause part of it to collapse, in particular when the concrete is not hard enough yet to carry the weight and the foam has been weakened by loss of water, drawn by the cement already for setting. The poured building member should be covered, if possible, with a canvass or plastic sheet to keep the evaporating water on the surface. As with CC, hardening may be accelerated either by heating the moulds, steam or chemical (ask for details). Using most standard types of cement, panels may be lifted the day after casting. Due to the reduced strength in CLC, moulds should be tilted before lifting the panels. For the same reason panels of CLC should be handled with utmost care to avoid damage. Curing / Transport / Assembly Panels should be positioned upwards on the curing yard, resting on a soft underground best on a rake or wooden beams. All possible efforts should be taken, in particular in dry and hot climate or more even when windy, to keep the panels damp for at least three, bettor for more days. A sprinkler will be helpful or canvas that is kept wet. Curing compound would be the costly alternative. Standards call for a 24 day curing period for cement-based building members. Remember: Cement/Concrete only hardens with water or in a humid environment
Due to reduced weight, more volume of CLC building elements can be transported at the same (increased pay-load) then of CC. Panels should be kept upright during transport and also on a soft/wooden underground. Unload only in tilted position. Assembly
Assembly of panels in CLC happens usually the same way as with CC. Special care has to be taken not to apply any mechanical force to avoid damage. If necessary, panels of CLC may be sawn (no gravel), definitely nailed (without the use of dowels as in AAC), drilled or profiled. In densities of 1200 kg/m³ and higher, where reinforcement is used, CLC requires no special coating/plaster on the outside. Water-repellent paint (dispersion paint) will be suitable.
Vertical casting
The high fluidity of CLC allows full height walls or complete houses (floor by floor) to be cast in one pour, inclusive the slab. Frames for voids for windows, doors and other opening, or penings therefore are cast in place, together with empty tubes and pipes for power and sanitary. No voids, no sagging (beneath frames). Walls/ partitions may be as slender as 50 mm thick only (!) as no vibration is necessary. With a coarse sand paper stuck to a piece of board, rub the walls immediately after stripping, in circular motion, to eliminate possibly honey-web or “noses” caused by possible irregularities in the mould or by joints. Perhaps a day after stripping it is recommended to saw imitation joints from both sides of the walls on neuralgic positions to allow possible shrinkage to “accumulate” in the joints and not show on the walls, as also done in CC when casting in situ. Detailed drawings - according ICBO - upon request. As with all lightweight concretes (lesser with CC) hair-cracks might appear but have no adverse effect on the reintorcement, and usually disappear when painted. This way one complete house is cast each day with every set of vertical mould. Where applicable even the gable can be cast at the same time with appropriate modification to the mould (see attched photograph of a sample house by the largest manufacturer of cement in Africa PPC) Guidelines BRIEF GUIDELINES FOR MANUFACTURING, MASONING CLC BLOCKS AND MEASURES SUGGESTED TO AVOID & REPAIR CRACKS IN MASONRY (Kindly refer provisions of relevant clauses of IS: 6042 &IS:2572 for details) 1.0 Manufacture, Curing & Maturing of CLC Blocks
1.1 CLC slurry must be made using quality input raw materials {Portland Cement Grade 53, Clean river sand, Grade 1 Fly Ash, Clean water and Neopor Foam density 80 gms/litre} in defined proportions, mixed in a gravity mixer and poured into leak-proof battery moulds. 1.2 Blocks de-moulded on hardening are stacked, water spray cured for about two weeks like any other concrete product and then allowed to mature and get thoroughly dried till completion of 4-weeks after casting to enable their initial shrinkage to get completed, before being allowed to be used in masonry work. 2.0. Masonry Work & Plaster
(a) Masonry mortar should be leaner than the strength of block. As per provisions of Table-1 of IS: 2572; preferably 1-Cement, 1-Lime & 6-Sand. If Cement Sand mortar 1:6 is used then partial substitution of cement be done with Fly ash. (b) The blocks should be laid dry, but the surface on which mortar is being laid should be moistened to obviate it absorbing water from the mortar.
(c) Both horizontal and vertical joints should be ~ 10 mm thick. (d) The mortar shall be well spread on both horizontal and vertical surfaces of the joints to produce fully filled-up and well compacted joints. It may be necessary to add mortar especially to vertical joints to ensure ens ure that they are well filled. (e) The mortar shall be racked out of joints with a trowel to a depth of about 10mm as each course is laid to ensure good bond for plaster. (f) When the mortar has stiffened somewhat, it shall be firmly compacted with a jointing tool. The mortar shall be pressed against the units to affect intimate contact between the mortar and the masonry to obtain a water tight joint. Please refer two attachments reproduced from one of the referred IS codes. (g) Weldmesh ladder of 75mm width of 3 or 4mm Ø mesh of 25x75 mm rods be placed in every third course of 100mm thick partition walls. (h) Masonry shall be cured for at least 7-days and then allowed to dry before applying rendering over it. (i) Rendering of walls may be done with 1:1:6 Cement, lime, sand mortar or 1:4 cement mortar. When smooth finish is desired internally 2-3 mm thick lime neeru finish may be applied. (j) The masonry walls, abutting against structural elements like columns, beams may deflect, move because of load, settlement, shrinkage or thermal effects. In order to avoid cracking as a result of such movements, a slip joint shall be provided, preferably packed with a resilient material. (This could be material like “Sika Flex Construction”, “Dr. Fixit Crack-X etc.) If, however, no joint line is desired to be seen at the junction of columns and beams with masonry from aesthetic considerations, then the junction, as treated above may be over laid with a 200mm wide chicken mesh, equally spaced on either side of the joint line, before rendering the wall with plaster. 3.0 Observation of cracks and Remedial Measures
It is felt that deficiencies in observance of broad stipulations stated under 1.2, 2(a) to 2(g) etc. above have resulted in appearance of some cracks at some locations in the plastered walls. The types of cracks seen are: 3.1 Hair cracks in Putty finish: -
Some hair cracks have been observed at isolated locations in the putty finish. We concur with the assessment of your Chief Project Manager, that these are only in the putty layer
and do not extent into the plaster. (It is likely that if use of cement based putty or Neeru finish is adopted, such a situation may not occur). However in the current situation, it is suggested that the joint be cleaned of dust, removing any flaky material, moisten the surface slightly paint with a brushable consistency paste of 1 part Sika Latex & 1 part Cement. Alternatively apply with a putty knife a mix of 2.5 parts Dr. Fixit Crack-X powder mixed with 1 part water by volume, remove excess material and let it stay for 24 hours before paining. 3.2 Crack at some masonry junction with Beam/ Column or other locations.
3.2.1 The joint between the structural elements and masonry be treated as stated under 2(j) above. Make a 6x6-8 mm groove along the line of joint with a grinder, clean and wash with water and fill the groove with “Sika Flex Construction” or equivalent polyurethane single compound sealant. 3.2.2 Isolated cracks in the body of the masonry be also opened-up into grooves of 6x6-8 mm with the help of grinder, cleaned and washed and then filled up with a putty made of : •
•
•
2-Sika Latex + 5-Cement+ 15 Sand and water over a primer coat, if recommended by Sika. or Dr. Fixit Crack Filler and Water in volumetric proportion 2.5 to 1. or 1 Bond Aid (of Asian Laboratories, Okhla) :2 parts water mixed with equal amount of Cement and twice the quantity of Sand.
(Note: A typical sample repair work, noticed at one location, done by some agency by making 200-250 mm wide repair bands over the crack locations, is un-called for and would be wastage of costly input materials). General: •
•
It was learnt that all plaster work is being done using Recron fibre as additive. However it does not seem to be effective. Use of Polypropylene fibre could be tried as a better alternative. Use of any kind of bond aid (to the extent of 2% -3% of cement content) as an additive in the masonry mortar could improve bonding efficiency and reduce water requirement for hydration.
Our Assistance
We can render you assistance to: a. Enable Enable you to obtain obtain the the first first “Concessiona “Concessionall Duty Certificat Certificate” e” from appropria appropriate te Govt. authority for the import of Foaming Generator and the Foaming Agent at highly concessional custom Duty as per prevailing EXIM policy of Govt. of India. (Note: The subsequent concession letters for future imports of Foaming Agent could be obtained by you your-selves based on the experience of the first letter). b. Guide you you in selectio selectionn of proper proper quality quality of fly fly ash and guiding guiding you with with your your initial laboratory trial mixes to arrive at over 25% Fly Ash consumption mixes for different densities of CLC production. c. Provide you basic basic drawing drawing for manufact manufacture ure of steel steel battery battery moulds moulds by your-sel your-selves ves for the production of pre-cast CLC blocks of desired size and density. d. Issue guidelin guidelines es for productio productionn of good qualit qualityy CLC and proper mainten maintenance ance of equipment and ensuring quality production and control of CLC with a small laboratory set-up and daily/ weekly/ monthly control schedule. & e. Organize, Organize, if so desired desired by you, you, deputati deputation on of an an Indian Indian Specialist Specialist for commissioning of your imported Foam Generator and training of your personnel in its operation, use, maintenance & quality production of CLC. This could be a better and more cost-effective alternative to your depending on a foreign expert from NEOPOR, Germany. Our fees for the services covered under (a) to (d) above is Rs. 30,000/- only (plus 8% service Tax), with 50% payable in advance and the remaining amount being paid on your having been issued the requisite concessional duty certificate from the appropriate authority. The commissioning Engineer, if sought by you as per (e) above, shall be reimbursed his travel costs, provided local hospitality and transport plus Rs. 3,500/- per day for the days of his absence from New Delhi Different Methods for producing Blocks of air-cured Cellular Lightweight Concrete (CLC) Applicable Standards:
DIN 4232, 4219 Lightweight Concrete DIN 1048 Testing Methods DIN 4164, 4165, 4166 ACC/CLC 4223, 4226, 18 152 DIN 4102 Fire Rating DIN 4108, 52.612 Thermal insulation DIN 4149 Seismic DIN 18.152 Solid Blocks DIN 50.017 Water Condensation… DIN 52.104 Freece-Thaw-Cycle
DIN52.615 Water Vapor Permeab. DIN 53.420, 50.014 Determ. of Density For the production of blocks in air-cured cellular concrete Neopor recommends a mini-mum density of 1.000 kg/m³ (oven-dry). This is to safeguard that the blocks produced offer: • • • •
Sufficient strength Affordable shrinkage Affordable strength Affordable water absorption
Utmost care has to be taken on the only solid used in CLC (besides binder), namely the sand. As ruled in general standards for any type of concrete, it has to be free of any contaminationand in sieve according to our attached sample. Generally it is recommen-ded not to use crushed sand, which tends to crush the foam when agitated (mixed). A special method of even using crushed sand has been patented and is under trial. To warrant best distribution of the foam in the shortest possible time, the use of gravity mixers is recommended, ensuring, that the mix is more than 60% of the total volum of its total capacity after adding the foam. To ensure optimum strength, it is recommende to first charge the mixer with sand, until the remaining mix/water left from the previous mix has been absorbed, before adding cement. When a homogeneous dry mix had been obtained, the recommended amount of water is been added. Make sure, that sufficient water had been added, as otherwise the cement in the mix will draw its shortcomings from the water in the foam, causing the latter to collapse partly or totally. There is no fear of taking too much water, as the W/C ratio does not play the role as in conventional concrete, reducing the strength. Too much water in CLC prima-rily prolongs the hydration process but has no negative reaction on the strength to be achieved. Moulds used have to be waxed/oiled befor pouring CLC to allow easy stripping and smooth surfaces. Care has to be taken in selecting the most suitable wax/oil to allow adhesion of later-on painting or plastering. Where “green-strength” of CLC is required to cut larger cakes into desired dimensions, a special tool is available to mechanically determine the suitable time of cutting by wires. A typical mix design per 1 m³ of CLC for blocks in density 1.000 kg/m³ (oven-dry) is as follows:
Sand up to 1mm, maximum 2 mm : 560 kg Cement (Portland) : 350 kg Water in mix : 120 ltrs + Stable Foam : (560 ltrs) Water in foam ( use potable water for ~) : 5 ltrs
Wet density : 1.075 kg/m³ Oven-dry density : 1.000 kg/m³ Hydration/hardening of CLC can be reduced by either using high early strength cement, warm water (heat, steam) or else chemistry.
Acceleration:
If not accelerated (see above), the moulds are normally stripped the day after pouring, cleaned, assembled and waxed/oiled, before pouring again. Stripping:
Curing/herdening after stripping is best done by keeping the blocks moist for minimum 7 days after, preferably even longer, storing the stripped blocks under canvas, which is constantly kept moist. It is recommended alternatively, to wrap the stack of blocks into plastic foil immediately after demoulding ((if possible use shrink foil), to keep the moist-ure within as long as possible, keeping hydrating /crystallizing/hardening. Treatment:
Paint/Plaster (Stucco):
When using paint only, we recommend a water repelling quality. Otherwise, different methos are been applied in different countries. Mortars are prepared in a variety of qualities as for instance: • • •
Combination mortar of cement plus lime plus sand ( 1 : 1 : 6) Or else 0,8 parts of cement – 0,2 parts of fly-ash plus 6 parts of sand Or else cement plus sand mortar reinforced with say 0,5 kg/m³ of polypropylene fibres.
Some also use ladder reinforcement every alternate layer of partition wall masonry. Others consider it best, if the joint line between the structural frame columns and beams is defined after plastering work, as this is the location where cracks, if any, appar lateron. The joint under the beam and the top of the masonry wall should prefearably be sealed with some kind of sealant after the total structural elements are fully loaded with masonry walls from above (the next floor). Generally care has to be taken, that the mortar used will develop less strength than the blocks to be layed on mortar. Further details are available to our clients upon request. Range of densities Density 100 kg/m³
NEOPOR ® offers the only system world-wide to produce a solely mineral-based insulation board offering the same lambda as man-made polystyrol, poly-urethane or
mineral wool, however without any hazardous behaviour for health, environment or fire. This density requires autoclaving. Complete plants are available to produce up to 500 m³ daily (or more). Density 300-600 kg/m³
This density is primarily applied for thermal insulation or fire protection. It uses only cement (or little sand), water and foam and can easily be pumped. NEOPOR ®'s foam generators allow the production of stiff foam for slopes to be applied on roof-tops. Density 700-800 kg/m³
Is also used for void-filling, such as an landscaping (above underground construction), to fill voids behind archways and refurbishing of damaged sewerage systems. It is also been used to produce building blocks. Density 900-1100 kg/m³
Serves to foremostly produce blocks and other non-load bearing building elements such as balcony railings, partitions, parapets and fence walls etc. Density 1200-1400 kg/m³
Are the most commenly densities for prefab and cast in situ walls, load-bearing and nonload-bearing. It is also successfully used for floorscreeds (sound and insulation plus weight reduction). Density 1600-1800 kg/m³
would be recommended for slabs and other load-bearing building elements where higher strength is obligatory.
Recommended Mix Designs Recommended Mix Design to produce 1 m³ of CLC
Equipment Minimum investment: As conventional concrete and prefab plants may be used to produce CLC, the only investment would be for the inexpensive foam generator and generator and the foaming agent. agent. Foam generators NEOPOR ® System GmbH offers two types of Foam Generators. The BK-8 has an integrated air compressor. The MFG-A is delivered without an air compressor.
Foaming agent NEOPOR ® foaming agent is based on a protein-hydrolisation. It causes no chemical reaction but serves solely as wrapping material for the air to be encapsuled in the concrete (mortar). It is bio-degradable and some of the clients even use it as a fertilizer for plants.
Concrete technology Raw materials Mixing and poring Hydration process Curing Treatment
Properties and behaviors Research & Development (R&D) Building Technology why use clc light weight bricks in construction?
for more information:foam information:foam generator Why use clc light weight bricks or foam concrete bricks? Clc is cellular weight blocks where we can use for load bearing structure and frame structure .its a other alternative for red brick and fly-ash bricks.Why we use clc bricks? 1)Clc is a light weight brick where water absorption is less compare to redbrick and fly-ash brick 2)High thermal insulation 3)Compressive strength is more than other bricks 4)environmental friendly 5)Quantity of cement is less when making a wall why because 6) clc bricks life span is more than other bricks Clc block size can make according to our requirements In India generally block can make Clc Size per cubic meter 4*8*24
83 clc blocks
6*8*24
55 clc blocks
9*8*24
50 clc blocks
If we take one clc block size red bricks comes around for each clc block 4*8*24 7.1 6*8*24 10.6 How we compare clc bricks with red bricks when we meet customer ? If we take the size 4*8*24 market price now in India is 3500Rs per each cubic meter Red bricks market price now in India is 2357Rs per each cubic meter its varies city to city . So the first question comes from customer why i spend more money for clc bricks?
Here is the solution Take an example: 1 unit wall brick construction with clc and red brick Clc bricks for 1 unit wall construction red bricks for 1 unit wall construction Clc bricks for 1 unit wall construction Red bricks for 1 unit wall construction 1) clc bricks for 1 unit wall around 75 bricks 1) red bricks for 1unit wall comes comes around 560 bricks 2) quantity of cement and sand requires for motor 1unit wall cement : 1 bag cement sand : 4bag sand price : 300Rs for cement 100 Rs for sand ---------------------------------Total 400 Rs/----------------------------------- 2) quantity of cement and sand requires for motor 1unit wall cement : 2.5 bag cement sand : 10 bag sand price : 625 Rs cement 250 Rs for sand ---------------------------------Total 875 Rs /----------------------------------3) Plastering: ½ inch plastering is Enough Cement : 1.5 bag cement Sand : 6 bag sand Price : 450 Rs for cement 150 Rs for sand ---------------------------------Total 600 Rs/----------------------------------- 3) Plastering: 1.5 inches plastering is needed Cement : 3.5 bag cement Sand : 14 bag sand Price : 940 Rs for cement 350 Rs for sand ---------------------------------Total 1300 Rs/----------------------------------Total cost for plastering and motor joints For clc bricks 600 + 400 = 1000Rs Total cost for plastering and motor joints
For red bricks 1300 + 875 = 2175Rs Red bricks for 1 unit wall price is 4 * 560 = 2240RsClc bricks for 1 unit wall price is 45*75 =3375Rs If we subtract clc price from red brick price 3375 2240 -----1135 Now add plastering and motor joints price Ie 2175 1135 --------3310 --------So at the end of the 1 unit wall construction the price we are spending for red bricks as almost same as clc bricks apart from that contractor can construct the building less time then red brick construction. So finally customer can happy To get good product in the market to build is home Note : The above calculation we are giving for construction a building with clc its varies cities and cities . -- Srinu Vuggina, Vuggina, November 24, 2011 Contribute a response Responses why use clc light weight bricks in construction?
Srinu, is "clc" a brand name or an abbreviation for the material used? -- Frank John Snelling, Snelling, November 30, 2011
What is CLC Cellular Lightweight Concrete (CLC), is a version of lightweight concrete that is produced like normal concrete under ambient conditions. It is produced by initially
making a slurry of Cement + Fly ash (Optional) + Sand + Water, which is further mixed with the addition of pre-formed stable foam in an unique Foamed concrete mixer. The mixture is either poured or pumped into assembled moulds of bricks or form-work of reinforced structural elements or poured onto flat roofs or voids for thermal insulation or filling. The foam imparts free flowing characteristics to this slurry due to ball bearing effect of foam bubbles enabling it to easily flow into all corners and compact by itself in the moulds/forms without requiring any kind of vibration or compaction. Cellular Light Weight Concrete (CLC) technology has been used in over 45 countries of the world over the past 30 years to construct Over a hundred thousand houses, apartments, schools, hospitals, industrial, commercial buildings etc. The introduction in India of a modified version using over 40% fly ash has made it an even more eco-friendly and cost effective version of CLC. The new product is set to revolutionize the manner in which buildings are constructed. In the process, the product brings quality housing closer to the masses at a faster and at a lower cost.
CLC Bricks Cellular Lightweight Concrete (CLC) bricks are environment friendly and manufactured from common natural raw material. The energy consumed in the production process is only a fraction compared to the production of other materials and emits no pollutants and creates no toxic products or by products. The CLC bricks that we offer provides thermal and sound insulations and also fire protection eliminating need for many layers of plastering and do not emit any toxic gas when exposed to fire. These bricks are highly strong and of customized shape thus requiring less amount of cement and plastering and giving an even shape to the construction.
Brickwell’s manufacturing unit located at multiple cities, supplies CLC Bricks to residential, commercial and industrial real-estate developent projects across India.
Brickwell’s wholly owned manufacturing unit can produce CLC Bricks as per standard industrial sizes or tailored for your specific requirements. CLC Bricks are available in 3 grade strengths: •
•
•
Grade A: These are used as load bearing units & have a brick density in the range of 1,200 kg/Cum – 1,800 kg/Cum Grade B: These are used as non-Load bearing units & have a brick density in the range of 700 – 1,000 kg/Cum. Grade C: These are used for providing thermal insulation & have a brick density in the range of 400 – 600 kg/Cum.
Technical Specifications of CLC Bricks:
Technical Specifications of CLC Bricks Brick Size (mm)
600 x 200 x 200 600 x 200 x 150 600 x 200 x 100
Approximate Weight/Brick (Kg)
No. of Brick/Truck
No. of Bricks/Cu.Mtr.
20.500
3 05
41
15.500
4 16
55
10.250
6 10
83
Grade wise comparison of CLC Bricks:
Grade-wise Technical Comparison of CLC Bricks Type Type Densi Density ty Min. Min. Compre Compressi ssive ve Stren Strength gth N/m N/mm2 m2 Water Water Absor Absorpti ption on %
Grade A 1800 160 0 1400 1200 Grade B 1000 800 Grade C 600 400 • • • • •
25.0 17.5 17 12.0 6.5 3.5 2.5 1.0 0.5
7.5 7.5 10.0 10.5 12.5 12.5 15.0 15.0
What is CLC? Advantages of CLC Comparison of CLC with traditional building materials Insulation / Flooring / Roofing using CLC Discover foaming agents by Isoltech Italy
Cutting Machine developed by Brickwell
Advantages of CLC Advantages of CLC Bricks •
• • • • • • • •
• • • •
• •
CLC Bricks have excellent compressive strength in excess of regular clay bricks / solid blocks, guarantees min. Compressive strength of 3N/mm2. Bending strength is 15 to 20% of compressive strength. CLC Bricks density is 800kg/m2 which reduces dead load on structures. Huge saving in foundation and structure savings upto 30% on beam costs. Good earth quake resistance properties. Easy handling. Faster construction. Huge saving of labour. CLC Bricks offer highest thermal insulation making cool summers and warm winters. Reduced Air conditioning expenses. CLC Bricks are fire resistant. Non toxic fumes in case of fire. Excellent acoustic barrier. More peace of living, No disturbance from your neighbours home theatre. Highly accurate and smooth walls reduction in plastering. Opt for any finish on walls – external plastering, tiling, cladding, internal tiling, dry lining, spray plaster or anything of your choice.
Comparison of CLC S. Para Param meter eterss No.
Cell Cellul ular ar Ligh Lightw twei eigh ghtt Concrete Bricks
Autoclaved Aerated Concrete/Ho Burnt Clay Concrete Blocks llow Bricks
Concrete Blocks
Basic raw Cement, Sand, Aggregate, Cement, Cement, Sand, Fly Ash 1. materials & Fly Ash, Water & Foaming Sand & & Acration Compound other inputs Compound Aggregate 2.
General Properties
Dry Density kg/m3
1200650 75 0 1200-2400 1800 125Compressiv 40-60 20-30 180 e Strength (Grade 35 40 30-60 (Grade A) (Grade 3 in kg/cm B) C) Reinfor Range of Non-load Non-load ced Reinforced applications Insu Insula lati tion on Parti Partiti tion on bearing Bearing element panels / utility blocks Walls s No gain in No gain in strength Aging Gains strength with age strength with with age age 0.132-0.151 for 800 kg/m3 Thermal 0.132-0.151 for 650 Conductivit kg/m3 y (W/m.k.) 0.238 for 1000 kg/m3 Sound Superior than burnt clay & Superior than burnt Good Insulation hollow concrete clay & hollow concrete Ease of Can be cut, nailed & Difficult to Can be cut, nailed & drilled Working drilled work 3.
Top Soil & Energy
400
8001000
1 900 40-125 Load-bearing & non-load bearing No gain in strength with age 0.184 Normal Normal
Shape & Form
Pre-cast 600 x 200 x 100/200 600 x 200 x 100/200 mm Brick size mm Pre-cast Any size of of elements Any si size of of el elements elements Cast in Any shape & size in any Not feasible shape density Water 12% for 800 kg/m3 density (by volume) Absorption 4. 45% by volume % by weight 7.5% for 1800 kg/m3 density 5. Drying 0.05 Grade A Shrinkage after Shrinkage maturing
400 x 400 x 230 x 100 x 70 100/200 mm mm Not fe feasible Not feasible Not feasible Not feasible 20% by volume
20% by volume
0.07 (M-25 No shrinkage Concrete)
0.011 (for 1200 kg/m3)
mm/meter 6. Productivity
0.10 Grade B Output 100% more than brick work Pollution free
0.058 (for kg/m3) Output 100% more than brick work
50% higher than brick
Creates smoke
Pollution free High energy requirement
Normal
Medium energy
Eco Least energy requriement 7. Friendliness No smoke Can consume fly ash around Open process uses fly 33% ash 55% reduction in weight of walls.
Uses high energy Wastes agricultural land
55% reduction in weight of Structural walls. saving due Marginal Tremendous structural 8. to dead dead weight No additional Tremendous structural saving for high rise weight reduction saving for high rise buildings buildings in reduction in Earthquake / Poor soil area Earthquake / Poor soil area
CLC Flooring
Brickwell CLC is used for roofing and flooring applications extensively.
A low density mix is chosen and the resulting air content gives the material excellent thermal insulation properties. The low density also has the advantage that it does not significantly add to the overall weight of the roof. Foamed concrete has two benefits when it is used for roofing. The first benefit is that it provides a high degree of thermal insulation. The second benefit is that it can be used to lay a flat roof to falls, i.e. to provide a slope for drainage. Foamed concrete is also much lighter than slopes made from mortar screeds. This means that a roof with a slope made of foamed concrete imposes a lower loading on the structure of the building. CLC can be produced and poured for floors and roofs on-site. In roofs it can be used because of very good insulation properties and it is comparatively lightweight. For floors CLC offers faster installation and a less expensive option because of the flowing and self-leveling properties.
Foaming Agents For the production of cellular concrete, Brickwell has tied up with Isoltech, a world leader in CLC Manufacturing Solutions. Brickwell offers to its clients the quality and effectiveness of the foaming agents ISOCEM S/L and ISOCEM S/B-P. ISOCEM S/L
Isocem S/L is a foaming agent for cellular concrete, developed by Isoltech. The properties of cellular concrete obtained by using the specific foaming agent Isocem S/L, however, are influenced by the foam/cement ratio, rather than by the properties of the foam itself, and this ratio determines the final heat and sound insulation properties ot cellular concrete. ISOCEM S/L is an innovative foaming agent, made up of natural surfactants mixed to vegetable raw materials: it is highly effective and can also be used as an air-entraining additive for cement mixes containing light aggregates (EPS, vermiculite etc.).
Physical Properties:
The most significant physical property of cellular concrete is its density. It is determined by the quantity of air in a cubic meter of material, that is by the air/cement ratio. The most frequently used densities are:300 kg/m3400 kg/m3500 kg/m3600 kg/m3 These densities correspond to different values of thermal insulation and mechanical resistance, which approximately amount to the values in the following tables: • • • •
D 300 kg/m3 = 0.062 kal/m/h/C° D 400 kg/m3 = 0.08 kal/m/h/C° D 500 kg/m3 = 0.09 kal/m/h/C° D 600 kg/m3 = 0.12 kal/m/h/C°
Doses: 2.5-3% (percentage of foaming agent for the production of cellular concrete).Applications: layers and/or sloping terraces. Storage: 1000 kg tanks or 200 kg drums. Description and Features: Isocem S/L is a foaming agent for cellular concrete, developed by Isoltech. Its main features are the following:
Isocem S/L Description Physical properties properties Isocem S/L
Appearance Colour Density PH Freezing point
liquid light brown 1025 g/l 7 -2 °C
ISOCEM S/B-P
ISOCEM S/B-P is a foaming agent made up of protein hydrolysates, which form a highly stable foam; it is used to produce building blocks with specific foam generators and can be used in all medium density mixes of cellular concrete and sand, from 600 to 1200 kg/m3. Properties: •
Absorption: Trials have shown that the foaming agent ISOCEM S/B produces a cellular concrete with very low water absorption. The higher the air content, the higher the water absorption: a fully submerged, medium density (770 kg/ m3)
•
•
•
•
•
•
•
•
•
•
•
sample of cellular concrete absorbs only 13% of the weight of water over a 10 days period. Fire resistance: Cellular concrete is extremely fire resistant and well suited to applications where fire is a risk. Tests have shown that in addition to prolonged fire protection, the application of intense heat, such as a high energy flame held close to the surface, does not cause the concrete to spall or explode as is the case with normal weight concrete. Reliability: Foam concrete is not subject to the impact of time: it does not decompose and is as durable as rock. Its high compression resistance allows to use it with volumetric weights that reduce the global weight of a building. Heat: Due to a high temperature lag, buildings made of foam concrete are able to accumulate heat, which allows to minimize heating expenses by 20-30%. Microclimate: Cellular concrete prevents loss of heat in winter, is moisture resistant, allows to avoid very high temperatures in summer and control air humidity in a room by absorbing the output of moisture, thus helping to create a favourable microclimate (like in a wooden house). Quick mounting: The small density (and therefore the lightness) of foam concrete and the large size of blocks compared with bricks allow to increase the speed of laying by several times. Foam concrete is easy to process and trim, to cut channels and holes for electrical wiring, sockets, and pipes. The simplicity of laying is reached through high exactness of linear dimensions: the tolerance is +/- 1 mm. Sound insulation: Cellular concrete has a relatively high property of acoustic absorption. Buildings made of porous concrete meet the requirements for sound insulation. Environmental compatibility: During maintenance, foam concrete does not produce toxic substances and in its ecological compatibility is second only to wood. As a comparison, the coefficient of ecological compatibility of porous concrete is 2; of wood 1; of brick 10; of expanded clay 20. Versatility: Due to its high workability, it is possible to produce various shapes of corners, arches, pyramids, which can enhance the architectural and aesthetic value of buildings. Cost-effectiveness: The high geometrical exactness of dimensions of concrete production allows to lay blocks on glue, to avoid “frost bridges” in a wall and to make inner and outer plaster thinner. Cellular concrete weighs from 10% to 87% less than standard concrete. A sufficient reduction of weight leads to a sufficient economy on basements. Safety: Foam concrete is protected from fire spread and corresponds to the first degree of refractoriness. Thus, it can be used in fire-proof constructions. Under the impact of intensive heat, like that of a blow lamp, the surface of foam concrete does not split or blow, as is the case with standard concrete. As a result, the armature is protected from heating for a longer period. Transport: The compact size of systems and their low cost allow to distribute them near the target markets, thus saving on transport costs.
Isocem S/B Comparison
Density Density (kg/mc) (kg/mc) Cement Cement kg Sand kg Water Water l. Isocem Isocem S/B kg
6 00 8 00 1 000 1 200
3 10 3 50 3 70 4 00
2 10 3 70 56 0 75 0
1 10 1 20 1 25 1 40
0.9 0.8 0.7 0.65
Isocem S/B Properties Thermal density (kg/m3) Mechanical Mechanical resistanc resistancee Insulation Insulation
6 00 8 00 1 000 1 200
1.2 2.0 3.0 4.5
0.12 0.21 0.24 0.38
IN THE PRESENT SCENARIO WHERE CONSTRUCTION IS AT PACE THESE CELLULAR LIGHT WEIGHT CONCRETE [C.L.C] BLOCKS SAVES TIME AND MONEY.THE THERMAL INSULATION PROPERTY OF THE CELLULAR LIGHT WEIGHT CONCRETE BLOCKS SAVES ELECTRICITY COSTS.WHO ARE INTERESTED TO SET UP NEW C.L.C INDUSTRY PLEASE MAIL US AT
[email protected] OR CALL US AT 09581563999,916036399,9885263999 ==============================================
