1. NITTE MEENAKSHI INSTITUTE OF TECHNOLOGY YEHALANKA, BANGALORE-560064
Department of
CIVIL ENGINEERING

2. “lime & Cement”

3. LIME
Lime is a white caustic alkaline substance consisting of calcium oxide, which is obtained by heating limestone with water.

4. Composition of lime
The main constituent of lime is calcium carbonate (CaCo3 )
It is available in nature in the form of limestone , kankar and shells of a sea animals .
Limestone from stone hills is the main source of lime , but shells of sea animals are its purest form.
the other constituents of lime stone are as follows:
Clay: %
Magnesium carbonate : maximum of 30 %
Soluble silica : a small quantity
Alkalis and metallic oxides : 0-5 %
Sulphates : a small quantity
Iron : a small quantity

5. When limestone is burnt, carbon dioxide is given out and quicklime (CaO) is obtained. CaCO3→CaO +CO2 Quicklime is not stable. Water should be poured on quicklime to turn it into calcium hydroxide. This process is known as slaking . During slaking , the following chemical reaction takes place: CaO+H2O = Ca(OH) 2

6. Ca(OH) 2 + CO 2 = CaCO3 + H 2O Slaked lime is known as lime in market.
This is used for civil engg construction with sand and course aggregates, it reacts with carbon dioxide and exhibits a cementing property. The following chemical reaction takes palace:
Ca(OH) 2 + CO 2 = CaCO3 + H 2O

7. CLASSIFICATION OF LIME
Lime is broadly classified into
Fat lime
Hydraulic lime
Poor lime

8. FAT LIME
Fat lime is obtained from burning of limestone,marble,white chalk, seashells,coral…
Fat lime is pure lime .It contains about 95 % of calcium oxide . Thus, Impurities constitute hardly 5 %. When water is added, it slakes vigorously and its volume increases times.
Fat lime has the following properties:
Its colour is perfectly white.
It slakes vigorously.
It has a high degree of plasticity.
It sets slowly in the presence of air.

9. Uses of fat lime Used for whitewashing.
It forms good mortar for brick work and plastering when mixed with sand.
When ground with burnt bricks (surkhi) , it forms good surkhi mortar, which is preferred for building foundations and thick masonry walls.

10. 2. HYDRAULIC LIME
Hydraulic lime is obtained by burning of Kankar(ie dug out from the underground sources)
Hydraulic lime sets by chemically combining(silica,alumina ,ironoxide )with calcium oxide component with water. It contains 5-30% clay.
Its hydraulicity varies depending upon the percentage of clay.
Based on this property, Hydraulic lime is
classified as:
Feeble Hydraulic lime – contains % clay.
Moderately Hydraulic lime - contains 10-20% clay.
Eminently Hydraulic lime - contains % clay.
Uses – lime is preferred for making mortar for plastering work

11. COMPARISON BETWEEN FAT LIME AND HYDRAULIC LIME
ITEM
FAT LIME
HYDRAULIC LIME
Composition
Contains less than 5% clay
Contains % clay
Setting
Sets in the presence of air
Sets in the presence of water
Slaking
Slakes vigorously. Volume is increased times.
Slakes slowly. Increase in volume is marginal
Colour
Pure white
Not so white
Strength
Not so strong
strong
Uses
For plastering, white washing
For making mortar suitable for thick walls and for using damp places

12. POOR LIME
Lime contains More than 30 % Clay is considered as poor lime. It sets very slowly. Its binding property is poor and its colour is dull.
IS : classifies lime into 6 categories from class A to class F as shown below.
CLASS A:
It is an eminently hydraulic lime.
It is normally supplied as hydraulic lime.
When mixed with sand in the proportion of 1: 3 and tested for compressive strength after 14 days and 28 days, standard mortar cubes should have a compressive strength of 1.75 N/ mm2 and 2.8 N/ mm2 .
Used for structural purposes like arches and domes.

13. Class B :
It is a semi- hydraulic lime
It is supplied as quicklime or hydrated lime.
Standard mortar cubed prepared with class B lime and sand in 1: 3 proportion should show 14 days strength as 1.25 N/ mm2 and 28 days strength as 1.75 N/ mm2 .
It is used for masonry works.

14. Class C:
It is fat lime
It is supplied both as quicklime and hydrated lime.
Used for whitewashing and to give finishing coat to plastering walls.
With addition of pozzalanic, it is used for building masonry works.

15. Class D:
It contains a substantial amount of magnesium oxide and is similar to fat lime.
It is used for whitewashing and give the finishing coat to plastered walls. is supplied both as quicklime and hydrated lime.
Class E:
It is also known as Kankar lime. Lime nodules found in fields or mines are burnt to get this class of lime.It is hydraulic in nature and is used for masonry mortar.

16. Class F:It is siliceous dolomite lime and is generally used for the undercoat and finishing coats of plaster.
The details of chemical and physical requirements of above classes of limes are given in IS:

17. How is lime produced? Calcium Carbonate CaCO3 Quicklime Slaked Lime
Carbonation Takes Place
Carbon Dioxide
Reabsorbed
Water Given Off
Burnt in a Kiln at 900oC
Carbon Dioxide Given Off
Quicklime
Calcium Oxide
CaO
Slaked Lime
Calcium Hydroxide
Ca(OH)2
Add to Water

18. Calcium air lime cycle CaO CaCO3 Ca(OH)2 Calcium oxide Quicklime
Calcium carbonate
Limestone
Ca(OH)2
Calcium hydroxide
Hydrated Lime
T > 900°C
+ Water
+ CO2

19. MANUFACTURE OF HYDRAULIC LIME
i) NATURAL HYDRAULIC LIME ii) ARTIFICAL HYDRAULIC LIME

20. MANUFACTURE OF NATURAL HYDRAULIC LIME

21. MANUFACTURE OF NATURAL HYDRAULIC LIME
There are THREE operations involved in manufacture of natural hydraulic lime:
Collection of Kankar ( preparation )
Calcination of Kankar ( burning )
Slaking and Grinding of Burnt Lime ( hydration )

22. Collection of Kankar Nodules Block
The Kankar is an impure limestone and it is used for manufacturing natural hydraulic lime.
The Kankar is available in TWO forms, namely,
Nodules
Block

23. Nodules
The nodules found either on surface of ground or slightly below ground level and easy to collect.
The Kankar in nodular form is considered as superior material for following reasons:
It can withstand heat and rain without disintegration.
It contains higher percentage of clay .

24. Blocks
The blocks of Kankar are found from the underground strata below or on or near the banks of rivers.
The thickness of blocks is usually 50 mm to 300mm.
Both nodules and blocks are quarried with pick-axes & crowbars and its cleaned and converted in to suitable sizes.

25. Calcination of Kankar
The calcination or burning of Kankar to bright red heat is done either in clamps or kilns as in case of manufacture of fat lime.
Limestone may be burnt in any of the following,
i)Clamps
ii)Intermittent kilns
iii)Continuous kilns

26. Slaking and Grinding of Burnt Lime
The slaking of hydraulic lime occurs very slowly .
The grinding of quick lime can be carried out in one of the following ways, with the help of
Hand or
Wooden beaters or
Mills working with bullocks or steam power or
Special machines.

27. Slaking Difference Between Fat Lime and Hydraulic Lime
The required quantity of water for slaking is added at a time and usage of water quantity is high.
After slaked 1part of lime is converted into 1 1/2 parts in paste form and 2 parts in powder form.
Time taken for slake is about 3 to 4 hours.
HYDRAULIC LIME
The required quantity of water for slaking is added gradually and usage of water quantity is low.
After slaked 1part of lime is converted into 1 parts in paste form and 1 1/2 parts in powder form.
Time taken for slake is about 12 to 48 hours.

28. MANUFACTURE OF ARTIFICIAL HYDRAULIC LIME

29. MANUFACTURE OF ARTIFICIAL HYDRAULIC LIME
If natural raw material is not suitable for the manufacture of hydraulic lime, it is possible to prepare the hydraulic lime artificially.
Following are the TWO methods of preparing the artificial hydraulic lime:
Conversion of Soft limestone
Conversion of Hard limestone

30. Conversion of Soft Limestone
The available limestone is in soft as in chalk form and converted in to powder form and mixed with the required proportion of clay.
It is then burnt in a kiln and slaking is carried out as manufacture of natural hydraulic lime.

31. Conversion of Hard Limestone
The available limestone is in hard then it first burnt and slaked with required proportion of clay to obtain raw material.
This mixture is converted into balls of suitable size and after drying these balls are burnt in kiln.
As this lime is produced after burning twice in kiln, also known as TWICE-KILNED LIME.

32. MANUFACTURE OF HYDRATED LIME
Hydrated lime is a type of dry powder made from limestone. It is created by adding water to quicklime in order to turn oxides into hydroxides. Hydrated lime is most often used to make mortars and plasters. Its chemical name is calcium hydroxide, or Ca(OH) ₂

33. Producing dry calcium hydroxide by slaking finely divided or ground, softly burnt lime by carrying out the blending of slaking liquid consisting of 30 to 50 parts by volume water and 70 to 50 parts by volume organic solvent with the lime at a temperature below 45° C.
Subsequently transferring the reaction mixture into a main reaction vessel where the mixture is heated by means of a heating device to a temperature of from 50° to 70° C.
Carrying out the final reaction in another reaction vessel. In the mixing vessel, the ratio of lime to slaking liquid is selected in a way such that a final reaction temperature of 85° to 110° C. is reached in the final reaction vessel.

34. MANUFACTURE OF FAT LIME
Fat lime is also known as quick lime, for preparation for fat lime first of all a limestone (calcium carbonate) is taken and calcination is carried out. In presence of atmospheric air it gives quick lime. The obtained bulk stone is grained finely to obtain quick lime powder.

35. Pure calcium carbonate from a relatively impure source of calcium oxide, characterized in that the method comprises the steps of slaking the calcium oxide source in water to produce an aqueous hydrated lime slurry.
Treating the slurry by the addition thereto of a water soluble source of anions which anions are capable of forming a salt with calcium ions which salt has a dissociation constant greater than the dissociation constant of calcium hydroxide.
Separating the solid content of the slurry from the liquid fraction content thereof to obtain a substantially solids-free solution of calcium ions and anions.
Intimately contacting the solids-free liquid fraction with carbon dioxide gas at a selected rate to maintain the temperature of the solution within a specific range and to lower the pH of the solution to a pre-set value conducive for the formation of a precipitate of calcium carbonate in which one of the crystalline forms, selected from the group consisting of calcite, vaterite and aragonite, predominates and separating the precipitated calcium carbonate from the mother liquor.

36. ACTIVATED LIME POZZOLANA MIXTURE
Lime in conjunction with burnt clay (pozzolana i.e surki and flyash) is used as a material of construction. This mixture possess superior bond. The activated lime pozzolana mixtures are rapid setting, the initial sets being obtained in 1-2 hr and the final within 24 hr.
The mixtures possess high water resistivity and are easily workable.

37. Cement
A Cement is a binder, a substance used in construction that sets and hardens and can bind other materials together.
Mixture of Calcareous, Siliceous, argillaceous and other substances
Used as binding material in mortar and concrete

38. Chemical Composition of a Cement
Lime %
Silica %
Alumina %
Iron Oxide %
Gypsum to 04%

39. Chemical Composition of Portland Cement
Lime to 67 %
Silica to 25%
Alumina to 08%
Iron Oxide t0 06%
magnesia to 04%
Sulphur trioxide to 03%
Soda and/or Potash to 1.3%

40. Hydration of Cement

41. Hydration of Cement

42. Hydration of Cement

43. Why Hydration of Cement is Important?

44. Manufacturing of Portland
Pozzolana Cement
It is a low cost cement composition that can be admixed with water and hydrothermally closed cured to give acid-resistant products of high compressive strength consisting essentially of, in parts by weight, 1 to 1.5 parts of a calcium oxide material containing at least about 60% CaO, 10 to 15 parts of pozzolanic material containing at least about 30% by weight amorphous silica, and to parts by weight of an alkali metal catalyst and building materials made therefrom as well as the method of making such building materials by closed curing.

45. Types of cement Ordinary portland cement(opc)
Rapid hardening portland cement
Quick setting cement
Pozzuolana portland cement
Low heat cement
Blast furnace cement
White cement
Sulphate resisting cement
Coloured cement

46. Uses of cement It is used in making joints for drains ,pipes.
It is used to prepare RCC structures of building by using reinforcement with cement concrete.
it is used in construction of buildings, bridges, tanks, domes, flyovers, dockyard etc.
It is used to prepare cement mortar for building construction works like masonry, plaster, painting, flooring etc.
It is used to prepare cement concrete for various construction works.

47. Types of Cement
Cements are considered hydraulic because of their ability to set and harden under or with excess water through the hydration of the cement’s chemical compounds or minerals
There are two types:
Those that activate with the addition of water
And pozzolanic that develop hydraulic properties when the interact with hydrated lime Ca(OH)2
1.Pozzolanic: any siliceous material that develops hydraulic cementitious properties when interacted with hydrated lime.
2.HYDRAULIC CEMENTS:
Hydraulic lime: Only used in specialized mortars. Made from calcination of clay-rich limestones.
Natural cements: Misleadingly called Roman. It is made from argillaceous limestones or interbedded limestone and clay or shale, with few raw materials. Because they were found to be inferior to portland, most plants switched.

48. Portland cement: Artificial cement
Portland cement: Artificial cement. Made by the mixing clinker with gypsum in a 95:5 ratio.
Portland-limestone cements: Large amounts (6% to 35%) of ground limestone have been added as a filler to a portland cement base.
Blended cements: Mix of portland cement with one or more SCM (supplementary cemetitious materials) like pozzolanic additives.
Pozzolan-lime cements: Original Roman cements. Only a small quantity is manufactured in the U.S. Mix of pozzolans with lime.
Masonry cements: Portland cement where other materials have been added primarily to impart plasticity.
Aluminous cements: Limestones and bauxite are the main raw materials. Used for refractory applications (such as cementing furnace bricks) and certain applications where rapid hardening is required. It is more expensive than portland. There is only one producing facility in the U.S.

49. CEMENTS AND THEIR USES Portland Pozzolana Cement 53 Grade Cement
They are used to gain compressive strength with age.
They are used to give better workability during preparation of concrete.
They have good tensile strength.
53 Grade Cement
These cements are used where high early strength in 1 to 28 days are required.

50. MORTAR

51. LIME MORTAR

52. PREPARATION OF LIME MORTAR

53. CEMENT MORTAR

54. PREPARATION OF CEMENT MORTAR