Cement production process, limestone and clay as the main raw material, crushing, ingredients, made from finely ground raw material, cement kiln feed material calcined maturity, adding appropriate amount of gypsum (sometimes mixed with mixed materials or additives) Ground made.
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Cement classification
2.1 Cement-use and performance is divided into: (1) Common cement: General civil construction commonly used in cement. Universal Cement mainly refers to: GB175-2007 cement under the six categories, namely, Portland cement, ordinary portland cement, slag cement, pozzolana cement, Portland cement and fly ash composite Portland cement. (2) special cement: a special purpose cement. Such as: G-class oil well cement, Portland cement road. (3) characteristics of cement: a performance of the more prominent cement. Such as: rapid hardening Portland cement, low heat slag cement, aluminate cement expansion of sulfur. 2.2 cement its name into the main hydraulic material: (1) Portland cement, Portland cement is known abroad; (2) aluminate cement; (3) sulfur aluminate cement; (4) iron aluminate cement; (5) Fluoride aluminate cement; (6) volcanic ash or other potential water-rigid material and active material as the main component of cement. 2.3 The main technical features are divided into: (1) fast hard: hard and fast express is divided into two types of hard; (2) heat of hydration: divided into two types of heat and low heat; (3) Sulfate resistance: points in the corrosion resistance and high resistance to sulfate corrosion of two types of sulfate; (4) expansion: expansion and self-stress is divided into two categories; (5) high temperature: the temperature of the aluminate cement, alumina cement content classification. 2.4 Cement naming principles: Named according to different types of cement were the main hydraulic cement minerals, mixed materials, use and main characteristics, and as concise and accurate, the name is too long, allowing a short title. Universal cement to cement the name of the main hydraulic mineral known as hybrid or other appropriate material named name. Dedicated special-purpose cement its name and goes by different models. The main characteristics of cement with cement hydraulic cement mineral name the main features of branded name and goes by different models or composite name. To potential water or ash and other hard materials, active materials as the main component of cement is the name of the main components of the name of active materials known to be named, the name can also be re-branded properties, such as slag cement, gypsum, lime ash cement and so on. 2.5 Cement type definition (1) cement: mixing water into a plastic paste, can be cemented sand, stone and other materials, but both in the air hardening hardening of the powder in water hydraulic cementitious material. (2) Portland cement: Portland cement clinker by the 0% to 5% limestone or granulated blast furnace slag, the amount of water made of finely ground gypsum hard cementitious material, known as Portland cement, sub-PI and P. II, that is known outside of Portland cement. (3) Portland cement: Portland cement clinker by the 6% to 15% mixed materials, made of finely ground gypsum moderate hydraulic cementitious material, known as ordinary Portland cement (referred to as ordinary cement) , Code: PO. (4) slag cement: from Portland cement clinker, granulated blast furnace slag and the amount of plaster made from finely ground hydraulic cementitious material, called slag cement, Code: PS. (5) pozzolana cement: from Portland cement clinker, pozzolana mixture of finely ground gypsum material and the amount of water made of rigid cementitious material. Called pozzolana cement, Code: PP. (6) fly ash cement: from Portland cement clinker, fly ash and the amount of plaster made from finely ground hydraulic cementitious material, known as fly ash portland cement, Code: PF. (7) portland cement: from Portland cement clinker, two or more provisions of the finely ground mixture of materials and the amount of plaster made of hydraulic cementitious material, called composite portland cement (the composite cement), code-named PC. (8) heat Portland cement: the appropriate component of Portland cement clinker, by adding appropriate amount of gypsum made from finely ground with moderate heat of hydration of hydraulic cementitious material. (9), low heat slag cement: a proper component of Portland cement clinker, by adding appropriate amount of finely ground plaster made with low heat of hydration of hydraulic cementitious material. (10) rapid hardening Portland cement: Portland cement clinker by the amount of gypsum added, made of finely ground high early strength that label with 3-day compressive strength of cement. (11) sulphate resisting Portland cement: Portland cement clinker by the added amount of finely ground plaster made good resistance to sulfate corrosion of cement. (12) white Portland cement: from iron oxide by adding a small amount of Portland cement clinker, gypsum, ground made of white cement. (13) Road Portland cement: Portland cement by road proficiency, 0% to 10% active mixture of finely ground gypsum material and the amount of water made of rigid cementitious material, known as Portland cement road, (the road cement). (14) masonry cement: mixing the active material, add appropriate amount of Portland cement clinker and gypsum, mainly for mortar made of finely ground low-grade cement. (15) oil well cement: the proper mineral composition of Portland cement clinker, gypsum and the amount of finely ground mixture of materials made for a certain well temperature conditions, oil and gas wells cementing engineering of cement. (16) gypsum slag cement: the granulated blast furnace slag as the main component material, add appropriate amount of gypsum, Portland cement clinker or lime made of finely ground cement.
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Cement production process
水泥生产工艺
水泥生产工艺
3.1 Production Methods Silicate cement production process in cement production representative, is composed of limestone and clay as the main raw material, crushing, ingredients, made from finely ground raw material, and then feed the cement kiln burning mature material, and then cooked material plus the amount of gypsum (sometimes mixed with mixed materials or additives) made of finely ground. Cement production with raw material preparation methods can be divided into dry (including the semi-dry) and wet (including the semi-wet) are two. ① dry production. While the raw material drying and grinding, or by first drying after grinding into raw material powder dry kiln feed material calcined mature way. But there are also adding an appropriate amount of raw material powder made from raw water ball into the mature material Lepol kiln calcination method, called semi-dry, dry production is still a kind. ② wet production. Gouache ground into raw materials plus the slurry, the feed material of a mature wet kiln burning method. There will be wet slurry prepared dehydrated raw, made into raw block material into the kiln burning sophisticated method, called wet method, it is still wet production of a kind. The main advantage of the production of dry heat consumption is low (eg, dry with a preheater kiln heat consumption of clinker for the 3140 ~ 3768 kJ / kg), drawback is not easy even raw ingredients, shop dust large, high power consumption . Wet production is simple, easy to control raw material composition, product quality, slurry transportation convenience, shop dust and less advantages, disadvantages is the high heat consumption (heat consumption of clinker is usually 5234 ~ 6490 kJ / kg). 3.2 Production Process Cement production, generally can be divided into raw material preparation, clinker and cement made of the three processes. (1) raw material grinding Sub-dry and wet two. Generally use closed-circuit dry operating system that is finely ground raw materials through the mill after entering separator sorting, grinding meal back into the re-grinding operation, and most used materials in both drying and grinding mill process, the use of a tube mill equipment, grinding and unloading in the roller mill, etc. Tube usually wet grinding, grinding and other baseball back in time through the mill is no longer open system, but there is also curved screen with a grader or closed-circuit system. (2) calcined Clinker calcining kilns and equipment are mainly two types of rotary kilns for the production of smaller factories, large and medium-sized plant should adopt the rotary kiln. ① shaft: Kiln shell called up _set_ do not turn the shaft. Mechanized shaft kilns and ordinary points. Common shaft is artificial feeding and artificial feeding discharge or mechanical, manual discharge; mechanical shaft mechanical feeding and mechanical unloading. Mechanical shaft is a continuous operation, its production, quality and labor productivity than ordinary high shaft. In recent years, foreign majority rotary kilns have been replaced, but in the current China's cement industry, kiln still occupy an important position. Policy requirements under the Building Materials Technology, a small mechanized vertical kiln cement plant applications, and gradually replace the common shaft. ② rotary kiln: Kiln shell in horizontal (slope slightly, about 3%), and can be rotary movement known as the rotary kiln. Sub-calcined raw material powder of the dry kiln and calcined slurry (water content is usually about 35%) of the wet kilns. a. dry kiln b. wet kiln For the production of wet cement kilns that wet kilns, wet production is made of raw material moisture content of 32% to 40% of the slurry. As prepared as a liquid slurry, so a good mix between the various raw materials, raw material ingredients evenly, so that firing of high quality clinker, which is the main advantage of wet production. Wet kiln can be divided into wet kilns and long machine with a wet slurry evaporation short kiln, kiln with long wide, short kiln is now rarely used. In order to reduce the long wet kiln heat consumption, kiln equipped with various types of heat exchangers, such as chains, slurry filter preheater, metal or ceramic heat exchanger. (3) grinding Finely ground cement clinker grinding process usually cycle flows (ie, closed operating system). In order to prevent the production of dust, cement plants are equipped with dust collection equipment. Electrostatic precipitator, bag filter and cyclone dust collector such as is commonly used in cement plants dust collection equipment. In recent years, due to the pre-homogenization of raw materials, raw material powder are collecting and other aspects of transportation and use of new technology and new equipment, especially the emergence of the kiln outside the decomposition technique, a dry method of production the resulting new technology. With this new technology to dry wet as much as the quality of the production of clinker production, power consumption is also reduced, has become a national cement industry trends. 3.3 Production Process Example Raw materials and fuel into the plant, sampling and analysis by the laboratory test, and according to quality with homogenization, storage shed in the heap of raw materials. Clay, coal, pyrite powder moisture from the dryer to process index value, by Lifting to the appropriate raw material storage library. Limestone, fluorite, gypsum, after two broken from the elevator into the respective storage library. Laboratory under the limestone, clay, anthracite coal, fluorite, pyrite powder quality, calculation of process recipe, the ingredients through the computer system for raw black raw ingredients from the raw mill for grinding, samples per hour testing a raw material of calcium oxide, ferric oxide, and the fineness of the percentage content, timely adjustments to make the data meet the requirements of process recipes. Grind black raw material put through the bucket elevator into the raw material libraries, laboratories, based on the quality of raw material mill, through a multi-library with library methods and machinery down all of the raw materials, put into two by the elevator raw meal silo, the raw material through all of the library with two, will be expected to be raised to drive the ball into the bunker, located in the shaft from the surface of the pre-water feed control devices into a ball, water ratio, by into a ball of raw material into a plate for the ball. The shaft into the distributor of the ball from the ball of raw material distributed in different locations calcined kiln, clinker after burning out the discharge pipe, scales trigger sent to the clinker crusher for crushing, the laboratory per hour sampling time for clinker chemistry, physics analysis. According to the quality of clinker from the elevator into the corresponding clinker storage, production and business requirements under both market conditions and building materials, laboratory clinker, gypsum, slag, clinker computer batching system by the ratio of cement by the cement mill respectively 425, 525 ordinary portland cement grinding, an analysis of test samples per hour. Grind the cement by the bucket elevator put into the three cement silo, cement quality laboratory conditions according to the mill, through a multi-library with library methods and machinery down all of the cement. The hoist into two cement silos, and then by two cement silos with by the computer control the packaging of cement packing machine, packing out bags of cement stored in the finished product warehouse, and then after passing through the sampling and testing laboratory notice issued by the cement factory.
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Performance indicators
4.1 The main technical indicators of cement (1) gravity and bulk density: the proportion of 3:1 Portland cement, bulk density, typically 1300 kg / cubic meter. (2) Fineness: refers to the thickness of the cement particles. Finer particles, the faster hardening, early strength is also higher. (3) _Set_ting time: mixing cement with water to condense the time required to start, said initial _set_ting time. From mixing with water to condense the time required to complete that final _set_ting time. Initial _set_ting time of portland cement, not earlier than 45 minutes, final _set_ting time later than 6.5 hours. In fact the initial _set_ting time in 1 ~ 3h, while the final _set_ting for 4 to 6 hours. Determination of _set_ting time of cement _set_ting time by a special detector to (4) strength: the strength of cement should be consistent with national standards. (5) volume stability: refers to the hardening process of cement in the volume change of uniform performance. Cement containing impurities, will have non-uniform deformation. (6) heat of hydration: the role of cement and water produces an exothermic reaction in the cement hardening process, constantly emit heat as heat of hydration. (7) Standard consistency: refers to cement paste on the standard test bar sink has a certain resistance when the consistency. Revision 4.2 standard cement China's cement compared to the old standards with new standards there are two main changes: First, the use of GB / T 17671-1999 "cement mortar strength test methods (ISO method)" instead of the current GB177-85 "cement mortar strength test method "; Second Amendment based on ISO strength of our six standard universal cement. (1) GB / T 17671-1999 "cement mortar strength test methods (ISO method)," standard-_set_ting GB / T 17671-1999 of China's equivalent to the development of international standards ISO 679-1989, and on February 8, 1999 release, May 1, 1999 come into effect. GB / T 17671-1999 and GB177-85 belong to the cement mortar strength test "soft training method", that the use of plastic sand, 4X4X160cm prism specimens, specimens will be carried out flexural strength test, break test after two half body and then the compressive strength test. The core difference between the two is composed of different mortar, ISO method uses water-cement ratio is moderate, gray sand ratio is moderate, especially with a graded standard sand, which has been ISO method of testing the strength values than the GB-177 is more close to The use of cement in concrete results. (2) amendments to the standard six main cement a. Cement mortar strength test methods to GB / T 17671-1999 Method Cement products are six standard reference GB / T 17671-1999 way as the strength of cement mortar test methods, instead of the GB 177-85 method. Therefore, GB / T 17671-1999 methods rose to mandatory approach, and GB 177-85 method down to recommended methods. b. Strength of cement grade to grade The old standard to implement a six cement, said cement Kgf/cm2 label, such as 32.5,42.5,42.5 R, 52.5,52.5 R, etc. To implement a new standard six cement Mpa said intensity level, such as 32.5,32.5 R, 42.5,42.5 R, 52.5,52.5 R, so that the value of strength grade concrete 28 day compressive strength with the lowest indicators of the same. New standard also unified planning of our strength grade cement, Portland cement is divided into three grades six types, 42.5,42.5 R, 52.5,52.5 R, 62.5,62.5 R, the other five can be divided into three grades of cement 6 type that 32.5,32.5 R, 42.5,42.5 R, 52.5,52.5 R c. Strength and age indicators for _set_ting the age strength Six new standards for cement cement strength age of 3 days, 28 days two age, each age has flexural and compressive strength indicator.
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Cement History
cement the word evolved from the Latin caementum is the meaning of gravel and stones. Cement history dating back to the ancient Romans used in building a mixture of lime and volcanic ash, the mixture of cement and modern lime ash is very similar. It is made of crushed stone cemented with concrete, not only higher strength after hardening, but also to resist the erosion of fresh or brackish water. For a long time, as an important cementing material, widely used in construction. 1756, British engineer J. Smeaton some lime in the water in the study of the characteristics of hardening found: For hydraulic lime must be used to burn limestone containing clay; masonry mortar for underwater construction, the most the ideal composition is hydraulic lime and volcanic ash dubbed. The discovery of this important research and development of modern cement laid a theoretical foundation. In 1796, British J. Parker, baked with a cement marl, brown appearance, much like the Roman mixture of lime and volcanic ash, named for Roman cement. Because it is the use of marl as a natural raw material, without direct firing from the ingredients, also known as natural cement. Has a good hard and fast coagulation properties of water, especially for contact with the water project. 1813, the French civil engineer Picasso found a lime and clay by three to one made of cement mixed performance of the best. In 1824, British construction workers to J. Aspen Putin has made Portland cement patents. He used limestone and clay as raw material, by a certain percentage tie, lime-burning kilns in the similar maturity within the calcined material, and then finely ground made of cement. Because of the color of hardened cement and Portland, England on the island where the stone used in construction are similar, was named Portland cement. It has excellent construction performance, a landmark in the history of cement. In 1907, France Bi Aili iron ore, bauxite aluminum instead of clay, limestone, firing into the cement mix. Since this contains a lot of alumina cement, so called "alumina cement." 1871, Japan began to build cement plant. 1877, British Crampton invented the rotary furnace, and in 1885 by Lan Samu reform into a better rotary furnace. In 1889, China's coal mine near Tangshan Kaiping, _set_ up with a Tangshan shaft kiln production of "thin cotton soil" plant. 1906 in the plant based on a start of new cement company, an annual output of cement, 40,000 tons. 1893, and the Inland Sea of Japan Hideyuki Endo three Zhen invented two of Portland cement are not afraid of water. The 20th century, people continue to improve the performance of Portland cement, while the successful development of a number of special construction for the cement, such as alumina cement, special cement. Varieties of cement worldwide has grown to 100 kinds in 2007, the annual output of cement of about 20 million tons. China in 1952 developed the first unified national standard to determine the production of cement to the principle of multi-label varieties, and Portland cement contained in the main mineral composition of its changed silicate cement, and later renamed the silicate salt, cement so far. In 2007 China's cement output of about 1.1 billion tons.
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Purchase and use of decorative concrete
6.1 varieties of decorative concrete Decorative cement commonly used in surface decoration of buildings, the construction is simple, easy style, easy maintenance, low price. There are several varieties: (1) white Portland cement: the calcium silicate as the main ingredient, add a small amount of iron from finely ground clinker and the amount of gypsum. (2) color Portland cement: white high-quality white Portland cement clinker and gypsum, mixed with pigments, additives made of finely ground together. Commonly used in color mixing pigments with iron oxide (red, yellow, brown, black), manganese dioxide (brown, black), chromium oxide (green), cobalt blue (blue), ultramarine blue (indigo), peacock blue (sea blue ), carbon black (black) and so on. Decorative cement and Portland cement is similar to the construction and conservation of the same, but easier to pollution, equipment tools must be clean. 6.2 use and purchase In the home decoration, floor tiles, wall tiles and other masonry to be used in paste and cement mortar, which not only can enhance the surface adsorption capacity of wood and grass-roots, but also protect the internal structure, and can serve as a building surface leveling layer of hair, Therefore, in the decoration works, cement mortar is essential materials. Many customers believe that the ratio of cement mortar, the greater the total, the stronger its adhesion, it is often used in cement, the amount of disagreement with the decoration company. In actual fact, to paste ceramic tile, for example, if the cement grade is too large, when the condensation cement mortar, the cement absorbs water, when the surface layer of the tile to absorb water is too easy to crack, to shorten life. General should be cement mortar: sand = 1:2 (volume ratio), the ratio to mix. Currently on the market many kinds of cement, a silicate cement, ordinary portland cement, slag cement, etc., commonly used in home decoration is Portland cement. 6.3 Avoid using the eight cement (1) Avoid damp hard knot Hard knot wet cement will reduce or even lose their original strength, so the specification, the factory more than three months should be reviewed tests of cement, according to test results to use. Into groups that have been wet or hard knot of cement to be used after sifting, screening out the fine, or grind small clumps after rubbing is generally used for minor works of masonry mortar or plaster mortar. Touch or pinch of a cement powder that clumps, may be appropriate to reduce the intensity level of use. (2) avoid exposure to Quick-drying Such as concrete or plaster after operation by exposure, with the rapid evaporation of water, its strength will be reduced or even completely lost. Therefore, the pre-construction cleaning must be strictly and fully wet grass roots; after construction should be strictly coverage, according to the specification water conservation. (3) avoid negative temperature cold Ban Cheng concrete or mortar, if cold, it can not be cement hydration, and expansion of water ice, the concrete or mortar will gradually deepen the powder was crisp outside to the inside damage, should be strictly in accordance with "Construction winter construction procedures "(JGJ104-97) construction. (4) Avoid high temperature hot Solidified layer of mortar or concrete structures, such as high temperatures often in hot conditions, there will be loss of strength, which is due to high temperature conditions, the cement of calcium hydroxide will break down; In addition, certain aggregate at high temperatures also will break down or volume expansion. For a long period of high temperature applications, you can use regular brick mortar or concrete for isolation protection. Experience higher temperatures, should be using a special heat-resistant concrete pouring, the mud can be mixed without a certain amount of finely ground heat-resistant material. (5) Avoid soft grass-roots dirty Cement with hard, clean grass-roots firmly bond or bond together, but the adhesive bond strength of its grass-roots level of the smooth face. Construction on the smooth grass-roots, hemp must be pre-cutting hair brush hit the net, can the cement and grass-roots firmly bonded. Grass-roots on the dirt, greasy, acid and other substances, will play a role in isolation, must be carefully washed clean, brush a prime after the first slurry, add a touch of mortar or concrete pouring. Cement in the solidification process to produce contraction, and in the wet and dry, hot and cold process of change, with loose, weak and very suited to the grass-roots change in the volume, the inevitable happened hollowing or cracks, making it difficult to firmly bond. Therefore, wood, slag cushion and the cushion so dust is not firmly bonded with mortar or concrete. (6) avoid impure aggregate As concrete or cement mortar of sand and gravel aggregate, if there is dust, clay or other organic impurities will affect the cement and sand, stone bond strength between the bond, which eventually will reduce the compressive strength. So, if the impurity content exceeds the standard requirements, must be cleaned before use. (7) avoid thick gray water more People often overlook the impact of water on the strength of concrete construction for easy pouring, and sometimes not seriously implement the mix, while the concrete mix is very thin. As the hydration of cement required for the weight of the water is only about 20% of the excess water evaporates, it will leave many in the concrete pores, these pores will reduce the strength of concrete. Therefore, under the premise of protection of dense pouring, mixing water should be minimized. Many people believe that the use of cement plaster, plaster layer of the dosage, the more the more robust. In fact, the more the amount of cement, mortar, more thick, plaster layer the greater the amount of volume contraction, resulting in cracks more. In general, the plaster should be first with 1: (3-5) thick mortar screed, and then 1: (1.5-2.5) of cement mortar thin surface layer, avoid using too much cement. (8) avoid corrosion by the acid Acid with calcium hydroxide cement and the reaction will occur, the resultant volume of loose, expansive, easily hydrolyzed with water after the powder. Resulting in concrete or plaster layer corrosion gradually disintegrated, so the cement avoid corrosion by the acid. Occasions in contact with acid or container, use acid-resistant mortar and concrete acid. Slag cement, fly ash cement and cement have good acid resistance, preference should be given three cement mortar and concrete acid preparation. Stringent requirements of acid corrosion of the project does not allow the use of ordinary cement.
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Note the use of cement "four point"
After the completion of the purchase of cement, does not mean that has been done! Lafarge experts reminded consumers, the correct _select_ion of qualified cement, but also with proper use. In this regard, the experts made the following recommendations: First, pay attention to the rational ratio of mortar. For example, according to the use of the site such as wiping the walls, floor tiles stickers, stickers, etc. to choose the right mortar wall ratio, a good mortar mix to each two hours after use is appropriate. Second, the _select_ion of building materials on the market dedicated mortar sand, especially sand to control the quality of clay, clay content will reduce the adhesion level. Third, the tiles should be fully soaked before use (two hours) to dry, avoid water loss due to lower strength mortar; tile shop suitably dry, wet wall should shop. Fourth, the mortar mix should be uniform, mixing mortar recommended in 2 hours and 30 minutes of use. The new national standard GB175-2007 Cement Universal Portland Cement 1 Scope This standard provides a common definition and classification of Portland cement, components and materials, the intensity level, technical requirements, test methods, inspection rules, and packaging, labeling, transport and storage and so on. This standard applies to general-purpose Portland cement. 2 Normative references The following documents contain provisions which through reference in this standard to become the standard terms. For dated references, subsequent amendments (excluding corrections) or revisions do not apply to this standard, however, encourage the parties to the agreement according to the study whether to use the latest version of these documents . For undated references, the latest versions apply to this standard. GB/T176 cement chemical analysis (GB/T176-1996, eqv ISO680: 1990) GB/T203 for cement in the granulated blast furnace slag GB/T750 cement pressure steam stability test methods GB/T1345 Cement fineness test methods (sieve analysis method) GB/T1346 normal consistency of cement water, _set_ting time, stability testing methods (GB/T1346-2001, eqv ISO9597: 1989) GB/T1596 for cement and fly ash in concrete GB/T2419 cement mortar fluidity determination GB/T2847 the quality of volcanic ash for cement in the mixture of materials GB/T5483 gypsum and anhydrite GB/T8074 cement surface area method (Bertrand method) GB9774 cement packaging bags GB12573 cement sampling methods GB/T12960 cement component of the quantitative determination GB/T17671 cement mortar strength test methods (ISO method) (GB/T17671-1999, idt ISO679: 1989) GB/T18046 for cement and concrete in the granulated blast furnace slag powder JC/T420 cement raw materials in the chemical analysis of chloride ions JC/T667 cement grinding aids JC/T742 mixed with cement kiln dust in the kiln 3 Definition and Classification The following terms and definitions apply to this standard. Common Common Portland Cement Portland Cement The amount of Portland cement clinker and gypsum, and the provisions of the hydraulic hybrid materials made of cementitious material. 44 Categories This standard specifies the general Portland cement mixed materials according to the variety and ash into Portland cement, ordinary portland cement, slag cement, pozzolana cement, Portland cement, fly ash and portland cement. All varieties of components and code should be consistent with the provisions of 5.1. Of cement grade Universal Cement is the new standard: GB175-1999 "Portland cement, ordinary portland cement", GB1344-1999 "slag cement, Portland cement and fly ash portland cement", GB12958-1999 "portland cement." From April 1, 2001 come into force. 5 components and materials 5.1 Components Common components of Portland cement shall meet the requirements in Table 1. Table 1% Variety code Component Granulated blast furnace clinker + gypsum Slag pozzolanic Limestone and fly ash mixed material Portland cement P • I 100 - - - - P • Ⅱ ≥ 95 ≤ 5 - - - ≥ 95 - - - ≤ 5 Ordinary portland cement P • O ≥ 80 and <95> 5 and ≤ 20a - Slag cement P • S • A ≥ 50 and <80> 20 and ≤ 50b - - - P • S • B ≥ 30 and <50> 50 and ≤ 70b - - - Pozzolana Cement P • P ≥ 60 and <80 -> 20 and ≤ 40c - - Fly ash cement P • F ≥ 60 and <80 - -> 20 and ≤ 40d - Portland cement P • C ≥ 50 and <80> 20 and ≤ 50e The components of a material to meet the standard 5.2.3 of the active hybrid materials, which allows no more than 8% of cement quality standards and in accordance with 5.2.4 of the non-active material or mixture of not more than 5% of cement quality and meet the standard 5.2 .5 kiln dust instead. b The component materials meet GB/T203 or GB/T18046 active hybrid materials, which allows no more than 8% of cement quality and in accordance with section 5.2.3 of this standard mixture of the active material or comply with section 5.2.4 of this standard non-active material or meet the standard mixing section 5.2.5 of the kiln dust in any of the material instead. c The component materials meet GB/T2847 active hybrid materials. d the component materials meet GB/T1596 active hybrid materials. e-component materials on the grounds of the two (or more) in line with section 5.2.3 of this standard mixture of the active material and / or comply with section 5.2.4 of this standard mixture of the non-active material composition, which allows no more than the quality of cement 8% and in accordance with section 5.2.5 of the standard of the kiln dust instead. Hybrid materials when mixed with slag and slag cement dosage may not repeat. 5.2 Materials 5.2.1 Portland cement clinker By the major with CaO, SiO2, Al2O3, Fe2O3 raw materials, ground into fine powder till an appropriate proportion of the proceeds to partial melting of silicate minerals as the main component of the hydraulic cementitious material. Which is not less than 66% calcium silicate mineral, calcium oxide and silicon oxide mass ratio is not less than 2.0. 5.2.2 Gypsum 5.2.1.1 Natural gypsum: should be consistent with GB / T 5483 specified in class G or M class two (or more) or a mixture of gypsum plaster. 5.2.1.2 industrial by-product gypsum: the calcium sulfate as the main component of industrial by-products. Should be tested before use to prove the performance of cement harmless. 5.2.3 active hybrid materials Meet GB/T203, GB/T18046, GB/T1596, GB/T2847 standards of granulated blast furnace slag, granulated blast furnace slag, fly ash, pozzolana mixed materials. 5.2.4 Non-active hybrid materials Activity indicators were lower than GB/T203, GB/T18046, GB/T1596, GB/T2847 standards of granulated blast furnace slag, granulated blast furnace slag, fly ash, pozzolana mixed materials; limestone and sandstone, limestone in which The aluminum oxide content should not exceed 2.5%. 5.2.5 kiln dust Meet JC/T742 requirements. 5.2.6 Grinding When allowed to join the cement grinding aids, the amount should be less than 0.5% of cement quality, aids should be consistent with JC/T667 requirements. 6 intensity level 6.1 Portland cement of strength class is divided into 42.5,42.5 R, 52.5,52.5 R, 62.5,62.5 R six grades. 6.2 Portland cement strength class is divided into 42.5,42.5 R, 52.5,52.5 R four grades. 6.3 slag cement, pozzolana cement, fly ash cement, Portland composite cement strength class is divided into 32.5,32.5 R, 42.5,42.5 R, 52.5,52.5 R six grades. Note: R - early strength (mainly 3d intensity compared with high-strength grade of concrete 7 Technical Requirements 7.1 Chemical indicators Chemical indicators should be consistent with Table 2. Table 2% Variety code Insoluble (Mass) loss on ignition (Wt) sulfur trioxide (Wt) magnesium oxide (Mass fraction) chloride (Mass fraction) Portland cement P • I ≤ 0.75 ≤ 3.0 ≤ 3.5 ≤ 5.0a ≤ 0.06c P • Ⅱ ≤ 1.50 ≤ 3.5 Ordinary portland cement P • O - ≤ 5.0 Slag cement P • S • A - - ≤ 4.0 ≤ 6.0b P • S • B - - - Pozzolana cement P • P - - ≤ 3.5 ≤ 6.0b Fly ash cement P • F - - Portland cement P • C - - a steam pressure of passing the test if the cement, the cement content of magnesium oxide (mass fraction) to allow the relaxation to 6.0%. b If the cement content of magnesium oxide (mass fraction) is greater than 6.0%, the need for cement pressure steam stability test and qualified. c When a lower demand, the index determined by the buyers and sellers to negotiate. 7.2 alkali content (_select_ive index) Alkali content of cement calculated by Na2O +0.658 K2O said. The use of reactive aggregate, the user requests for low-alkali cement, the cement alkali content should not exceed 0.60% or negotiated by the buyers and sellers. 7.3 Physical 7.3.1 _Set_ting Time Portland cement is not less than the initial _set_ting of 45min, the final _set_ting is not greater than 390min; Ordinary portland cement, slag cement, pozzolana cement, fly ash cement and compound Portland cement not less than the initial _set_ting of 45min, the final _set_ting of not more than 600min. 7.3.2 Stability Boiling pot Brewing qualified. 7.3.3 Strength Different intensity levels of different varieties of common Portland cement, the different intensity of the age requirement should be consistent with Table 3. Table 3 units of MPa Compressive strength grade varieties of flexural strength 3d 28d 3d 28d Portland cement 42.5 ≥ 17.0 ≥ 42.5 ≥ 3.5 ≥ 6.5 42.5R ≥ 22.0 ≥ 4.0 52.5 ≥ 23.0 ≥ 52.5 ≥ 4.0 ≥ 7.0 52.5R ≥ 27.0 ≥ 5.0 62.5 ≥ 28.0 ≥ 62.5 ≥ 5.0 ≥ 8.0 62.5R ≥ 32.0 ≥ 5.5 Ordinary portland cement 42.5 ≥ 17.0 ≥ 42.5 ≥ 3.5 ≥ 6.5 42.5R ≥ 22.0 ≥ 4.0 52.5 ≥ 23.0 ≥ 52.5 ≥ 4.0 ≥ 7.0 52.5R ≥ 27.0 ≥ 5.0 Slag cement Ash portland cement Fly ash cement Portland cement 32.5 ≥ 10.0 ≥ 32.5 ≥ 2.5 ≥ 5.5 32.5R ≥ 15.0 ≥ 3.5 42.5 ≥ 15.0 ≥ 42.5 ≥ 3.5 ≥ 6.5 42.5R ≥ 19.0 ≥ 4.0 52.5 ≥ 21.0 ≥ 52.5 ≥ 4.0 ≥ 7.0 52.5R ≥ 23.0 ≥ 4.5 7.3.4 Fineness (_select_ive index) Portland cement and Portland cement to the surface area that is not less than 300m2/kg; slag cement, pozzolana cement, Portland cement and fly ash to Portland cement compound screening I said, 80μm square hole sieve is not greater than 10% or 45μm square hole sieve is not greater than 30%. 8 Test methods 8.1 Components Or choose from the producer according to GB/T12960 more accurate method. In the case of normal production, producers should at least monthly to check on the cement components, the annual average value should be consistent with the standard provisions of Article 5.1, a single test value should not exceed the standard maximum limit of 2%. In order to ensure the accuracy of component measurement results, producers should adopt appropriate procedures and appropriate production methods to verify the reliability of the method _select_ed, and proven methods documented. 8.2 insoluble matter, loss on ignition, magnesium oxide, sulfur trioxide, and alkali By GB/T176 test. 8.3 autoclave stability By GB/T750 test. 8.4 Cl By JC/T420 test. 8.5 standard consistency water, _set_ting time and stability According to GB / T 1346 trial. 8.6 Strength By GB/T17671 test. But pozzolana cement, fly ash cement, Portland composite cement and pozzolana mixed with ordinary portland cement mixed material during the mortar strength test, its water consumption by 0.50 water-cement ratio and mortar flow to determine the degree of not less than 180mm. When the flow is less than 180mm, it should be an integral multiple of 0.01 incremental approach to adjust to the mortar flow of water-cement ratio is not less than 180mm. Mortar fluidity test conducted by GB/T2419, which according to GB/T17671 for mortar preparation. 8.7 Surface Area By GB/T8074 test. 8.8 80μm and 45μm sieve By GB/T1345 test. 9 Inspection Rules 9.1 Number and sampling Cement factory by the same species, with the number and intensity level of sampling. Bagged cement and bulk cement shall be separately numbered and sampling. Each number is a sampling unit. Annual cement production capacity of the factory number defined as: 200 × 104t or more, no more than 4000t is a number; 120 × 104t ~ 200 × 104t, for a number of not more than 2400t; 60 × 104t ~ 120 × 104t, for a number of not more than 1000t; 30 × 104t ~ 60 × 104t, 600t for a number of not more than; 10 × 104t ~ 30 × 104t, not more than 400t of a number; 10 × 104t or less, not more than 200t of a number. Sampling method according to GB12573 for. Continuous take, but also from more than 20 samples of different parts of the same amount, total amount of at least 12kg. When bulk cement transport capacity of more than a few tons of the plant when the serial number provided, to allow more than the number of samples provided tonnage. 9.2 Cement factory Confirmed the technical specifications and packaging of cement quality and meet the requirements before leaving the factory. 9.3 Factory Inspection Factory test items 7.1,7.3.1,7.3.2,7.3.3 bar. 9.4 determine the rules 9.4.1 The test results shall meet the standards for qualified products 7.1,7.3.1,7.3.2,7.3.3. 9.4.2 test results do not meet this standard 7.1,7.3.1,7.3.2,7.3.3 of any one of the technical requirements for substandard goods. 9.5 Inspection Report Factory test report should include test items, fineness, mixed breed and mixed with the amount of material, gypsum and grinding aids of the species and the amount of mixing, is a rotary kiln or kiln production and the contract of the other technical requirements. When the user needs, the producers should be the date of issue in the cement dispatched within 7d 28d strength than the other test results, 32d 28d strength within the report after the test results. 9.6 Delivery and Acceptance 9.6.1 the quality of delivery and acceptance of cement physical sample can be taken based on the results of its tests, can also be the same number of cement producers based on the inspection report. Measures adopted to acceptance by the buyer and the seller agreed and specified in the contract or agreement. The seller has informed the responsibility of the buyer inspection methods. When there is no written contract or agreement, or in the contract, the agreement indicated acceptance of the method, the seller should be indicated on the invoice "to the same number of cement factory inspection report and acceptance based on" word. 9.6.2 to extract the physical test results for samples based on the acceptance, the buyers and sellers should be before shipment or delivery to a common sampling and sign letters. Sampling method according to GB12573 to the sampling number of 20kg, shrinking into halves. Saved by the seller of a 40d, a standard by the buyer according to the requirements of the project and methods of testing. In less than 40d, the buyer that the product quality does not meet the test requirements of this standard, there are objections to the seller, the seller should be preserved both samples sent to the provincial level or another nationally recognized cement above the provincial level quality supervision and inspection bodies Arbitration test. Cement stability arbitration inspection, sampling should be completed within the date of 10d. 9.6.3 the number of cement producers with the inspection report and acceptance based on when the buyer before shipment or delivery of cement in the same number of sampling, the two sides signed to win the title from the seller to save 90d, self-sampling or authorized seller, sign 90d of the seal and save the archive with the number of cement samples. In the 90d, the buyer, when in doubt the quality of cement, the buyer and the seller should send a common recognition of the sample above the provincial level or nationally recognized cement quality supervision and inspection agency for arbitration test. 10 packaging, labeling, transport and storage 10.1 Packaging Can be bulk or bagged cement, bagged cement bag net content 50kg, and the quality mark should be not less than 99%; random sample of the total mass of 20 bags (including bags) should be not less than 1000kg. Other packaging negotiated by both parties, but the bag quality requirements, should meet the above requirements. Cement packaging bags should meet GB9774 requirements. 10.2 logo Cement packaging bags should be clearly marked: the implementation of standards, varieties of cement, code, strength grade, producer names, production license logo (QS) and number, serial number, packaging date, the net content. Bags of cement on both sides should be based on the variety of different colors, printing the name and strength grade cement, Portland cement and ordinary portland cement with red, green slag cement used; pozzolana cement, coal gray portland cement and portland cement with black or blue. Shipped in bulk bags should be marked with the same content presented card. 10.3 Transportation and storage Cement in the transport and storage and shall not be mixed with wet debris, and intensity levels of different varieties of cement mixed in storage to avoid.
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Encyclopedia
shuini Cement cement One kind of finely ground material, add appropriate amount of water into the plastic slurry, both in the air hardening, but also hardened in the water, and be able to sand, stone and other materials securely bonded together to form a solid stone-like body hydraulic cementitious material. Cement is an inorganic non-metallic materials used in one of the largest construction materials and engineering materials used in construction, irrigation, roads, petroleum, chemical, and military engineering. In recent years, industrial countries, the basic requirements for cement production due to saturation, cement production has stabilized or declined, while cement production in China and other developing countries grew rapidly, for example: in 1983 the world's cement production was 900Mt, China's cement production was 100Mt. History About 2000 years ago, the Greek and Romans used in the construction of a mixture of lime and volcanic ash, which reacts slowly in water, hard solid, which is the first application of the cement. Early 19th century, Britain, France and other countries who would stick of lime (or marl) by sintering a hydraulic material, when one of alumina and silica content of 20% and 35%, as a natural cement . This cement firing temperature is low, does not control the ingredients. 1824 British J. Aspen Putin with an artificial mixture of limestone and clay firing a water-rigid cementitious material, it condenses after a hard solid color, appearance, and when the British used in the construction of high quality similar to Portland stone , so called Portland cement. He obtained a patent for this, in 1825, the production plant in the UK. But Putin from the Aspen product. Quality due to low firing temperature is not good enough. Really similar to Portland cement is now the British in 1850 John Sun, IC manufacturing. This marked the beginning of the Portland cement industry. Hundred years, portland cement production process and continuously improve performance, while a large number of new varieties developed so far has grown to more than 100 kinds of cement. In 1889 in Tangshan, China _set_ up its first cement plant, established in 1906 in Tangshan, start a new Cement Company Limited (see start of new cement plants), to create China's cement industry. 1949 cement production 660kt, 1984 reached 120Mt, cement varieties of portland cement from a single development to more than 60 varieties. (See color pictures of China's largest cement ─ ─ Xiangxiang Cement Plant) Portland cement, a class of high-alkaline silicate as the main compound of the general term for hydraulic cement (Portland cement known in the West). It is the calcium (limestone) and aluminum silicate (clay) materials by mixing, grinding in the cement kiln after the high temperature (about 1720K) calcined, obtained cement clinker, gypsum and then shared with the appropriate amount of grinding to a certain fineness and obtained.
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English Expression
n.: concrete, slurry, unsound cement, cement, grey powder, made by burning lime and clay, that sets hard after mixing with water and is used in building to stick bricks together or for making very hard surfaces
French Expression
n. ciment
Thesaurus
concrete Community Shuini Village Shuini Subdistrict
pollution sources