Types of Cement – The different types of cement come from adding various ingredients and changing the proportions of ingredients. These additions and changes allow cement to be used in everything from general construction work to sulfate-resistant applications like sewage systems. Portland cement is only one of five basic types of cement recognized by ASTM, the full list includes:
Type 1 is ordinary Portland cement (OPC), which is a general-use material. Type 2 has moderate sulfate resistance, and its MH variant is moderately resistant to heat of hydration. It’s used in structures that will come into contact with sulfate in water or soil. Type 3 cement is an extra rapid hardening cement. Most concrete takes about a month to get to its full strength after it is poured; this cement becomes harder more quickly. Type 4 is a low heat cement that radiates less warmth as it sets and dries. It’s used for applications where too much heat is undesirable. Type 5 cement is highly sulfate resistant, used for contact with high alkaline soil and water.
Other cement varieties you may run into include:
Types 1A, 2A, and 3A, which are variants of type 1, 2, and 3 cements. These types of cement have air-entraining materials mixed in to make them resistant to moisture damage. Types IL (Portland-limestone), IS (Portland-slag cement), IT (ternary blended), and IP (Portland pozzolana) cement, which are hydraulic and have special properties. IS cement, commonly known as slag cement, includes granulated blast furnace slag and is often used to replace a portion of the portland cement going into the concrete. Type GU, HE, MS, HS, MH, and LH cements, whose names refer to their properties. GU stands for general use, HE for high early strength, and MS and HS for moderate and high sulfate resistance. Similarly, MH and LH refer to cement types with moderate and high heat of hydration.
Across all of these cement types, the most commonly varieties of cement used include:
How many types are there in cement?
Font size: Larger Smaller Hits: 43158 Print Bookmark
Aug 28 Posted on Thursday, 28 August 2014 in Blog Cement is a versatile and complex structure with interchangeable compounds and properties. There are six different types of cement with specific defining behaviours and chemical compositions. Below we look at each type and what makes them unique.
Type I; Ordinary Portland Cement (OPC). This is a general purpose cement with no special properties. It is not Sulphate resistant and creates a fair amount of heat during the hydration process. Type IP; Blended Cement (Pozzolan). This is also a general purpose cement, mainly used for concreting and plastering. Its benefits include: increased long term strength, improved workability and Slump retention, reduced impact of reactive aggregates, reduced risk of cracking due to lower heat of hydration, more durable concrete, reduced greenhouse gases. Type II Cement. Used when mild sulphate resistance and/or a moderate heat of hydration is required. It is also useful for foundation works in areas with moderate levels of Sulphate in the ground water. It usually gains strength at a slightly slower rate than Type I and has a lower heat of hydration than Type I. Type III Cement. Classified as a rapid hardening cement, it is finer than Type I and has a higher C 3 S content and Sulphite level. It also gains “28 day: Strength in 7 days. Useful where the formwork must be quickly stripped or areas that allow traffic early on the road surfaces. Type V (SR Cement. A high sulphate resisting (SR) cement, has a very low heat of hydration and gains strength at a slower rate than type II and I. Used in applications where the soil has high levels of Sulphate/alkali containing compounds in the ground water, sewage systems, piers and platforms on the coast. Class “G” Oil Well Cement. This cement is a specialty cement made for Oil and Gas industry, it has special behavioural properties for high temperature and pressure applications. It is highly resistant to Sulphate and can be blended with a variety of additives to modify behaviour under unique well conditions.
What is cement formula?
|H||H 2 O|
|A||Al 2 O 3|
|N||Na 2 O|
|F||Fe 2 O 3|
|K||K 2 O|
|C 3 S||3CaO·SiO 2 = tricalcium silicate = alite|
|C 2 S||2CaO·SiO 2 = dicalcium silicate = belite|
|C 3 A||3CaO·Al 2 O 3 = tricalcium aluminate|
|C 4 AF||4CaO·Al 2 O 3 ·Fe2O 3 = calcium alumino ferrite|
|C-S-H||Calcium silicate hydrate, a colloidal and mostly amorphous gel with a variable composition; this is the major hydration product of Portland cement, constituting approximately 70 percent of the paste, and is the phase providing most of the strength and binding|
|CH||Calcium hydroxide, a hydration product constituting approximately 20 percent of the paste and, while contributing little to the overall strength, buffers the paste pore solution to a pH of approximately 12.5|
|Afm||Tetra-calcium aluminate trisulfate hydrate, usually with some substitution of Al by Fe and SO 4 substituting for hydroxyl|
Why is cement used?
Where is cement used? – Cembureau Airports | Green roofs | Bridges | Water pipes | Grain silos | Tunnel | Multi storey car parks | Elevated trains | Swimming pools | High rise office buildings | Water reservoirs | Dikes | Wind Power | Roads | Dams | Cargo ships | Statues | Stairs |High rise residential buildings | Houses Cement plays a key, but often unnoticed, role in our lives.
Cement is mainly used as a binder in concrete, which is a basic material for all types of construction, including housing, roads, schools, hospitals, dams and ports, as well as for decorative applications (for patios, floors, staircases, driveways, pool decks) and items like tables, sculptures or bookcases.
Concrete is a versatile and reliable construction material with a wide range of applications. When looking at possible pathways to reduce the carbon footprint of the European cement industry, it is important to examine some of the characteristics of the industry that will influence the availability or viability of emission reduction options. The cement industry is CO 2 -, energy- and material-intensive. Measures to decrease energy consumption and to improve resource efficiency will de facto, reduce CO 2 emissions (hence the focus on CO 2 emissions). The combination of process emissions (emissions released when limestone is transformed into lime during the production process) and emissions from the required thermal energy leads to substantial CO2emissions for each tonne of cement. The cost of constructing a new cement plant with 1 million tonnes of annual capacity is typically more than €150 million. Modernisation of existing cement plants is also very expensive. In addition, and in order to meet European environmental legislation, operations face major investments and operating costs.30% of the cement industry’s total operating expenses relate to energy costs.
- The cost of a new cement plant is equivalent to around three years of turnover, which ranks the cement industry among the most capital-intensive industries.
- Long periods are therefore needed before these large investments can be recovered.
- Plant modifications have to be carefully planned, as typical investment cycles in the sector last about 30 years.
Consequently, achieving the 2050 low-carbon economy roadmap for the European cement industry will be based on balancing recent investments with planning new investments in the coming decades. Although produced from naturally occurring raw materials that can vary widely from plant to plant, cement is a product manufactured in Europe according to a harmonised standard. Despite the existence of specialised segments, many cements are interchangeable, which promotes a competitive cement market. This also means that European production can be very vulnerable to cheaper imports. Cement is mostly locally produced and locally consumed. However, it is also transported over long distances by sea, river and land as plants rationalise and exploit efficiencies of scale. Land transportation costs are significant. Transporting cement costs about €10 per tonne for every 100km by road and around €15 per tonne to cross the Mediterranean Sea 2, Cement consumption is closely linked to economic development in the local region or country. In mature markets, such as Europe, where cement consumption per capita still varies considerably from one country to another, cement sales are dependent on activity in the construction sector, which closely follows (usually after a brief delay) general economic activity.
What is the size of cement?
(3) The Impact of Cement’s Fineness – The size of cement particles directly affects the hydration, setting and hardening, strength and heat of hydration. The finer the cement particles are, the larger the total surface area is and the bigger the area contacting with water is.
- Thus, the hydration will be quick, the setting and hardening will be accelerated correspondingly, and the early strength will be high.
- However, if the cement particles are too small, it is easy for them to react with the water and the calcium dioxide in the air to destroy the storage of cement.
- If the cement is too fine, its shrinkage is large in the hardening process.
Thus, the finer the cement is ground, the more energy will lose and the higher the cost will be. Usually, the grain size of the cement particles is within 7 ~ 200 μm (0.007 ~ 0.2 mm). Read full chapter URL: https://www.sciencedirect.com/science/article/pii/B9781845699550500049
Which chemical is used in cement?
1. Introduction – This paper is an extended version of the Conference Paper published in the Proceedings of the 28th International Symposium on Transport Phenomena, 22–24 September 2017, Peradeniya, Sri Lanka, As described in it, cement is a powdery substance made with calcined lime and clay as major ingredients.
- Clay used provides silica, alumina, and iron oxide, while calcined lime basically provides calcium oxide.
- In cement manufacturing, raw materials of cement are obtained by blasting rock quarries by boring the rock and setting off explosives,
- These fragmented rocks are then transported to the plant and stored separately in silos.
They are then delivered, separately, through chutes to crushes where they are then crushed or pounded to chunks of ∼1/2 inch–sized particles, Depending on the type of cement being produced, required proportions of the crushed clay, lime stones, and any other required materials are then mixed by a process known as prehomogenization and milled in a vertical steel mill by grinding the material with the pressure exerted through three conical rollers that roll over a turning milling table.
Additionally, horizontal mills inside which the material is pulverized by means of steel balls are also used. It is then homogenized again and calcined, at 1400°C, in rotary kilns for the raw material to be transformed to a clinker, which is a small, dark grey nodule 3-4 cm in diameter. The clinker is discharged from the lower end of the kiln while it is red-hot, cooled by various steps, ground and mixed with small amounts of gypsum and limestone, and very finely ground to produce cement,
In the calcination process, in the kiln, at high temperatures, the above oxides react forming more complex compounds, For instance, reaction between CaCO 3, Al 3 (SiO 3 ) 2, and Fe 2 O 3 would give a complex mixture of alite, (CaO) 3 SiO 2 ; belite, (CaO) 2 SiO 2 ; tricalcium aluminate, Ca 3 (Al 2 O 3 ); and ferrite phase tetracalcium aluminoferrite, Ca 4 Al 2 O 3 Fe 2 O 3 with the evolution of CO 2 gas in the Portland cement clinker,
However, there can be many other minor components also since natural clay also contains Na, K, and so on. In the chemical analysis of cement, its elemental composition is analyzed (e.g., Ca, Si, Al, Mg, Fe, Na, K, and S). Then, the composition is calculated in terms of their oxides and is generally expressed as wt.% of oxides.
For simplicity, if we assume that the clinker contains the above four main oxides, they can be simply represented by the Bogue formulae where CaO, Al 2 O 3, Fe 2 O 3, and SiO 2 are denoted as C, A, F, and S, respectively, In this notation, alite (tricalcium silicate), belite (dicalcium silicate), celite (tricalcium aluminate), and brownmillerite (tetracalcium aluminoferrite) are represented by C 3 S, C 2 S, C 3 A, and C 3 AF, respectively.
- If we analyze the elemental composition of Ca, Al, Fe, and Si, usually from X-ray fluorescence spectroscopy, then we express them as wt.% of their respective oxides.
- For example, if the experimentally determined clinker composition is CaO = 65.6%, SiO 2 = 21.5%, Al 2 O 3 = 5.2%, and Fe 2 O 3 = 2.8%, then Bogue calculations would give C 3 S = 64.7%, C 2 S = 12.9%, C 3 A = 9.0%, and C 4 AF = 8.5%, respectively,
However, cement contains water (H 2 O), sulphate (SO 3 ), sodium oxide (Na 2 O), potassium oxide (K 2 O), gypsum (CaSO 4 ·2H 2 O), which are denoted as H, S, N, K, and CSH 2, respectively. Note that gypsum (calcium sulphate dihydrate) is considered as CaO·SO 3 ·2H 2 O and hence its notation is CSH 2,
As such, approximate composition of the cement clinker is different from the above values and is depicted in Table 1, There are several different types of cements of which Portland cement, Siliceous (ASTM C618 Class F) Fly Ash, Calcareous (ASTM C618 Class C) Fly Ash, slag cement, and silica fume are the major types,
They differ from their chemical composition. Table 2 gives the compositions of the above cement types in terms of SiO 2, Al 2 O 3, Fe 2 O 3, CaO, MgO, and SO 3, and the remaining can be other materials such as Na 2 O and K 2 O. Note that SO 3 stands for oxide of S, where S is derived from gypsum (CaSO 4 ·2H 2 O).
Who discovered cement?
The History of Portland Cement – Cement as we know it was first developed by Joseph Aspdin, an enterprising 19th-century British stonemason, who heated a mix of ground limestone and clay in his kitchen stove, then pulverized the concoction into a fine powder.