cement is a binder material used for construction that sets, hardens and adheres to other materials to bind together. Cement is seldom used in its own but rather to bind sand and gravel together. Cement mixed with fine aggregate produces mortar for masonry or sand and gravel produce concrete.
types of cement
1. Ordinary portland cement (opc)
2. Portland pozzolana cement (ppc)
3. Rapid hardening cement
4. Quick setting cement
5. Low heat cement
6. Sulphate resisting cement
7. Blast furnace cement
8. High alumina cement
9. White cement
10. Colored cement
11. Air entraining cement
12. Expansive cement
13. Hydrophobic cement
Definition of all types of cement
1. Ordinary portland cement (opc)
In usual construction work, widely used. The composition of ordinary portland cement
. Argillaceous or silicates of
alumina (clay and shale)
. Calcareous or calcium carbonate
(Limestone, chalk and marl)
Uses of ordinary portland cement
. It is used for general construction
Purposes.
. It is also used in most of the masonry
works.
2. Portland pozzolana cement (ppc)
Pozzolans are naturals or synthetic materials that contain silica in reactive forms. It reacts with calcium hydroxide generated by hydrating cement to form additional cementations materials which it is finely divided the composition of Portland pozzolana cement.
. Portland pozzolana cement clinker
. Pozzolanic materials (fly ash,
volcanic ash or silica fumes)
Uses of portland pozzolana cement
. Portland pozzolana cement is
usually used in hydraulic
structures, marine structures,
construction near the seashore,
dam construction etc.
. It is also used in pre-stressed and
post-tensioned concrete members.
. As it gives a better surface finish, it
is used in decorating and art
structures.
. It is also used in the manufacture
of precast sewage pipes.
3. Rapid hardening cement
When finely grounded tri-calcium silicates is present in opc with higher content, it gains strength quickly than opc. This type of opc is called rapid hardening cement. It's initial setting time 30 minutes and final setting time 600 minutes.
Uses of rapid hardening cement
. Rapid hardening cement is mostly used where rapid construction is needed like the construction of pavement.
. It also gives high strength
4. Quick setting cement
Quick setting cement is the cement which sets in a very short time. The initial setting time is 5 minutes and the final setting time is 30 minutes. The composition of quick setting cement.
. Clinker
. Aluminium sulphate (1% to 3% by weight of clinker)
. The Aluminium sulphate increase the hydration rate of silicate.
Uses of quick setting cement
. It is used in underwater construction.
. It is also used in rainy and cold weather conditions.
. It is used a higher temperature where water evaporates easily.
. Used for anchoring or rock bolt mining and tunnelling.
5. Low heat cement
It is a spatial type of cement which produce low heat of hydration during setting. Some chemical composition of ordinary portland cement is modified to reduce the heat of hydration. The chemical composition of low heat cement.
. A low percentage (5%) of tricacium aluminate (C3A).
. A higher percentage (46%) of declaim silicate (C2S).
Uses of low heat cement
. It is used for the construction of dam's,large footing,large raft slab and wind turbine plinths.
. It is also used for the construction of chemical plants.
6. Sulphate resisting cement
Sulphate resisting cement is used to resist sulphate attacks in concrete. Due to the lower percentage of tricacium aluminate the production ofcalcium sulpho aluminates gets reduced.
Uses of sulphate resisting cement
. Construction in contact with soils or ground water having more than 0.2 % or 0.3 % g/l sulphate salts respectively.
. Concrete surface subjected to alternate wetting and drying such as bridge piers,concrete surface in tidal zone ,apron,building near coastal areas.
. Effluent treatment plans, chimney, chemical industries, water storage, sumps, drainage works, cooling towers and sea walls protective works such as breakwaters etc.
7. Blast furnace cement
Portland cement clinker and graunlated blast furnace slag are intergrinded to make blast furnace cement. Maximum 65 percent of the mixture could be comprised by blast furnace slag.
Uses of blast furnace cement
. It is highly sulphate resistant.
. Frequently used in seawater construction.
8. High alumina cement
High Alumina cement is obtained by mixing calcining bauxite (it’s an aluminium ore) and ordinary lime with clinker during the manufacture of OPC. In which the total amount of alumina content should not be lesser than 32% and it should maintain the ratio by weight of alumina to the lime between 0.85 to 1.30.
Uses of high alumina cement
. It is used where concrete structures are subjected to high temperatures like workshop, refractory, foundries etc.
. It also used where the concrete is subjected to frost and acidic action.
9. White cement
White cement is quite similar to Ordinary Portland Cement except for color. Amounts of iron oxide and manganese oxide are low in White Cement. It is expensive then OPC so not economical for ordinary work.
Uses of white cement
. It is usually used in decorative work.
. It can also use for traffic barriers, tile grouts, swimming pools, roof tiles patching materials and terrazzo surfaces.
10. Colored cement
To make 5 to 10 percent of suitable pigments are grinded with OPC. Types of pigments are selected according to the desired color.
Uses of coloured cement
. Colored cement is used for different decorative work.
11. Air entraining cement
It is seen that entrainment of air or formation of gas bubbles while applying cement increases resistance to frost action, fire, scaling and other similar defects. Air-entraining cement is a special type of cement which entrains tinny air bubbles in concrete.
It is produced by grinding minute air entertaining materials with clinker by adding some resinous materials e.g. vinsol resin to ordinary portland cement.
When the water in concrete gets frizzed due to low temperature, it expands. When air-entraining cement, the air voids in concrete provides space for water to expand without cracking concrete. But this type of cement does not provide high strength in concrete.
Uses of air entraining cement
. Especially it is used in areas where the temperature is very low.
. It also resists Sulphet attack.
. It is used where the de-iceing chemical is used.
12. Expansive cement
In the hydration process, the expansive cement expands its volume. It can be possible to overcome shrinkage loss by using expansive cement.
There are three types of expansive cement:
(i). K Type expansive cement
(ii). M Type expansive cement
(iii). S Type expansive cement
K type expansive cement
Raw materials of these types of cement
. Portland cement
. Anhydrous tetracalcium trialuminate sulfate (C4A3S)
. Calcium sulfate (CaSO4)
. Lime (CaO).
M type expansive cement
Raw materials of these types of cement
. Portland cement clinkers.
. Calcium sulfate.
S type expansive cement
Raw materials of these types of cement
. Portland cement clinkers.
. Calcium sulfate (High amount).
. Tricalcium aluminate (C3A) (High bamount).
Uses of expansive cement
. It is used in the construction of the pre-stressed concrete component.
. It is also used for sealing joints
and grouting anchor bolt.
. In the construction of different hydraulic structures, this type of cement is used.
13. Hydrophobic cement.
To resist the hydration process in the transportation or storage stage, clinkers are grinded with water repellent film substance such as Oleic Acid or Stearic Acid. These chemicals form a layer on the cement particle and do not allow water to mix and start the hydration process. When cement and aggregate are thoroughly mixed in the mixer, protective layers break and start normal hydration with some air-entrainment which increases workability.
Uses of Hydrophobic cement
. Usually, it is used in the construction of water structures such as dams, spillways, or other submerged structures.
. It is also used in the construction of underground structures like tunnel etc.
