Project Cover All The Processes, Issues, Requirement And Inputs Of A Cement Manufacturing

The history of cement itself goes back thousands of years. The first sign of cement use comes from the Egyptians, with the use of lime as the “calcareous adhesive”, which they burnt and powdered and can be found cementing the pyramids together still. The Greeks were the next to use lime mortar, “prepared much as it is prepared today.” They also found that certain volcanic deposits combined with water gave increased strength and durability to the mortar. This technological advance was copied by the Romans who were able to make an “admirable hydraulic cement” as they saw constructing a building out

When reading of the concrete that the ancient Romans used, and learning of their unique mixture of volcanic ash and slaked lime (“pozzolana”) I find it most interesting that this concrete still proves to be standing in some places today! It is said to be less sturdy than what we use here in America (Andrews, 2012) but no doubt it gave modern civilization the ingenuity to create what we use today.

There are five different types of cement in the dental field each is versatile in their properties, uses, and mixing techniques. Many were traditionally used for routine cementation through the nineteen ninety’s and since have been replaced by newer makeup and mixing techniques. The selection of cement for a specific procedure requires knowledge of the chemical and physical properties of each particular cement for the specific restorative process to be performed.

Concrete is a composite material used widely in the construction industry. Concrete is basically a mixture of cement, water, aggregates and admixture (sometimes). Cement is a fine gray powder that consists of oxidizes calcium, silicon and aluminum. The aggregate used is normally gravel, crushed stone or sand. Admixture is a solid or liquid substance that gives a certain characteristics of the concrete. The cement reacts with water chemically and binds the aggregates together through a process called hydration during hardening or curing of concrete. It means that water helps in the hardening of the concrete while the cement bind the aggregate and also react with water to form a solid mass.

Consider a modern cement works - it probably produces 1000 - 4000 tonnes of cement a day. Raw materials are dug from the ground and are intrinsically variable - for example limestone from one end of the bench might well contain more clay or silica than limestone from the other end. Fuels are also variable - coal varies in ash and sulphur contents and these days, a works may also burn ancillary fuels such as solvents or car tyres. Variation in raw materials and fuels are likely to result in changes in kiln conditions and consequently, to some extent at least, to changes in the cement quality. Of course, some changes may be for the better, but unless they are maintained consistently, the result may create variability in the final product.

Infrastructure development across the world created demand for construction materials. Concrete is the most important construction material. Concrete is a mixture of various ingredients like aggregates, water and admixture. Aggregate form is the major part of concrete among the entire ingredients used in concrete. The use of normal weight of aggregate such as gravel and granite probably reduces the natural stone deposits and it cause effect on environment. Therefore, it is necessary to explore and to find out suitable material for the replacement and to substitute the natural stone. In foreign countries, the natural and artificial light weight aggregate has been identified

Portland cement concrete has been used in the field of construction since the early Roman empire, but until the early twentieth century transporting concrete to great heights or distances was a big challenge. With the invention of the concrete pump handling concrete using wheelbarrows or buckets became obsolete because they require less man-power and can reach those hard-to-get places with ease. There are three types of concrete pumps being used in construction today: truck mounted, trailer mounted or specialized. Each style of concrete pump has it’s advantages and can be tailor made for different construction applications. There is one drawback in using concrete pumps, standard concrete designs can not be used since it is too viscous and would require much larger pumps to reach the required heights. Therefore, admixtures must be added to the concrete design to change the chemical composition of the concrete to make it more flowable. Admixtures are also used to help slow down or speed up setting time, or reduce the amount of water required in the mix depending on the construction site requirements. With such a vast range of applications that concrete pumps can be used for, concrete construction has seen a great increase in production, efficiency, cost-reduction and even safety.

*Prof. S.D. Bhole et al.., ‘Effect of Micro-Silica on Mechanical Properties of Concrete’. The author concludes the effect of partial replacement of cement by silica fume (micro-silica), studies have been conducted on concrete mixes for M40 grade at 0%, 3%, 6%, 9%, 12% & 15% replacement levels of micro-silica (17).

The function of cement is for isolating production zone and to provide support for the casing [11].Portland cement is made up of calcium oxide (CaO), silicon dioxide (SiO) and water (H2O) which the composition of calcium carbonate is around 75-80 wt% and 20-25 wt% of clay [7],[14].. Compressive strength of Portland cement is developed through hydration. Hydration is chemical reaction between water and cement compound. The rheology and early strength of cement is developed from reaction of aluminate compound at the beginning of hydration. Rate of hydration can be control by adding gypsum. It is for preventing the premature hardening of cement. Gypsum will react with aluminate and hydroxyl ion to form ettrigate. Ettrigate will prevent hydration process by forming needle shaped crystal on the aluminate and creating induction period [11].

In India, there is great demand of aggregates mainly from civil engineering industry for road and concrete constructions. But now a days it is very difficult problem for available of fine aggregates. So researchers developed

In this step also consider the durability of the concrete and the unpredicted external load. This research uses metakaolin and silica fume as the main materials.

Concrete is a vital construction material and establishing the compressive strength is key as the ability to maximise the compressive strength will enhance a structures lifespan. Mortar is formed through the mixing of cement and water before being cast to harden. When the cement and water is mixed the process of hydration occurs forming a paste which then hardens. Once concrete is cast and dries the presence of curing time is important. Not all chemical reactions occur quickly, therefore by curing concrete in water for several days it allows all reactions to complete. Therefore allowing concrete to cure for up to 28 days should ensure that the compressive strength is maximised and it should meet industry standards.

For the most commonly used expansive cements, ordinary Portland cement is used as the cementitious ingredient, however the other types of cement may also be employed. There are several widely used materials for expansive ingredient, these materials can be classified into three main categories by the kind of hydrated products formed due to hydration reaction, formation of ettringite (C_6 AS ̅_3 H_32), formation of calcium hydroxide (Ca(OH)_2), and formation of magnesium hydroxide (Mg〖(OH)〗_2).

Concrete: - It is one of the most widely used construction materials and has a long history of use. Cement is a very important material. Therefore it is necessary to know about it in some details. Generally, cement has been classified by different types depending upon its strength e.g. grade 43, grade 44 etc. Depending upon the requirement of strength of the structure the contractor decides as to which grade is to be used and where. It can be mixed by simple hand mixing method or for large quantities in a computer control batching plants. It is a solid hard mixture produced by adding Portland cement, coarse and fine aggregates and water in proper proportions.

as lime stone or granite, along with a fine aggregate such as sand. The cement commonly Portland cement and